第28巻 第３号 平成12年９月
内容説
住民主体の健康づくり： 熱帯医学の知のモラル（英文）石川 信克 …………………………………………………………………………………………… ‑原著
インドネシアのスマトラにおけるブユ（双翅目： ブユ科）相調査成績（予報）（英文）高岡 宏行，M ohamad Yunus，Upik K. Hadi，Singgih H. Sigit，宮城 一郎 ………… ‑タイで採集されたブユ（双翅目：ブユ科）１新種の記載および新しく記録された９種について（英文）Chaliow Kuvangkadilok，高岡 宏行 …………………………………………………………… ‑Role of Anopheles subpictus as a Primary Vector of Malaria in an Area in India
Soumendranath Chatterjee and Goutam Chandra …………………………………………… ‑The Effect of Repeated Four M onthly Treatments on the Prevalence and Worm
Burden of Ascaris, Trichuris and Hookworm Infections in an Endemic Area
Norhayati Binti Moktar, Pakeer Oothuman and Fatmah Mohd Salleh ………………… ‑報
酸処理と QC‑PCR 法を用いた Toxoplasma gondii の tachyzoite と bradyzoite の同定（英文）畑英一，青才 文江，Mun Hye‑Seong，Chen M ei，小林仁，仁，矢野 明彦 …………………………………………… ‑Anuar Abdullah Khairul，窪沢

会報・記録
2000（平成12年）年度日本熱帯医学会役員名簿（2000年６月９日現在） …………………………
日本熱帯医学会雑誌編集委員名簿 ……………………………………………………………………… ‑投稿規定 …………………………………………………………………………………………………… ‑著作権複写に関する注意 …………………………………………………………………………………

S EP T EMB ER 2 0 0 0

CONTENTSJapanese Journal of Tropical M edicine and Hygiene Vol. 28 No. 3

総短V OL. 2 8 NO. 3

Review
Ishikawa, N.
Ethics of Tropical Medicine: People‑Centered Health Promotion Reflections from20 Years Experiences of Medical Cooperation in Bangladesh …………………………………

‑Original article
Takaoka, H., Yunus, M., Hadi, U.K., Sigit, S.H. and Miyagi, I.
Preliminary Report of Faunistic Surveys on Black Flies (Diptera: Simuliidae)
in Sumatra, Indonesia …………………………………………………………………………………

‑Kuvangkadilok, C. and Takaoka, H.
Taxonomic Notes on Simuliidae (Diptera) from Thailand:Description of a
New Species and New Distributional Records of Nine Known Species ………………………

‑Chatterjee, S. and Chandra, G.
Role of Anopheles subpictus as a Primary Vector of Malaria in an Area in India …………

‑

Moktar, N.B., Oothuman, P. and Salleh, F.M.
The Effect of Repeated Four Monthly Treatments on the Prevalence and Worm
Burden of Ascaris, Trichuris and Hookworm Infections in an Endemic Area ………………

‑

Research Note
Hata, H., Aosai, F., Mun, H‑S., Chen, M., Kobayashi, M., Khairul, A.A.,
Kubosawa, H. and Yano, A.
Identification of Toxoplasma gondii Tachyzoites and Bradyzoites by a Quantitative
Competitive Polymerase Chain Reaction Method after the Acid Treatment ………………

‑September 2000

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Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 153‑156

Review

ETHICS OF TROPICAL MEDICINE:PEOPLE‑CENTERED HEALTH PROMOTION
REFLECTIONS FROM 20 YEARS EXPERIENCES
OF M EDICAL COOPERATION IN BANGLADESHNOBUKATSU ISHIKAWA MD, MSc, Ph.D.
The Research Institute of Tuberculosis
Japan Anti‑Tuberculosis Association

I would like to approach this giant theme from my
own experience in Bangladesh and the ethical reflections for the last 20 years for tuberculosis control. I
would especially address to young people who are interested in studying for the health promotion in the tropics.
My talk can be summarized with the following 4 key
terms:1) Go to the people, 2) Health by the people, 3)
DOTS and HSSR, and 4) Institutional Capacity inJapan.
Go to the People
To make an effective work or study, we needalways to have a close contact with the fields where
people live, and to keep learning from the fields. For
example, if we want to do any study in the tropics andprepare a questionnaire in Japan,we need to know that
our knowledge may be limited and needs to be largely
changed according to the real needs of the people. Our
attitude should be that we are trying to listen to thepeople and to find the problems and share the findings
together with the people. In other words, our work or
study should not beʻ
our program‑orientedʼ
,but ʻ
peopleʼs
problem orientedʼ
.

(Fig. 1)
I once made a health awareness survey in a southern district of Bangladesh, asking people about theirhealth problems in their villages with a semi‑openquestionnaire. The answers were recorded as they said,
and classified later as ʻ
preventiveʼ, ʻ
curativeʼor ʻ
nointerestʼ
. For example, ʻ
no toiletʼor ʻ
no safe drinking
waterʼwas classified as preventive, and ʻ
no doctorʼorʻ
no drugsʼwas as curative. They were analyzed according to community group activity with or without health

Figure 1 What is the health problems in your village?
Health awareness rises by group activity andhealth volunteer.
(Ishikawa et al.: Promotion of PHC in Rural
Bangladesh, NATAB, 1995)

volunteer. It was then found that people in a group
activity with health volunteer had more preventive idea
than those without health volunteer. People not in agroup had the least preventive ideas. I have learned that
health awareness grows more in the peopleʼ
s own activities for improvement of their living condition or life
style.
()
I have once assisted a surveyfor a Japanese bacteriologist to conduct a tuberculosis prevalence survey by
the bacteriological examination in rural Bangladesh.
The study area (Manikganj Sub‑district) was typicallyrural,50 km away from Dhaka and had a population of
150,000. I made a sampling of 50 villages,and 7,000 adult
population was selected randomly. Sputum specimens
were collected from people who were screened by asymptomatic survey. The bacteriologist made both

154

smear and culture examination of the specimen for acidfast bacilli, especially Mycobacterium tuberculosis. It
was then estimated that the sputum smear AFB positive
rate was 0.3‑0.5%, and the culture positive tuberculosis
rate was 0.4‑0.6%. Nearly30% of them had a resistanceto any anti‑TB drug, and all of them had a previous
treatment history. Among the cultured specimen,
Atypical M ycobacteria (AM or MOTT) grew in highproportion possibly due to contamination. Theywere ofcourse excluded from the analysis. The findings were ofgreat value and are useful still now as there has been noother study like this since then. The study result was
first reported in Japanese local journal,but the bacteriologist lost his interest in publishing it internationallyas
he was a laboratory oriented researcher and disappointed too much with the partial contamination in thefield survey. I myself was also not much motivated in
the publication simply because I was then busy in primary health project though assisting the survey as acollaborator. Another weakness was that there was no
local ownership for this survey. The results should havebeen shared more in Bangladesh and internationally as
well. In this sense, we made a big mistake.
Health by the People
After the survey in Manikganjpeople asked us how
we would deal with the detected 24 TB patients. Theyrequested us to make a better system of treating TB
patients. I proposed them that I would be ready to help
them if they wanted to develop a system of TB control
in the community with active participation of the community. This was a great chance for me too, as I had
wanted to try a community based TB program somewhere. A chance often comes before us when we arereally looking for it.
(Table 1)
The Manikganj sub‑district consists of 147 villages
with 150,000 population. The medical services were very
limited and the majority of people were using unqualified practitioners for the medical care. A local NGO
called BRAC (Bangladesh Rural Advancement Committee) was actively organizing group activities and about
200 health volunteers (HVs) were already working asbare‑foot doctors in the BRAC health program. But
nothing had been yet done for TB. We planned to makea system of utilizing the HVs. They could screen thesuspects with a chronic cough and give drugs to thepatients. With my minimum advice,this program started in 1984 and it has been continuously sustained in the
sub‑district even after I left the country in 1986. Since

Table 1 Community based TB Program Development(BRAC:1984‑98)
Phase Ⅰ
1984‑89

Phase Ⅱ
1990‑94

Phase Ⅲ
1995‑(98)Thana
Pop.(×1,000)

1

10

60

150

1,800

15,000

VHV
TB patients

200
280

1,500
3,500

10,00013,00066‑79%

81%

86%

Cure%

then I visited there only twice a year, and my local
assistant made monthly supervisory visits (Phase I). I
never thought that the expansion to other areas indifferent settings was possible without the guidance bya
specialist like me. However BRAC, using the experience in Manikganj applied the approach to 10 sub‑districts (Phase II), and then to 60 sub‑districts coveringover 600,000 population currently as a part of national
program (Phase III). As of 1998, the number of thetreated TB patients counts over 13,000, and that of the
HVs involved is about 13,000. This approach has beenvery useful in rural and remote areas where the accessto the government health facilities is limited. WHO has
recognized it and the achievements have been publishedin Lancet by BRAC staff two times. Though I could not
publish any paper on this topic with my name,I am very
proud that the local people have gained the ownership of
the program. We could say ultimately that the local
people are the subjects for their health improvement.
DOTS (national TB program package) and HSSR
The current global strategyfor TB control called as
Directly Observed Treatment,short course (DOTS)has
been derived from the analysis of the successful programs in the world. This package program has an
excellence as policy science in that the government
commitment is given the highest importance;cost effective idea for the available technology is applied; forexample, diagnosis is made simply by microscopic
examination of sputum smear, but most costly but
effective short course regimen of anti‑TB drugs areused; a regular monitoring system is included in the
program and a simplified ʻcure rateʼis used for thecriteria of successful program. The DOTS howeverneeded an operational research on how it could beapplied in Bangladesh.

When I went to see Dr.Ahsan Ali,then the director

155

of national TB program in 1991 for my regular visit to
Bangladesh,he asked for my help to conduct a research,as he was a professor of medicine. Then I proposed him
to do an operational research through a pilot model area
development, as the new TB project had been prepared
under the World Bank and WHO. This big scale project
was being introduced by WHO initiative but no proper
pilot area had been tried.
Two thanas (sub‑districts) near Dhaka were thenchosen for the model trial and TB services wereintroduced at the thana health center. Participatory
action research (PAR) was used for the duration of 2
years. This is a kind of operational research method,used for finding a suitable wayof proposed program andit is also useful to make the staff and people involved
lively through their active participation. The process
and outcomes in this PAR was excitingly greater thanwe expected. Some new ideas were introduced in themain project,and above all,the central managerial staff
gained the experience of supervising the periphery centers and understanding the local reality more deeply
through periodical workshops.

From the above experience, I come to realize thatthe health systems and services research (HSSR) is
veryimportant to make a real impact to the country. At
the same time the real empowerment of the people bothin the government and community can be made throughhealth research.
Institutional capacity in JapanThe last key term is institutional capacity. Thismeans the need for strengthening the institutional capacity in Japan as a base for the field activities. In mycase,
the Research Institute of Tuberculosis has been a basefor my work in Bangladesh. But generally speaking,this capacity is still weak in Japan.
Ethics of Tropical Medicine
Ethics is an attitude to think of the oneʼs own deeds
by standing on the otherʼs standpoint. It can be also anattitude of the dialogue or interaction between thesubject and the object of any action (The Ethics ofKnowledge, by Y. Kobayashi and Y. Funabiki, Tokyo
University Press, 1996). Here lies a basis for hope,peace or social justice. I would like to discuss what
tropical medicine is through ethical reflections based on
my own experiences in Bangladesh in the area of tuberculosis control.

The experiment in the laboratory or analysis at the
study room is one, and the field experiment or fieldstudy is the other. Some people spent most of the timein the laboratory under the name of tropical medicine,and others are too busy working in the fields under thesame name or international health. But I would saythat
both are equally needed for tropical medicine.

The subject or actor of tropical medicine is usuallya researcher outside the tropics or community. In thiscase,local people in the tropics are just an object of thestudy. However a local researcher, workers and evenpeople should be the subject of any research as well.
The external researcher and local people need to cooperate and collaborate equally. There are various kinds of
local people, including local researchers, supervisors,community level workers, and community people. We
need to clarify for whom and with whom we are workTable 2 Perspectives of Tropical M edicine
Present

Future adoption/correction

Scientificground:・Positivist Science ・Applied,
Practical Science

Purpose:・Creation of
new knowledge
・Publication

・Health promotion
・Health system
improvement

M ethods:

・positivism
・Qualitative

・Action oriented・Social science
・Qualitative

Owner:

・Researcher(Authorship)・People(Ownership)

ing, and to whom we should feed back the outcomes of
the research. And we need to be aware that the local
rich or local researcher cannot often represent the local
people.

(Table 2)
Conventionally tropical medicine has been positivist
science. This characteristic is basically important but
we need to know its limitation as well. It has a danger
that the importance of the knowledge often lies only inthe authorship. A new horizon for tropical medicine toovercome this is to strengthen the aspects of appliedscience, social science or qualitative analysis, and tochange of our awareness that the knowledge belongs to
the people or the people have the ownership of theknowledge.

156

CONCLUSION
In summary, the aims of tropical medicine are;towork or conduct a study for better health collaboratively with the people in the tropics;to share equally
the study results;to support the people in the tropics towork and study by themselves for their own healthpromotion;and to share internationally the health problems in the tropics through our work in the laboratoryor publications. For this we need to strengthen more theinstitutional capacity in Japan.

157

Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 157‑166

PRELIMINARY REPORT OF FAUNISTIC SURVEYS
ON BLACK FLIES (DIPTERA:SIM ULIIDAE)IN SUMATRA, INDONESIAHIROYUKI TAKAOKA , M OHAM AD YUNUS , UPIK K. HADI ,SINGGIH H. SIGIT AND ICHIRO M IYAGIReceived February 23, 2000/Accepted June 21, 2000

Abstract: Collections of pupae and larvae of black flies (Diptera:Simuliidae)were carried out in 1992 and1994 at 59 sites in four provinces of Sumatra,Indonesia. As a result,22 simuliid species including 12 species
newly recorded from Sumatra were identified, bringing the total number of simuliid species recorded from
Sumatra to 26. All these species were assigned to the genus Simulium s.l.and placed into three subgenera,i.e., Gomphostilbia (12 spp.), Nevermannia (3 spp.),and Simulium s.str. (11 spp.). Further groupings weremade at the species‑group level within each subgenus. The simuliid fauna of Sumatra is Oriental incharacter,being very closely related to those of Peninsular M alaysia and Java. Infections with mermithids,
microsporidians and/or fungi due to Coelomycidium sp. were found in the larvae of 10 of the 22 black‑fly
species examined.
Key words: Simuliidae, fauna, Sumatra, mermithid, microsporidian fungus

The simuliid fauna of Sumatra,Indonesia was firststudied by Edwards (1925, 1934), who reported nine
black‑fly species. Later in 1977 Dr. Rolf Glatthaar
collected several simuliid species including a new
species from North Sumatra,which was described lateras Simulium glatthaari by Takaoka and Davies (1995a).
In 1992 and 1994 we made surveys on black flies atvarious localities of four provinces in Sumatra, andcollected 22 species, of which three new taxa werealready described (Takaoka and Sigit, 1997).
In this paper we report the results of preliminary
identification of these 22 black‑fly species including 12
ones newly recorded from Sumatra,together with thoseof the examinations of larval specimens for infections
with mermithids, microsporidians and fungi due to
Coelomycidium sp.

COLLECTION M ETHODS AND CLASSIFICATION
The methods of collecting simuliid pupae and larvaein flowing waters and rearing pupae until adults emerged were mentioned in Takaoka (1983). The classification of each black‑fly species was done at the genericand subgeneric levels by the definitions and keys made１
２
３

by Crosskey (1967,1969 ),and at the species‑group levelby those proposed by Takaoka and Davies (1996).
The black‑fly larvae collected were examined
under a dissecting microscope for mermithid,microsporidian and fungal infections. These infections werediagnosed in appearance bythe signs of symptoms of thelarval body characteristic for each group of pathogens(Crosskey, 1990).

COLLECTION DATA
For each site surveyed, collection data such as abrief description of flowing water, water temperature,
altitude, its location, and date, are given below by
provinces (only available data are shown). All samples
were collected by H. Takaoka.
Lampung
Surveys were carried out at two sites (L‑1 and L‑2)
near Mutaralam, and five sites (L‑3 to L‑7) along theroad between Liwa and Gunungkemala in the Barisan
Range.
L‑1. An outlet small stream 0.3 cm wide slowly
running from the pond,shaded,water temperature 23°
C,

Department of Infectious Disease Control, Oita Medical University, Hasama, Oita 879‑5593, Japan ＊:Correspondent author
Department of Parasitology and Pathology, Faculty of Veterinary M edicine, Bogor Agricultural University, Taman Kencana 3,
Bogor 16151, Indonesia
Laboratory of M edical Zoology, Faculty of M edicine, University of the Ryukyus, Nishihara, Okinawa 903‑0215, Japan

158

altitude ca.900 m,at Batu Kebayan,west of M utaralam,
30.Ⅶ.1992.
L‑2. An irrigation ditch ca.1.0 m wide,exposed tothe sun,slowly flowing in a paddy field,water temperature 23°
C,altitude ca.900 m,at Batu kebayan,nearer toMutaralam than L‑1, 30.Ⅶ.1992.
L‑3. A brook ca. 0.5 m wide, shaded, slowly flowing,water temperature 20°
C,just south‑west of Liwa,31.
Ⅶ.1992.
L‑4. A brook 0.3‑1.0 m wide,partially shaded,fast
flowing down on the rocky streambed, just south‑westof L‑3, 31.Ⅶ.1992.
L‑5. A rivulet 0.2‑0.3 m wide, shaded, moderately
flowing on the rocky streambed, water temperature
21°
C, near L‑4, 31.Ⅶ.1992.
L‑6. A creek 2.0‑3.0 m wide, partially shaded,
rapidlyor moderatelyflowing down among large stones,
near L‑5, water temperature 22°
C, 31.Ⅶ.1992.
L‑7. An irrigation ditch 0.3 m wide,exposed to thesun, slowly flowing in a paddy field,water temperature
23°
C, 31.Ⅶ.1992.
Bengkulu
Surveys were maded at six sites around the northern shore of the Lake Ranau.
B‑1. An outlet river 10‑20 m wide,originated fromthe Lake Ranau, exposed to the sun, moderately flowing, water temperature 26°
C, at Bandingagung, 29.Ⅶ.
1992.
B‑2. A small stream 0.3‑0.5 m wide,partially shaded,running in a paddy field,water temperature 22°
C,atDesa Surabaya, near Bandingagung, 31.Ⅶ.1992.
B‑3. A rivulet 0.5‑1.0 m wide,shaded,slowly flowing down in a palm forest and a cultivated land forcoffee plantation, water temperature 26°
C, altitude ca.
350 m, at Dusun Pelawi, along the road from Simpangsender to M uaradua, 29.Ⅶ.1992.
B‑4. A small stream 0.2 m wide,shaded,moderately flowing in the bush down to the Lake,water temperature 23.5°
C, altitude ca. 500 m, near Simpangsender,
along the road from Simpangsender to Liwa,29.Ⅶ.1992.
B‑5. A ditch 0.2‑0.3 m wide, exposed to the sun,slowly flowing,water temperature 24°
C,altitude ca.500
m, near B‑4, 29.Ⅶ.1992.
B‑6. A creek, called Air Mujin, 2.0‑3.0 m wide,
partially shaded,moderately flowing down to the Lake,water temperature 24°
C,altitude ca.500 m,at Tanjungjati, along the road between Simpangsender and Liwa,
29.Ⅶ.1992.

West Sumatra
Surveys were carried out in two areas, one around
Padang and the other around Bukittinggi. In the Padangarea,collections were made at three sites (W ‑1 to W ‑3)along the road between Painan and Taratak runningalong the Indian Ocean coast,at seven sites (W ‑4 to W ‑10) along the road going up from Lubukbargalung to
Lubuksulasih, at one site (W ‑11) along the road from
Lubuksulasih to Talang, and at six sites (W ‑12 to W ‑17) along the road between Lubuksulasih and Alahanpanjang, and at five sites (W ‑18 to W ‑22) between
Alahanpanjang and Surian.
W ‑1. A small stream 0.3‑1.0 m wide, shaded, fastrunning down on the rocky streambed, water temperature 24°
C,altitude ca.120 m,just north of Painan,10.Ⅷ.
1994.
W ‑2. A ditch 0.2‑0.4 m wide, slowly flowing along
the road, shaded, water temperature 25°C, altitude ca.
140 m, approximately half way between Painan andPasarkuok, 10.Ⅷ. 1994.
W ‑3. A brook 1.0 m wide, exposed to the sun,slowly flowing,water temperature 30°
C,altitude ca.120
m, at Tigosakato, Tanjung Kandis, 10.Ⅷ.1994.
W ‑4. An irrigation ditch 0.8 m wide,slowlyrunningalong the road, exposed to the sun, water temperature
22°
C,altitude ca.260 m,about half way from Lubukbargalung to Lubuksulasih, 11.Ⅷ.1994.
W ‑5. A rivulet 0.3 m wide, shaded, moderately
running in the bush,water temperature 19°
C,altitude ca.
960 m, just north of W ‑4, 8.Ⅷ.1994.
W ‑6. A rivulet 0.3‑0.5 m wide, shaded, slowly ormoderately flowing in a pine forest, water temperature
19°
C,altitude ca.1,060 m,just before the mountain pass,back of the restaurant, 8.Ⅷ.1994.
W ‑7. A ditch 0.3 m wide, shaded by bush, slowly
flowing, water temperature 19°C, altitude ca. 1,100 m,
Ⅷ
near the mountain pass, 8. .1994.
W ‑8. A creek 1.0‑3.0 m wide, shaded, moderately
flowing in the forest, water temperature 20°
C, altitude
ca. 1,000 m, just over the mountain pass, 8.Ⅷ.1994.
W ‑9. A stream ca.1.0 m wide,exposed to the sun,moderately flowing, water temperature 19°C, altitude
ca. 980 m, near Lubuksulasih, 8.Ⅷ.1994.
W ‑10. A stream ca. 1.0 m wide, partially shaded,
moderately flowing in an open land,water temperature
20°
C, altitude ca. 950 m, at Lubuksulasih, 8.Ⅷ.1994.
W ‑11. A river 4.0‑5.0 m wide, exposed to the sun,moderately flowing in a paddy field,water temperature
20°
C, altitude 970 m, near Talang, 9.Ⅷ.1994.
W ‑12. A ditch 0.2 m wide,slowly flowing along theroad, exposed to the sun, water temperature 21°
C, alti-

159

tude ca. 1,230 m, near Lubuksulasih, along the road to
Alahanpanjang, 9.Ⅷ.1994.
W ‑13. A ditch 0.3 m wide, exposed to the sun,slowly flowing, 19.5°
C, altitude ca. 1,230 m, 9.Ⅷ.1994.
‑
W 14. An irrigation ditch 0.3 m wide, exposed tothe sun, slowly or moderately running, water temperature 20°
C,altitude 1,280 m,just south of W ‑13,9.Ⅷ.1994.
W ‑15. A stream 2.0‑5.0 m wide,exposed to the sun,slowly flowing in a swampy land, water temperature
18°
C, altitude 1,450 m, at Dusun Rawang Godang, Lembang Jaya, Solak, 11.Ⅷ.1994.
W ‑16. A ditch 0.2‑0.4 m wide, exposed to the sun,slowlyflowing,water temperature 23°
C,altitudeca.1,500
m, at Sungai Silah, Lembang Jaya, Solak, 22.Ⅷ.1994.
W ‑17. A stream 0.4‑0.6 m wide,shaded,moderately
running in a natural forest, water temperature 16°C,
altitude ca. 1,580 m, near W ‑16, just south of the Lake
Dibawah, 21.Ⅷ.1994.
W ‑18. A stream 3‑4 m wide, exposed to the sun,moderately running in a paddy field,water temperature
21°
C, altitude ca. 1,460 m, just south of Alahanpanjang,along the road to Surian, 12.Ⅷ.1994.
W ‑19. A small stream 0.3‑0.5 m wide, exposed tothe sun, slowly running down from a forest and joining
W ‑18, water temperature 20°
C, altitude ca. 1,470 m, 12.
Ⅷ.1994.
W ‑20. A stream 0.4‑1.0 m wide,exposed to the sun,moderately flowing, water temperature 20°
C, altitude
ca. 1,090 m, south‑east of W ‑18, 11.Ⅷ.1994.
W ‑21. A stream ca.1.0 m wide,shaded,moderately
flowing, water temperature 22°C, altitude ca. 1,110 m,‑
Ⅷ
south‑east of W 20, 11. .1994.
W ‑22. A ditch 0.2‑0.3 m wide, exposed to the sun,moderately running along the roadside, water temperature 23°C, altitude ca. 1,110 m, at Surian, 11.Ⅷ.1994.
In the Bukittinggi area, collections were made ateight sites (W ‑23 to W ‑30) in and around the M t.
Singkarak,at four sites (W ‑31 to W ‑34)along the roadfrom Payakumbuh to Kotoalam,and at four sites (W ‑35
to W ‑38) along the road from Bukittinggi to Lubuksikaping.
W ‑23. An irrigation channel 0.4‑0.6 m wide,
exposed to the sun, slowly flowing in a paddy field,
water temperature 25°C, altitude ca. 190 m, at Pasir,
Kekambil, Kayutanam, 14.Ⅷ.1994.
W ‑24. A river ca. 10 m wide, exposed to the sun,moderately or rapidly flowing,water temperature 20°
C,
altitude ca. 560 m, at Airmancuur, along the road from
Kayutanam to Padangpanjang, 14.Ⅷ.1994.
W ‑25. An irrigation channel 0.2‑0.3 m wide, par-tially shaded by bush, moderately flowing, water temperature 17°C, altitude ca. 1,400 m, at Sawararas, near
Koto Rarang, on the northern slope of M t. Singkarak,
15.Ⅷ.1994.
W ‑26. A small stream 0.3 m wide, shaded, moderately flowing down in a natural forest, ca. 300 m southfrom W ‑25, water temperature 16°C, altitude ca. 1,460m, 15.Ⅷ.1994.
W ‑27. A brook 2.0‑3.0 m wide,exposed to the sun,moderately flowing, water temperature 19°C, altitude
ca. 1,400 m, in the M t. Singkarak, at Ganting Singgalang, Tanahdatar, 19.Ⅷ.1994.
W ‑28. A creek 4.0‑6.0 m wide,exposed to the sun,moderately flowing, water temperature 20°
C, altitude
ca. 1,100 m, on the way from Kotabaru to the peak of
Mt. Singkarak, 16.Ⅷ.1994.
W ‑29. An irrigation ditch 0.5‑0.7 m wide, exposedto the sun, slowly flowing, water temperature 26°
C,
altitude ca. 1,000 m, near W ‑28, 16.Ⅷ.1994.
W ‑30. A ditch 0.3‑0.4 m wide, exposed to the sun,slowly flowing along the roadside, at the eastern shoreof the Lake Maninjau, just south of M aninjau, altitude
ca. 500 m, 12.Ⅷ.1994.
W ‑31. A ditch 0.2‑0.3 m wide, exposed to the sun,slowly flowing along the roadside, water temperature
23°
C, altitude ca. 530 m, near Kotoalam, 17.Ⅷ.1994.
W ‑32. A rivulet 0.4‑0.6 m wide, shaded, slowly
flowing in a natural forest, water temperature 22°C,
altitude ca. 570 m, just south of W ‑31, 17.Ⅷ.1994.
W ‑33. A brook 1.0 m wide, exposed to the sun,slowly flowing,water temperature 21°
C,altitude ca.600
m, 17.Ⅷ.1994.
W ‑34. A rivulet 0.5 m wide, exposed to the sun,slowly flowing, water temperature 21°
C,altitude 820 m,
half way between Payakumbuh and Kotoalam,south of
W ‑33, 20.Ⅷ.1994.
W ‑35. A river 10‑15 m wide, partially shaded,
moderately or fastly flowing in a natural forest, watertemperature 23°C, altitude ca. 340 m, in Pasaman, half
way between Bonjol and Lubuksikaping, 18.Ⅷ.1994.
W ‑36. A ditch 0.3 m wide, exposed to the sun,slowly flowing along the roadside, water temperature
23.5°
C, altitude ca. 240 m, at Bonjol, Pasaman, 18.Ⅷ.
1994.
W ‑37. A ditch 0.3 m wide,exposed to the sun,very
slowly flowing in a paddy field,water temperature 29°C,
altitude ca. 300 m, at Tanjung Bunga, just south of W ‑36, 18.Ⅷ.1994.
W ‑38. A rivulet 0.3‑0.4 m wide,exposed to the sun,moderately flowing, water temperature 24°C, altitude
ca. 300 m, at Tanjung Bunga, near W ‑37, 18.Ⅷ.1994.

160

North Sumatra
Surveys were carried out at eight sites along thenorth‑eastern shore of the Lake Toba.
N‑1. A creek 4.0‑6.0 m wide, shaded, moderately
flowing in a forest,water temperature 22°
C,altitude ca.
880 m, at Bandar Baru, Sibolangit, 25.Ⅷ.1994.
N‑2. A creek 6.0‑8.0 m wide, exposed to the sun,moderately flowing, water temperature 24.5°
C, altitude
ca. 650 m, foot of the Mt. Meriah, at Deliserdang, near
Sondi, along the road from Pematangsiantar toPematang Purba, 26.Ⅷ.1994.
N‑3. A small stream 1.0 m wide,exposed to the sun,slowly flowing, water temperature 22.3°
C, altitude ca.
680 m, near N‑2, 26.Ⅷ.1994.
N‑4. An irrigation ditch 0.4 m wide,exposed to thesun,slowlyflowing in the paddyrice field,water temperature 25°C, altitude ca. 960 m, near Seribudolok, 26.Ⅷ.
1994.
N‑5. A creek 2.0‑3.0 m wide, exposed to the sun,moderately flowing, water temperature 19°C, altitude
Ⅷ
1,130 m, at Aek Nauli, near Parapat, 27. .1994.
N‑6. A brook 1.0 m wide,partially shaded,moderately flowing in a pine forest, water temperature 20°
C,
altitude ca. 950 m, at Sualan, near Prapat, 27.Ⅷ.1994.
N‑7. An irrigation ditch 0.5 m wide,exposed to thesun,fastly flowing,water temperature 19°
C,altitude ca.
1,100 m,at Junggadolok,along the road between Porsea
and Prapat, 26.Ⅷ.1994.
N‑8. A creek ca. 4.0 m wide, exposed to the sun,moderately flowing in the paddy rice field, water temperature 21°
C,altitude ca.920 m,at Lunbanjulu,Siruur,
Porsea, 26.Ⅷ.1994.

RESULTS OF COLLECTIONS OF BLACK FLIES AND
EXAM INATIONS OF PATHOGENS IN THE LARVAE
Overall, 22 black‑fly species including 12 species
newly recorded from Sumatra were identified;and thesewere all assigned in the genus Simulium Latreille s. l.,and further placed into three subgenera,i.e.,Gomphostilbia Enderlein, Nevermannia Enderlein and Simulium
Latreille s. str., as treated below. Brief remarks ontaxonomy, distribution and infections were given foreach species following the numbers of specimens
examined. The present results bring the total number ofblack‑fly species recorded from Sumatra to 26,of which
seven are indigenous to Sumatra, six, six, and one arecommon to Java, Peninsular Malaysia, and Thailand,
respectively, four are common to all these three areas,
and two are common to the latter two areas. The
simuliid fauna of Sumatra is thus very similar to thoseof neighbouring areas,in particular,to those of Peninsular Malaysia and Java, both of which are known to be
Oriental in elements (Takaoka and Davies,1995b,1996).
Infections with mermithids, microsporidians andfungi were detected in 10 of the 22 black‑fly species
examined. These are first records of these pathogens inthese 10 black‑flyspecies from Indonesia. Of these,four
simuliid species harboured all these three categories ofpathogens, three had both microsporidians and fungi,
two had either of the latter two pathogens, as noted
below. Most of infected larvae were at the immature
stage, but some were at the mature stage.
Abbreviations used below are as follows: ♀ for thereared female adult and its pupal exuvia; ♂ for thereared male adult and its pupal exuvia;P for pupa;PEfor pupal exuvia;ML for mature larva;IL for immaturelarva. Localities, where black‑fly samples were collected, are shown by the initial of the provinceʼ
s namewith the site number, which correspond to those shownin the collection data. Numbers of larva(e) infected,if
present among the total larvae examined, are shown inparenthesis: larva(e) infected with mermithid(s), microsporidians and fungi due to Coelomycidium sp. areabbreviated as NE, SP, and FU, respectively.
()
Takaokaand Davies, 1995
Simulium (Gomphostilbia) cheongi Takaoka andDavies,1995b:37 (female,male,pupa and larva).
Specimens examined. L‑4:2P, 1PE, 3M L.
Remarks. This species was described from Peninsular Malaysia (Takaoka and Davies,1995b). This is thefirst record of this species from Sumatra.
No infection was found.
1()
Takaokaand Davies, 1995
Simulium (Gomphostilbia) duolongum Takaoka
and Davies, 1995b: 19 (female, male, pupa andlarva).
Specimens examined. N‑2:1 ♂,1P,5M L,13IL;N‑
3:1PE;N‑5:12 ♀, 13 ♂, 2PE, 9ML, 19IL;W ‑8:1IL.
Remarks. S. duolongum was also described from
Peninsular M alaysia (Takaoka and Davies, 1995b).
This is the first record of this species from Sumatra.
No infection was found.
2

3

(
)
Edwards, 1934
Simulium (Eusimulium)friederichsi Edwards,1934:
118 (male).

161

Simulium (Gomphostilbia) friederichsi: Crosskey,
1973: 425; Datta, 1983: 229; Crosskey, 1987: 450;
Takaoka and Davies, 1995b: 161; Takaoka andDavies, 1996:26.
Specimens examined. W ‑3:1 ♀;W ‑10:12 ♀,18 ♂,6M L,9IL;W ‑15:2 ♀,2 ♂,2M L,4IL;W ‑21:1 ♂;W ‑36:
9 ♀, 15 ♂, 26ML, 31IL.
Remarks. S. friederichsi was described from asingle male adult collected from Java (Edwards, 1934).
The female, pupa and larva of this species haveremained unknown for a long time. The male of thisspecies is characterized by the presence of the uniqueornamentation on the scutum, i.e., an elongate median
black vitta and two submedian black spots on thegreyish pruinose ground color. The male specimens
reared from the pupae collected in this survey show
several such scutal patterns, of which one is almost thesame as illustrated for S. friederichsi (Takaoka, 1991).
However,some other scutal patterns are also in a good
agreement with those found in S. siamense fromThailand (Takaoka and Suzuki, 1984) and S.
yaeyamaense from Japan (Takaoka, 1991). The pupae
and mature larvae collected from Sumatra are also very
similar to those of S. siamense. Under these situations,
it should be remembered that the present identification
is tentative until additional samples of S. friederichsi
from the type locality in Java become available fordetailed comparison.
No infection was found.
()
Takaokaand Davies, 1996
Simulium (Gomphostilbia) gyorkosae Takaoka andDavies, 1996:28 (female, male, pupa and larva).
Specimens examined. W ‑15:1 ♂;W ‑18:1 ♀;W ‑25:
13 ♀, 10 ♂, 3PE, 12M L, 21IL; W ‑27: 9 ♀, 6 ♂, 29ML,
89IL (1SP);L‑2:2P, 1ML, 3IL.
Remarks. S. gyorkosae was originally describedfrom Java (Takaoka and Davies,1996). This is the firstrecord of S. gyorkosae from Sumatra. This species isvery similar to S. asakoae described from Peninsular
Malaysia (Takaoka and Davies, 1995b) and there is apossibility that the latter species is mixed in the present
specimens. Further studies are now under way.
Only 1 of the 89 immature larvae collected at W ‑27
was infected with microsporidians.
4

5

(
)
Takaoka and Sigit, 1997
Simulium (Gomphostilbia) padangense Takaoka
and Sigit,1997:69 (female,male,pupa and larva).

Specimens examined. W ‑6: 1 ♀, 3 ♂, 1P, 21M L,
38IL.
Remarks. This species was fullydescribed from thefemale,male,pupal and larval specimens collected from
West Sumatra by Takaoka and Sigit (1997). Its distribution is now restricted to the type locality in West
Sumatra.
No infection was found.
()
Takaoka and Sigit, 1992
Simulium (Gomphostilbia) parahiyangum Takaoka
and Sigit, 1992: 135 (female, male, pupa andlarva);Takaoka and Davies, 1995b:50.
Specimens examined. W ‑9:3ML,19IL;W ‑15:6 ♀,5 ♂, 3P, 4M L, 1IL;W ‑38:1P.
Remarks. Edwards (1934) incorrectly associatedthe larva of this species collected from South Sumatrawith S. varicorne, which was described based upon theunique male specimen collected at the same locality(Edwards, 1925). S. parahiyangum was originally described from Java (Takaoka and Sigit, 1992), and waslater recorded from Peninsular Malaysia (Takaoka andDavies, 1995b).
No infection was found.
6()
Takaoka andDavies, 1995
Simulium (Gomphostilbia) sheilae Takaoka andDavies,1995b:60 (female,male,pupa and larva).
Specimens examined. N‑1:1 ♀;N‑5:1 ♂, W ‑2:2♀, 1 ♂, 1PE, 5ML; W ‑13: 1 ♀, 1 ♂; W ‑15: 3 ♀, 2 ♂,3M L, 4IL;W ‑16:1 ♀, 1ML;W ‑35:1 ♀;L‑4:5 ♀, 5 ♂,3P, 7ML, 4IL.
Remarks. S. sheilae was originally described from
Peninsular M alaysia (Takaoka and Davies, 1995b).
This is the first record of S. sheilae from Sumatra.
No infection was found.
7()
Edwards,
1934
Simulium (Eusimulium) sundaicum Edwards,1934:
122 (female, male, pupa and larva).
Simulium (Gomphostilbia) sundaicum: Crosskey,
1973:425;Datta, 1983:230;Takaoka and Davies,
1995b:161;Takaoka and Davies,1996:19 (female,
male, pupa and larva).
Specimens examined. N‑1: 2 ♂, 1M L; N‑2: 2M L,
1IL;N‑3:1 ♀, 1 ♂, 1PE, 5IL;N‑4:1 ♂, 1P, 1PE, 2M L,
45IL;N‑5:2PS,1ML,5IL;N‑6:1P,1M L;N‑7:2 ♀,1 ♂;W ‑1:28 ♀, 20 ♂, 21ML, 88IL;W ‑3:8 ♀,3 ♂,2P,2M L,
8162

4IL; W ‑4: 2 ♀, 11 ♂, 9M L, 49IL (1NE); W ‑10: 1 ♂,2M L, 13IL;W ‑12:2 ♀, 1 ♂, 2M L, 5IL;W ‑14:9 ♀, 7 ♂,28M L,13IL;W ‑15:10 ♀,10 ♂,27ML,134IL (2SP);W ‑18: 1 ♀, 1 ♂; W ‑19: 1 ♀, 3IL; 1PE; W ‑20: 7 ♀, 6 ♂,14M L, 42IL (1NE, 1SP); W ‑21: 2 ♂, 2P, 3ML, 19IL
(2NE);W ‑22:20 ♀,20 ♂,10M L,30IL;W ‑27:3M L,6IL;
W ‑29:1 ♀,1 ♂;W ‑30:1 ♂,1ML;W ‑33:2 ♀,1 ♂,4ML,
17IL;W ‑34:1M L, 1IL;W ‑36:1 ♀, 4 ♂, 9ML, 34IL;W ‑37: 2IL; W ‑38: 2P, 8IL; B‑2: 5 ♀, 4 ♂, 30ML, 20IL
(2NE);B‑3:23 ♀,18 ♂,2P,43M L,87IL (8NE,5FU);B‑
5:8 ♀, 13 ♂, 11ML, 46IL (3NE);B‑6:3 ♀, 3 ♂, 1ML,
14IL (3NE);L‑2:5 ♀, 5 ♂, 6M L, 10IL;L‑5:2 ♀, 3 ♂,3M L, 7IL;L‑6:1PE, 1ML;L‑7:6 ♀, 9 ♂,14M L (1NE),
21IL (2NE).
Remarks. S. sundaicum was originally describedfrom Java and South Sumatra (Edwards,1934). This is
one of the common species in Sumatra.
M ermithid, microsporidian and fungal infections
were found in several sites.
()
Takaokaand Davies, 1995
Simulium (Gomphostilbia) whartoni Takaoka andDavies,1995b:32 (female,male,pupa and larva).
Specimens examined. W ‑17: 1 ♀, 1P, 7ML, 13IL;
W ‑27:1 ♀;W ‑30:2PE,4ML,15IL;W ‑35:4 ♀,4 ♂,1P,
4M L, 11IL;L‑4:1 ♀, 1 ♂, 2PE, 2M L.
Remarks. This species was described from Peninsular M alaysia (Takaoka and Davies,1995b). This is thefirst record of this species from Sumatra.
No infection was found.
9

10

(
)
Brunetti,
1911
Simulium aureohirtum Brunetti, 1911: 283 (male);
Edwards, 934:134 (female, pupa and larva).
Simulium (Nevermannia)aureohirtum:Ogata,1956:
61;Ogata,1966:129;Crosskey,1987:459;Takaoka
and Roberts,1988:194;Crosskeyand Lowry,1990:
204;Takaoka and Davies,1995b:87;Takaoka andDavies, 1996:5.
Simulium (Eusimulium) aureohirtum:Puri 1933:1;
Ogata and Sasa,1954:325;Ogata,Sasa and Suzuki, 1956:73;Crosskey, 1973:423;Takaoka, 1976:
170;Takaoka, 1979:382 (female, male, pupa andlarva); Datta, 1983: 225; Takaoka and Suzuki,
1984:11;Davies and Gyorkos, 1987:1485.
Eusimulium aureohirtum:Orii, Uemoto and Onishi,
1969:1.
Simulium (Eusimulium) tuaranense Smart andClifford, 1969:40. Syn. by Crosskey 1973.

Simulium (Eusimulium) philippinense Delfinado
1962:47. Syn. by Takaoka 1983.
Specimens examined. N‑3:1 ♀,1P,1M L,18IL;N‑
4:1IL;W ‑3:4ML, 2IL;W ‑12:8 ♀, 7 ♂, 5ML, 44IL;W ‑14: 25 ♀, 10 ♂, 24ML (1FU), 43IL (1SP); W ‑15: 1 ♀,17IL;W ‑21:3IL;W ‑22:4 ♀,3 ♂,8ML,10IL;W ‑31:2 ♀,3 ♂, 2ML, 8IL;W ‑35:1ML;W ‑37:2 ♀, 1 ♂, 1P, 2M L,
29IL;B‑1:1PE;B‑2:1IL;B‑5:4 ♀, 8 ♂;L‑1:6 ♀, 1 ♂,40M L, 98IL;L‑2:1IL.
Remarks. S. aureohirtum is known to be widelydistributed in the Oriental and the southern part of the
Palaearctic Regions (Takaoka and Davies, 1995b).
This species extends its distribution eastwards to theHalmahera Island in the Australasian Region (Takaoka,1996). This species is distinctive among the Oriental
Simuliidae by its autogenous ovarian development(Takaoka, 1989 ). This physiological feature of thisspecies was also confirmed in the populations of
Sumatra by dissecting female flies kept alive in small
plastic tubes with 5% sugar solution for 3‑5 days after
they emerged from the pupae (data not shown).
Microsporidian and fungal infections were found,each in one immature larva.
11

(

)

Edwards,

1934
Simulium feuerborni Edwards, 1934: 129 (male,pupa and larva).
Simulium (Eusimulium)feuerborni:Crosskey,1969:
64;Datta, 1973:367;Datta, 1983:226.
Simulium (Nevermannia) feuerborni: Crosskey,
1987:458;Crosskey and Lowry,1990:213;Takaoka and Davies, 1995b: 86; Takaoka and Davies,
1996:10 (female, male, pupa and larva).
Specimens examined. N‑6:1 ♂,1P,20IL (1FU);N‑
7:3 ♀, 1 ♂, 2M L, 16IL;W ‑14:1 ♀,1IL;W ‑25:15 ♀,26♂, 1P, 12M L, 24IL.
Remarks. This species was originally describedbased on the male,pupal and larval specimens collectedfrom East Java and Bali by Edwards (1934), and thefemale was later described from specimens collectedfrom West Java by Takaoka and Davies (1996). This
species was also recorded from West M alaysia (Takaoka and Davies, 1995b) and from Thailand (Kuvangkadilok et al., 1998). The present specimens are indistinguishable morphologically from the Javanese ones.
This is the first record of this species from Sumatra.
A fungal infection was found in one immature larva.

163

(
)
de Meijere, 1913
Simulium argyrocinctum de Meijere, 1913: 332(female and male); Edwards, 1934: 108 (female,
male, pupa and larva).
Simulium (Simulium) argyrocinctum: Crosskey,
1969:115;Takaoka and Davies, 1996;44 (female,
male, pupa and larva).
Specimens examined. W ‑24: 7 ♀, 8 ♂, 1P, 7PE,
7M L, 7IL;W ‑28:5IL (1SP, 3FU);B‑6:4 ♀, 5 ♂, 8ML,
13IL.
Remarks. This species was described from adultspecimens collected from Java (de M eijere, 1913), andits pupa and larva were described based on the specimens collected from Java and South Sumatra (Edwards,
1934). It is noted that some pupae collected from Westand South Sumatra in this survey showed some variations in the branching schemes of the ten respiratory
filaments on each side. The pupal respiratory filamentsof this species are arranged in five pairs in most pupae,
but in two pairs plus two triplets in some, and even infour pairs plus two individuals in a few others.
M icrosporidian and fungal infections were found in
one site.
12()
Takaoka andDavies, 1995
Simulium (Simulium)bishopi Takaoka and Davies,
1995b:111 (female, male, pupa and larva).
Specimens examined. L‑3:2IL;L‑4:3 ♀;L‑6:1 ♂,2M L.
Remarks. This species was originally describedfrom Peninsular Malaysia (Takaoka and Davies,
1995b). The present specimens agree morphologicallywith the original descriptions. This is the first record of
S. bishopi from Sumatra.
No infection was found.
13()
Takaoka andDavies, 1995
Simulium (Simulium) brevipar Takaoka andDavies,1995b:132 (female,male,pupa and larva);
Takaoka and Saito, 1996:168.
Specimens examined. L‑5:1 ♀,1 ♂,2P,3M L,20IL.
Remarks. This species was originally describedfrom Peninsular M alaysia (Takaoka and Davies,1995b)
and also recorded from Thailand (Takaoka and Saito,
1996). Our survey shows that this species extends its
distribution to South Sumatra.
No infection was found.
14()
Edwards,
1934
Simulium fenestratum Edwards, 1934: 110 (male,pupa and larva).
Simulium (Simulium) fenestratum:Crosskey, 1969:
115;Takaoka and Saito, 1996:166.
Specimens examined. N‑1:1 ♀,1P,1PE,1ML,9IL(1SP); N‑2: 2IL; N‑6: 11 ♀, 13 ♂, 1PE, 15M L, 71IL
(1FU);N‑7:1IL (1FU);N‑8:5 ♀,4 ♂,6ML,33IL;W ‑6:
1 ♀;W ‑8:1 ♀,3 ♂,1PE,2ML,1IL;W ‑9:3 ♀,7 ♂,1PE,
12M L, 41IL (2SP, 1FU); W ‑10: 18 ♀, 12 ♂, 3P, 1PE,
28M L, 72IL (2NE, 1SP); W ‑11: 14 ♀, 10 ♂, 5P, 5M L,
58IL (1NE,1SP,3FU);W ‑13:2 ♀,3 ♂,1PE,3ML,13IL(4FU); W ‑14: 1 ♂, 1M L; W ‑15: 1 ♂, 1IL; W ‑19: 1 ♀,4M L, 27IL (5FU); W‑20: 5 ♀, 8 ♂, 5P, 20ML, 52IL
(1NE, 2SP);W ‑21:2 ♂, 2ML, 32IL (2NE, 1SP);W ‑24:
1 ♀, 1 ♂, 3IL (1FU);W ‑25:4 ♀, 8 ♂, 2PE, 3ML, 2IL;
W ‑27:18 ♀,21 ♂,33M L,236IL (3NE,2SP);W ‑28:1 ♀,1PE,1ML,14IL (3NE);W ‑29:1 ♀,1ML,8IL (1NE);W ‑33: 1 ♀, 1 ♂, 2ML, 24IL; W ‑38: 4 ♀, 5 ♂, 2PE, 2M L,
76IL (2SP);L‑2:8 ♀,8 ♂,13ML,58IL (35NE):L‑4:1P,
2PE, 1IL;L‑6:3 ♂, 1P, 4ML, 23IL;L‑7:2IL.
Remarks. S. fenestratum was described from Westand North Sumatra (Edwards,1934),and later recorded
from Thailand (Takaoka and Saito,1996). The present
larval specimens show bimorphism with regard to thedorsal protuberances on the abdomen,which are present
in one type, but absent in the other type. This bimorphism was found even in the same populations. In
addition, some males had bicolored hind basitarsi whilemost of the other males examined in this survey had
almost darkened ones. Therefore, the possibility is not
ruled out that more than one species are involved in thepresent specimens, representing a species complex.
Further studies are now under way.
Larvae of this species were frequently infected withmermithid,microsporidians and fungi. It is noteworthy
that as high as 60% of the immature larvae examined
were infected with mermithid parasites at L‑2.
15

16

(

)

de Meijere,

1913
Simulium iridescens de Meijere, 1913: 333 (female
and male); Edwards, 1934; 112 (female, male,pupa and larva).
Simulium (Simulium) iridescens: Crosskey, 1973:
427; Crosskey, 1987: 475; Takaoka and Davies,
1996:67 (female, male, pupa and larva).
Specimens examined. N‑1:4 ♀,6 ♂,1P,2PE,3ML(1NE), 18IL (8NE);N‑2:3M L, 1IL;W ‑8:1 ♀;W ‑9:8♀, 5 ♂, 2P, 8ML, 56IL (2NE, 2FU); W ‑10: 3 ♀, 1 ♂,

164

13M L, 63IL (13SP, 6FU);W ‑11:2 ♀, 4 ♂;W ‑17:1 ♂;W ‑20:2P, 2ML, 1IL;W ‑21:1P, 2ML, 10IL;W ‑22:1 ♀;W ‑24:6 ♀,9 ♂,3P,2PE,7ML,14IL;W‑28:1PE;W ‑35:
3 ♂,3PE,2ML,1IL;W ‑38:1P,3ML,6IL;L‑3:26ML;L‑
4:1 ♀,1 ♂,3P,4M L,3IL;L‑5:1IL;L‑6:1 ♀,5 ♂,2ML.
Remarks. This species appears to be one of thewidely distributed species in Sumatra since many samples were collected from North and West Sumatra, as
well as from South Sumatra.
M ermithid, microsporidian and fungal infections
were found.
()
Takaokaand Sigit, 1997
Simulium (Simulium) minangkabaum Takaoka
and Sigit,1997:76 (female,male,pupa and larva).
Specimens examined. W ‑11:6 ♀, 6 ♂, 2PS, 1ML,
18IL;W ‑15:1 ♀,1 ♂;W ‑18:5 ♀,5 ♂,8P,28ML,151IL(1SP).
Remarks. This species was alreadydescribed basedon the female, male, pupal and larval specimens collected from West Sumatra by Takaoka and Sigit(1997).
The microsporidian infection was found in one
larva.
17()
Edwards,1934
Simulium nebulicola Edwards, 1934:114 (male).
Simulium (Simulium) nebulicola: Takaoka andDavies, 1996:71 (female, male, pupa and larva).
Specimens examined. W ‑5:1 ♂, 1PE, 1IL;W ‑6:1♀, 8IL;W ‑7:1P, 1IL;W ‑13:1 ♂;W ‑26:1P, 6IL.
Remarks. This species was originally describedfrom the male specimen collected from East Java by
Edwards (1934). The female, pupa and mature larva
were described by Takaoka and Davies (1996). The
present specimens collected from West Sumatra agree
well morphologically with the descriptions given by
Takaoka and Davies (1996). This represents the new
distributional record of this species from Sumatra.
No infection was found.
18

19

(
)
de M eijere, 1907
Simulium nobile de Meijere, 1907: 206 (male);
Edwards, 1934: 115 (female, male, pupa andlarva).
Simulium (Simulium) nobile: Crosskey, 1973: 428;
Crosskey, 1988:475;Takaoka and Davies, 1995b:
123;Takaoka and Davies,1996:61 (female,male,pupa and larva).
Specimens examined. N‑1:2IL;N‑6:1 ♀,1 ♂,1PE;

W ‑:2 ♀,1 ♂,1P,1ML,1IL;W ‑4:3P,2M L;W ‑10:1 ♀,1 ♂,1ML;W ‑11:1 ♀,1P,1ML,3IL;W ‑20:1ML;W ‑21:
7IL (2NE);W ‑23:4 ♀, 5 ♂, 11M L, 27IL;W ‑24:1 ♀, 1♂;W ‑28:10 ♀,11 ♂,76ML,95IL (1NE,1SP,2FU);W ‑
29:2 ♀, 3 ♂, 1PE, 3ML, 16IL (2NE);W ‑35:1 ♀, 2 ♂,2PE, 1ML, 3IL; W ‑36: 1 ♂, 2M L, 1IL; W ‑38: 1 ♀, 2P,
2PS,2ML,6IL;B‑1:7 ♀,5 ♂,3P,2PE,1ML,14IL;B‑6:18 ♀, 17 ♂, 14ML, 19IL; L ‑2:2 ♀, 1 ♂, 3ML.
Remarks. S. nobile was originally described fromJava (de M eijere, 1907),and later recorded from South
Sumatra (Edwards,1934). This species was also recorded from Peninsular M alaysia and Sabah (Crosskey,1973). This is one of the common black‑fly species in
Sumatra.
Mermithid, microsporidian and fungal infections
were found.
()
Takaokaand Sigit, 1997
Simulium (Simulium) sumatraense Takaoka andSigit, 1997:72 (female, male, pupa and larva)
Specimens examined. W ‑17: 1 ♀, 1 ♂, 1P, 3M L,
19IL;W ‑19:1 ♀,1ML,3IL;W ‑26:1P,6IL;W ‑27:4 ♀,1♂, 1PE;W ‑30:1 ♂, 1PE, 9IL.
Remarks. S. sumatraense was described based on
the female, male, pupal and larval specimens collectedfrom West Sumatra by Takaoka and Sigit (1997). This
species is very similar to S. nebulicola but differs fromthe latter species by the longer pupal respiratory filaments and the presence of the terminal hooks on the
pupal abdomen, as mentioned by Takaoka and Sigit(1997).
No infection was found.
20()
Takaoka and Davies,
1995
Simulium (Simulium) tani Takaoka and Davies,
1995b:137 (female, male, pupa and larva).
Specimens examined. W ‑9:1 ♀;W ‑11:1PS, 1M L;
W ‑19:1 ♀, 1ML, 2IL;W ‑27:1IL;W ‑33:1ML.
Remarks. This species was originally describedfrom Peninsular Malaysia (Takaoka and Davies,1995b)
and also recorded from Thailand (Takaoka and Saito,
1996). It is noted that there are slight differences in the
thickness of six pupal respiratory filaments on each side
between the present specimens and Malaysian ones.
This is the first record of this species from Sumatra.
No infection was found.
21

165

(
) sp. nr.
Edwards, 1934
Specimens examined. N‑6:1P;W ‑24:2 ♀,3 ♂,2P,
1PE, 5ML, 46IL (1SP);W ‑27:1IL;W ‑35:4 ♀, 8 ♂, 4P,
8M L, 82IL;B‑6:15 ♀, 15 ♂, 1PE, 11ML, 39IL (1FU).
Remarks. This species is almost indistinguishable
morphologically from S. eximium reported from Java
(Takaoka and Davies, 1996) except a few characters
including the adult male abdomen with five pairs of
dorsolateral silveryspots each on segments 2,4,5,6,and
7 in this species (c.f. four pairs of such spots each on
segments 2,5,6,and 7 in S. eximium). Interestingly,theadlut male specimens collected from Flores in theLesser Sunda Islands have the same spot pattern as
found in this species from Sumatra (Takaoka, unpublished data). Hadi et al. (1996) have given a cytotaxonomical evidence that this species from Sumatra is a
sibling species differing from S. eximium from Java.
Further morphotaxonomic studies on the species statusof this species are now in progress.
Two immature larvae were infected with microsporidians and fungi, respectively.
22

A SUM M ARIZED LIST OF BLACK‑FLY SPECIES IN
SUM ATRA
The 22 black‑fly species identified in this survey
were further placed in the species‑groups within eachsubgenus, as follows. The four species previously
known from Sumatra and not collected in this survey(shown by an asterix) were also included in this list.
Genus Simulium Latreille
Subgenus Gomphostilbia Enderleinbatoense species‑group
１．S. cheongi
２．S. duolongum
３．S. friederichsi
４．S. flavocinctum
５．S. whartoni
６．S. padangense
７．S. parahiyangum
８．S. sundaicum
９．S. zonatum
ceylonicum species‑group
10．S. gyorkosae
11．S. sheilae
varicorne species‑group
12．S. varicorne
Subgenus Nevermannia Enderlein
feuerborni species‑group

13．S. feuerborni
ruficorne species‑group
14．S. aureohirtum
15．S. glatthaari
Subgenus Simulium Latreille s. str.
eximium species‑group
16．S. sp. nr. eximium
melanopus species‑group
17．S. bishopi
18．S. iridescens
multistriatum species‑group
19．S. fenestratum
nobile species‑group
20．S. nobile
striatum species‑group
21．S. argyrocinctum
tuberosum species‑group
22．S. brevipar
23．S. tani
unplaced speices
24．S. minangkabaum
25．S. nebulicola
26．S. sumatraense

ACKNOWLEDGEM ENTS
We are grateful to Dr. D.M. Davies, Professor
Emeritus, M cM aster University, Ontario, Canada, forreading the manuscript and giving valuable suggestions.
This study was supported by Indonesian Institute of
Sciences (LIPI) and by the M inistry of Education,
Science and Culture,Japan (grant no.03041065 to Prof.
I. M iyagi, and no. 11670246 to H. Takaoka).

REFERENCES
１) Crosskey, R.W. (1967): The classification of Simulium
Latreille (Diptera: Simuliidae) from Australia, New
Guinea and the Western Pacific. J.Natur.Hist.,1,23‑51
２) Crosskey, R.W. (1969 ): A re‑classification of the
Simuliidae (Diptera)of Africa and its islands. Bull.Br.
Mus. (Natur. Hist.)(Entomol.) Suppl. 14, 1‑195
３) Crosskey, R.W. (1973): Family Simuliidae. p. 423‑430.
In:Delfinado, M .D. and Hardy, D.E. eds., A catalog of
the Diptera of the Oriental Region. Vol. I. Suborder
Nematocera. University Press of Hawaii, 618p.
４) Crosskey, R.W. (1990): The natural history of blackflies. ix＋711p., John Wiley & Sons, Chichester, UK.
５) De Meijere, J.C.H. (1907): Studien uber Sudostasiatische Dipteren I. Tijdschr. Ent. 50, 196‑264
６) De Meijere, J.C.H. (1913): Studien uber Sudostasiatische Dipteren VII. Tijdschr. Ent. 56, 317‑354

166７) Edwards, F.W. (1925): Diptera Nematocera from theDutch East Indies. Treubia, 6, 154‑172
８) Edwards, F.W. (1934): The Simuliidae (Diptera) ofJava and Sumatra. Arch.Hydrobiol.13 Suppl.(“Tropische Binnengewusser”5, 92‑138
９) Hadi, U.K., Takaoka, H., Kondo, K., Hirai, H. (1996):
Larval polytene chromosomes of Simulium (Simulium)
eximium (Diptera:Simuliidae) from Java and Sumatra,Indonesia, with implication of sibling speciation. M ed.
Entomol. Zool., 47, 139 ‑144
10) Kuvangikadilok, C., Boomkemtong, C. and Phayuhasena, S. (1999 ): C‑banding in polytene chromosomesof six Simulium species (Diptera:Simuliidae) from Doi
Inthanon National Park,northern Thailand. J.Sci.Soc.
Thailand, 24, 215‑230
11) Takaoka H.(1977): Studies on black flies of the Nansei
Islands,Japan (Simuliidae,Diptera)I.On six species ofthe subgenus Eusimulium Roubaud, with the descriptions of Simulium (E.) satsumense sp. nov. and S. (E.)
subcostatum koshikiense ssp. nov. Jpn. J.Sanit.Zool.,27,
163‑180
12) Takaoka,H. (1979 ): The black flies of Taiwan (Diptera:Simuliidae). Pacific Insects, 20, 365‑403
13) Takaoka,H.(1983): Theblackflies (Diptera:Simuliidae)of the Philippines. xi＋199p., Japan Society for the
Promotion of Science, Tokyo
14) Takaoka, H. (1989 ): Further observations on the
autogeny of Simulium aureohirtum Brunetti (Diptera:
Simuliidae) in the Ryukyu Islands. Jpn. J. Sanit. Zool.,
40, 21‑28

15) Takaoka, H. (1991): A revisionary note on the black
fly, hitherto called “Simulium (Gomphostilbia) batoense
Edwards, 1934”from the Ryukyu Islands,Japan (Diptera:Simuliidae). Jpn. J. Trop. Med. Hyg., 19, 265‑273
16) Takaoka H. (1996): The geographical distribution of
the genus Simulium Latreille in the Oriental and Australasian Regions. Jpn. J. Trop. M ed.Hyg.,24,113‑124
17) Takaoka,H.and Davies,D.M .(1995a): A new black fly
species of Simulium (Nevermannia) from Sumatra, Indonesia. Jpn. J. Trop. Med. Hyg., 23, 127‑131
18) Takaoka,H.and Davies,D.M . (1995b): The black flies(Diptera: Simuliidae) of West Malaysia. viii＋175p.,
Kyushu University Press, Fukuoka19) Takaoka, H. and Davies, D.M . (1996): The black flies(Diptera: Simuliidae) of Java, Indonesia. viii＋81p.,
Bishop M us. Bul. Entomol. 6, Bishop M useum Press,
Hawaii20) Takaoka, H. and Saito, K. (1996): A new species andnew records of black flies (Diptera: Simuliidae) fromThailand. Jpn. J. Trop. Med. Hyg., 24, 163‑169
21) Takaoka, H. and Sigit, S.H. (1992): A new blackfly
species of Simulium (Gomphostilbia) from Java, Indonesia (Diptera:Simuliidae). Jpn.J.Trop.Med.Hyg.,
20, 135‑142
22) Takaoka, H. and Sigit, S.H. (1997): Three new black
fly species of Simulium (Diptera: Simuliidae) from
Sumatra, Indonesia. Jpn. J. Trop. M ed. Hyg., 25, 69 ‑80
23) Takaoka, H. and Suzuki, H. (1984): The blackflies(Diptera: Simuliidae) from Thailand. Jpn. J. Sanit.
Zool., 35, 7‑45

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Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 167‑175

TAXONOMIC NOTES ON SIMULIIDAE (DIPTERA)FROM THAILAND:DESCRIPTION OF A NEW SPECIESAND NEW DISTRIBUTIONAL RECORDS OF
NINE KNOWN SPECIESCHALIOW KUVANGKADILOK AND HIROYUKI TAKAOKA
Received April 3, 2000/Accepted June 21, 2000

Abstract: Simulium (Gomphostilbia) chumpornense sp. nov. is described from reared adults, pupae andmature larvae collected from southern Thailand. This new species is assigned to the varicorne species‑groupwithin the subgenus Gomphostilbia by having the adult antennae composed of 2＋8 segments in place of usual
2＋9 segments. In addition, nine known simuliid species, most of which were described from Peninsular
M alaysia,are recorded for the first time from Thailand,bringing the total number of simuliid species in thiscountry to 40.
Key words: Simuliidae, black fly, Thailand, new species, fauna

Since Takaoka and Suzuki (1984) reported 19
black‑fly species (Diptera:Simuliidae) from Thailand,
seven more species were added (Takaoka and Saito,
1996;Takaoka and Adler,1997),totaling the number ofsimuliid species from this country to 26 consisting of 22
named and four unnamed species.
In 1996‑1999, one of us (CK) made faunistic andecological surveys on Simuliidae in various provinces ofThailand,and collected many species including five new
species, nine newly recorded ones, and two unnamed
ones (i.e., Simulium sp. A and S. sp. B, sensu Takaoka
and Suzuki, 1984). In our recent cytogenetic papers(Kuvangkadilok et al., 1998, 1999a, 1999b), we haveapplied two Malaysian known species names, i.e., S.
caudisclerum and S. feuerborni, for S. sp.A and S. sp.B,
respectively. In addition, we have already describedfour of the five new black‑fly species, of which threewere assigned to the subgenus Simulium s. str. and theone remained unplaced in any subgenera (Takaoka andKuvangkadilok, 1999 ).
We herein describe the remaining one new species
which apparentlybelongs to the subgenus Gomphostilbia,
and give brief notes on the nine known species whichwere newly recorded from Thailand.
The morphological features and terms used herein
follow mostly those of Crosskey (1969 ), and partially１２those of Takaoka (1983). All type specimens of a new
species will be deposited in the Department of Biology,
Faculty of Science, Mahidol University, Bangkok,
Thailand.

DESCRIPTION OF NEW SPECIES()
and Kuvangkadilok sp. nov.

Takaoka

Female. Bodylength 1.8 mm.
. As wide as thorax.
Frons (Fig.1)brownish black,dull,moderately covered
with yellowish white, scale‑like, recumbent hairs (Fig.
2) (except median longitudinal portion narrowly bareon upper 1/2), and with 1 dark hair on upper part ofright side;lower narrow juncture to clypeus also fully
covered with yellowish white, scale‑like, recumbent
hairs; frontal ratio 1.5:1.0:1.7; frons‑head ratio 1.0:4.0.
Fronto‑ocular area (Fig. 3) well developed, narrow.
Clypeus brownish black, dull, densely covered withyellowish white, scale‑like, recumbent hairs interspersed with several dark hairs along each lateral margin.
Antenna (Fig. 4) composed of 2＋8 segments, apicalflagellar segments compressed dorsoventrally; scape,pedicel, 2nd and 4th flagellar segments entirely yellow,
and 1st and 3rd flagellar segments light or medium

Department of Biology, Faculty of Science, M ahidol University, Rama VI Road, Bangkok 10400, Thailand
Department of Infectious Disease Control, Oita Medical University, Hasama, Oita 879‑5593, Japan ＊:Correspondent author

168

brown except base of 1st flagellar segment yellow, and5th to 8th flagellar segments brownish black. Maxillary
palp composed of 5 segments,light brown,proportional
lengths of 3rd, 4th and 5th segments 1.0:1.2:2.5, 3rdsegment (Fig. 5) widened distally;sensory vesicle (Fig.
5) of moderate size,nearly ellipsoidal,0.36× as long as
3rd segment, with medium opening. Maxillary laciniawith 9 inner teeth and 13 or 14 outer teeth. Mandiblewith 22‑24 small inner teeth and lacking outer ones.
Cibarium (Fig.6) with a pair of triangular,well sclerotized projections at posterior margin;any processes or
tubercles absent.
. Scutum brownish black withanterolateral calli somewhat paler, subshiny, thinly
white pruinose,with 3 dark longitudinal vittae (1 medialand 2 submedial),densely covered with yellowish white,scale‑like, recumbent hairs, interspersed with dark,
similar hairs; scutellum brownish black, covered withshort, yellowish white, scale‑like hairs as well as long,
upright, dark hairs along posterior margin. Postscutellum brownish black, bare. Pleural membrane bare.
Katepisternum brownish black, longer than deep, withfine, short, yellowish white hairs.
. Foreleg:coxa
and trochanter pale yellowish white;femur dark grey;
tibia pale yellowish white, with basal knee black, andwith subbasal and subapical dark grey bands; tarsus
brownish black with basal knee of basitarsus yellow,
with sparse dorsal hair crest;basitarsus nearly cylindrical,ca.5.9 × as long as its greatest width. Midleg:coxa
brownish black;trochanter pale yellowish white;femur
dark grey with apex paler;tibia pale yellowish white on
basal 2/5 with dark grey or light brown subbasal band,and medium brown on distal 3/5;tarsus light to medium
brown with basal 2/3 of basitarsus, and base of 2nd
tarsal segment yellowish white. Hind leg (Fig.7):coxa
medium brown, trochanter pale yellowish white;femur
light brown with base pale yellowish white and apicalcap medium brown;tibia yellowish white on basal 2/3
with dark grey subbasal band, and brownish black on
distal 1/3;tibia much angulate posteriorly at distal 1/3
and also at basal 1/3 when viewed laterally; tarsus
brownish black except basal 2/3 or a little more ofbasitarsus, basal 1/2 of 2nd tarsal segment,and base of
3rd tarsal segment yellowish white;basitarsus narrow,nearly parallel‑sided, ca. 6.5× as long as wide, and ca.
0.50× and ca. 0.48× as wide as greatest width of tibia
and femur, respectively; calcipala ca. 1.3× as long as
wide, and ca. 0.6× as wide as distal portion of basitarsus. All femora, tibia and parts of tarsus densely covered with pale or dark,scale‑like hairs. Claws (Fig.8)
each with large basal tooth, 0.5× as long as claw.
. Length 1.6 mm. Costa with dark spinules as well

as dark hairs except basal hair tuft pale. Subcosta
almost bare. Hair tuft on stem vein pale. Basal portionof radius fully haired.
. Basal scale lightbrown, with fringe of pale hairs. Abdomen brownish
black except base of 2nd segment somewhat paler,sparsely or moderately covered with short yellowish
white hairs, intermixed with dark hairs; tergites ofsegments 2, 6, 7 and 8 shiny;sternal plate on segment 7(Figs. 9 and 10). Sternite 8
undeveloped.
bare medially, with 10‑12 long hairs and a few shorthairs on each side. Anterior gonapophyses nearly triangular, thin, membraneous, covered densely with microsetae (though posteromedial corner somewhat widely bare), interspersed with 2‑4 short setae; inner margins narrowly sclerotized, moderately separated fromeach other. Genital fork of usual inverted‑Y form;arms
slender, folded medially, forming a distinct projection
directed forward.
Paraproct somewhat produced
ventrally, with 16‑18 long hairs on outer surface, andwith 3 sensilla on inside surface. Cercus ca.0.5× as longas wide,rounded posteriorly. Spermatheca oblong,ca.1.
8× as long as wide, well sclerotized, even near tubal
juncture, with several internal setae.
Male. Body length probably 2.0 mm.
. Lost.
. Scutum brownish black, shiny, whitish grey‑
pruinose except central large area unpruinose, densely
covered with yellow, scale‑like, recumbent hairs, interspersed with dark ones. Scutellum brownish black,covered with yellow, scale‑like, short hairs and several
dark hairs near posterior margin. Postscutellum brownish black,bare. Pleural membrane bare. Katepisternum
as in female.
. Colorings and shapes as in female
except relative sizes as follows:fore basitarsus ca.6.2×
as long as greatest width;hind basitarsus (Fig. 11) ca.
6.1× as long as wide, and ca. 0.55× and ca. 0.51× as
wide as greatest width of tibia and femur,respectively.
Calcipala ca.1.2× as long as wide.
. As in female.
. Basal scale light brown, with fringe of palehairs. Dorsal surface of abdomen brownish black
except basal 3/4 of 2nd segment yellow to light brown,covered with dark hairs;segments 2,5,6 and 7 each witha pair of shiny dorsolateral patches,those on segment 2
silvery iridescent in certain angles of light.
(Figs. 12‑16). Coxite in ventral view, subquadrate, ca.
1.5× as long as wide. Style ca.0.85× as long as coxite,
gradually tapered toward apex, curved inward, withapical spine. Ventral plate transverse, densely covered
with microsetae on most area of ventral surface andcentral area of posterior surface; basal arms directed
forward, expanded laterally and dorsally near base.

169

Figures 1‑16 Morphological characters of S. chumpornense sp.nov.1‑10,female,and 11‑16,male. 1,frons;2,scale‑like hairs
on frons; 3, fronto‑ocular area; 4, antenna; 5, 3rd segment of maxillary palp with sensory vesicle inside; 6,cibarium; 7, hind leg; 8, claw of hind leg; 9, genitalia in situ (ventral view), showing 8th sternite, anterior
gonapophyses,genital fork,paraprocts,cerci and spermatheca;10,paraproct and cercus (lateral view);11,hindbasitarsus and 2nd tarsal segment;12,genitalia in situ (ventral view)showing coxites,styles,and ventral plate;13,right style (medial view);14,ventral plate (end view);15,left paramere (end view);16,median sclerite (endview). Scale bars;0.1 mm for figs.4,7 and 11;0.05 mm for figs.1 and 3;0.03 mm for figs.5,6,9,10,12‑16;0.01
mm for figs. 2 and 8.

170

Figures 17‑23 Morphological characters of S. chumpornense sp. nov. 17 and 18, pupa, and 19‑23, larva. 17, left gill filaments(dorsal view);18, basal 1/3 of right gill and interspiracular trunk (lateral view) showing an arrangement offilaments;19,apical portion of mandible;20,hypostomium (bristles omitted);21,ventral surface of head capsuleshowing hypostomium and postgenal cleft;22,various setae on dorsal surface ofabdomen;23,anal sclerite. Scalebars:0.2 mm for fig. 17;0.1 mm for fig. 18;0.05 mm for figs. 21 and 23;0.03 mm for fig.20;0.01 mm for figs.19
and 22.

Parameres of moderate size,each with 3 long hooks andseveral short incomplete ones. Median sclerite thin,plate‑like, wide, with apex rounded. Cerci small,rounded, each with 10 or 11 short hairs.
Pupa. Body length 2.0 mm.
. Integument yellowish brown, moderately or somewhat sparsely covered
with round tubercles;antennal sheath normal, with no
spinous projections,and almost bare;face with 1 pair ofsimple,long trichomes with coiled or uncoiled apex,andfrons with 3 pairs of simple, long trichomes with uncoiled apex; 3 frontal trichomes on each side arisingclose together, subequal in length to one another andalso to facial one.
. Integument yellowish

brown,moderately covered with round tubercles,with 3
pairs of simple,long trichomes dorsally,with 2 pairs of
simple, long trichomes anterolaterally, with 1 pair ofsimple, medium trichomes posterolaterally, and with 3
pairs of simple,medium trichomes ventrolaterally. Gill
(Figs. 17 and 18) composed of 8 slender filaments,withsomewhat swollen,transparent organ ventrally at base;gill divided vertically near base into 2 main stout filaments, of which upper one is much thicker than lower
one, and with 5 slender filaments each arising independently from its dorsal or outer surface;lower main stout
filament further divided into 2 slender filaments, ofwhich outer one is somewhat thinner at least nearbifurcation than the inner one;all filaments light yellow-

171

ish brown, subequal in length to one another (1.2‑1.6mm), slightly tapered toward apical tips;cuticular surface of filaments with distinct annular ridges and furrows graduallybecoming indistinct apically,and densely
covered with minute tubercles;annular ridges on basal
portion of upper and lower main filaments very distinct
forming reticulate pattern, with relatively larger tubercles on ridges and smaller ones on interridges.
. Terga 1 and 2 pale yellow,almost bare;tergum 1
with 1 simple, slender seta on each side;tergum 2 with
1 simple, slender, short seta and 5 short, somewhat
spinous setae, submedially on each side;terga 3 and 4
pale, each with 4 hooked spines and 1 short, somewhat
spinous seta on each side;tergum 5 lacking spine‑combs;
terga 6‑9 each with distinct spine‑combs in transverse
row,together with comb‑like groups of minute spines oneach side; tergum 9 with a pair of distinct, conicalterminal hooks,which have round apex. Sternum 4 with
1 simple hook (slightly smaller in size than those onsternum 7) and a few simple, slender, minute setae oneach side; sternum 5 with a pair of bifid hooks submedially on each side;sterna 6 and 7 each with a pair ofbifid inner and simple or bifid outer hooks somewhat
spaced from each other,and a few,simple,short,slender
minute setae on each side. Each side of segment 9 with
3 grapnel‑like hooklets.
. Simple,wall‑pocket‑
shaped, neatly and compactly woven without open
spaces in webs, moderately extending ventrolaterally;
anterior margin somewhat thickly woven;posterior 1/2
with floor roughly woven;individual threads indistinct;
2.8 mm long × 1.5‑1.8 mm wide.
Mature larva. Body length 3.8‑4.0 mm. Body paleyellowish, with dark greyish transverse band on 1st
thoracic segment and on each abdominal segment.
Cephalic apotome pale yellow,moderately covered withshort colorless setae; head spots indistinct. Antenna
with 3 segments (of subequal length) and apical sensillum,longer than stem of labral fan. Labral fan with 28‑
31 main rays. Mandible (Fig. 19 ) with comb‑teeth
decreasing in size from 1st to 3rd;mandibular serrationconsisting of 2 teeth (1 large and 1 small);large tooth
directed anteroventrally,making an acute angle distallywith ventral margin of mandible. Hypostomium (Fig.
20) with an anterior row of 9 teeth, of which median
tooth subequal in length to each corner tooth,and longer
than 3 intermediate teeth on each side; lateral margin
with 1 tooth or 2;hypostomal bristles 3 or 4 in number,slightly diverging posteriorly from lateral margin oneach side. Postgenal cleft (Fig. 21) very deep, leaving
narrow bridge. Thoracic segment 3 with 2 pairs (dorsal

and dorsolateral) of conical protuberances; thoracic
cuticle sparsely covered with simple,bifid or trifid setae(similar to those on abdomen) on dorsal surface.
Abdominal segments 1‑5 each with 2 pairs (dorsal anddorsolateral) of conical protuberances, of which dorsal
pair is somewhat more prominent; abdominal cuticle
covered dorsally and dorsolaterally with simple, bifid,
trifid and quadrifid setae (Fig.22)sparsely on segments
1‑4, and moderately on segments 5‑8; last segment
moderately covered with simple and bifid setae on eachside of anal sclerite. Rectal gill compound, each of 3
lobes with 8 finger‑like secondary lobules. Anal sclerite(Fig.23)X‑shaped,with anterior arms ca.0.8× as longas posterior ones. Accessory sclerite absent. Ventral
papillae well developed, conical in shape. Posterior
circlet with ca. 60 rows of up to 11 hooklets per row.
TYPE SPECIMENS. Holotype:female, reared from pupa,
collected from Ka Po Waterfall (altitude 40 m),
Chumporn Province,southern Thailand,4.Ⅵ.1999,by C.
Kuvangkadilok and C. Boonkemtong. Paratypes: 1
male, reared from pupa, 2 pupae, and 39 larvae, samedata as holotype.
ECOLOGICAL NOTES. The pupae and larvae of this new
species were collected from trailing grasses in a stream,
5‑6 m wide,together with S. nobile. The water temperature and acidity of the stream were 26°
C and pH 9.3,
respectively.
ETYMOLOGY. The species chumpornense refers to theprovince, Chumporn, where this species was collected.
REMARKS. This new species is assigned to the varicorne
species‑group within the subgenus Gomphostilbia,
defined by Takaoka and Davies (1996), by having theantenna with 2＋8 segments in place of the usual 2＋9
segments.
The pupa of S. chumpornense is characterized by
the arrangement of the eight gill filaments,as shown in
Figs. 17 and 18. All the four known speices of thevaricorne species‑group,i.e.,S. varicorne Edwards fromIndonesia and Peninsular M alaysia,S. shogakii Rubtsov
from Japan,Korea,and China,S. burtoni Takaoka andDavies, and S. novemarticulatum Takaoka and Davies,
both from Peninsular Malaysia, have the ordinaryarrangement of eight gill filaments (i.e., 3＋3＋2 filaments) (Bentinck, 1955; Takaoka and Davies, 1995;
unpublished data). However S. chumpornense seems to
be most closely related to S. varicorne since the pupal
gill of the latter species is first divided into two rather

172

stout filaments near its base, as in S. chumpornense.
The adults of S. chumpornense are easily separated
from S. novemarticulatum by the antenna consisting of
2＋8 segments (c.f.,2＋7 segments in the latter). Amongthe other three related species which have 2＋8 antennal
segments, this new species seems to be more closely
related to S. varicorne than to S. burtoni and S. shogakiiby having the similar flat ventral plate in the male
genitalia. The ventral plates of the latter two species
are produced ventrally near its posterior margin(Bentinck, 1955;Takaoka and Davies, 1995).
The female of S. chumpornense is easily distinguished from S. shogakii by having the ellipsoidal sensory vesicle (Fig. 5)｛c.f., globular in the latter according to Bentinck (1955)｝, and from S. burtoni by having
the different color pattern of the antenna (Fig. 4). In
the antenna of S. burtoni, first and second flagellar
segments are dark yellow, and third to eighth ones aredark brown, though most of the inside surface of the
fourth segment is yellowish (Takaoka and Davies,
1995). The female of S. varicorne has not been known
as yet.

NOTES ON NEWLY RECORDED SPECIES()
Takaokaand Davies, 1995
Simulium (Gomphostilbia) angulistylum Takaoka
and Davies, 1995:42‑46 (female, male, pupa andlarva).
SPECIMENS EXAM INED. 30 larvae, Haew Suwat Waterfall (altitude 630 m),Khao Yai National Park,Nakorn
Ratchasima Province,northeastern Thailand,10.Ⅵ.1998,
by C. Kuvangkadilok and C. Boonkemtong;1 female, 2males and 25 larvae, Huai Yang Waterfall (altitude 75m),Prachuap Kirikuan Province,central Thailand,4.Ⅵ.
1999, by C. Kuvangkadilok and C. Boonkemtong; 25
larvae, Sa Nangmanora Waterfall (altitude 150 m), Sa
Nangmanora Forest, Park, Phangnga Province, southern Thailand, 3.Ⅶ.1999, by C. Kuvangkadilok and C.
Boonkemtong;1 male,2 pupae and 78 larvae,Khao Phra
Narai Waterfall (altitude 120 m), Ranong Province,
southern Thailand, 4.Ⅶ.1999, by C. Kuvangkadilok andC.Boonkemtong;1 female,1 male and 29 larvae,Muang
Tuad Waterfall (100 m), Tai Rom Yen National Park,
Suratthani Province,southern Thailand,3.Ⅷ.1999,by C.
Kuvangkadilok and C. Boonkemtong; 2 pupae and 23
larvae, Ngao Waterfall (altitude 50 m), Ranong Province,southern Thailand,4.Ⅶ.1999,by C.Kuvangkadilok
and C. Boonkemtong; 2 pupae, Huai Luang Waterfall(altitude 300 m), Phu‑Jong Na‑Yoy National Park,
Ubon Ratchathani Province, northeastern Thailand, 16.
.1998, by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The larvae and pupae of thisspecies were collected from fallen leaves and/or trailing
grasses in several streams of various widths 0.5‑5.0 m.
The water temperature and acidity of the streams were24.0‑26.5°
C and pH 7.6‑9.4, respectively. This species
was collected together with S. grossifilum, S. nakhonense, S. nobile, S. parahiyangum, S. quinquestriatum, S.
sheilae, S. siamense, and S. tani.
REMARKS. S. angulistylum was originally describedfrom Peninsular Malaysia (Takaoka and Davies,1995).
This species is characterized by the eight short slender
pupal gill filaments and the male genitalia with anabruptly‑bent style and a posteriorly‑attenuated ventral
plate. The Thai specimens are in good agreement at allstages with the original descriptions.
()
Takaoka andDavies, 1995
Simulium (Gomphostilbia) sheilae Takaoka andDavies, 1995: 60‑65 (female, male, pupa andlarva).
SPECIMENS EXAMINED. 1 male, 4 pupae and 255 larvae,
Boripat Waterfall (altitude 50 m),ThalayBun National
Park, Songkhla Province, southern Thailand, 1.Ⅵ.1999,
by C.Kuvangkadilok and C.Boonkemtong;3 females,1male, 6 pupae and 32 larvae, Tone Phrew Waterfall(altitude 125 m), Khao Bun Tad Wildlife Sanctuary,
Trang Province, southern Thailand, 2.Ⅵ.1999, by C.
Kuvangkadilok and C. Boonkemtong: 1 male, Huai
Yang Waterfall (altitude 75 m), Prachuap Kirikuan
Province, western Thailand, 4.Ⅵ.1999, by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The pupae and larvae of thisspecies were collected from fallen leaves and/or small
plant roots in several streams 0.5‑3.0 m wide. The
water temperature and acidity of the streams were 24‑
26°
C, and pH 7.0‑8.4, respectively. This species wascollected together with S. fenestratum, S. grossifilum, S.
nakhonense and S. tani.
REMARKS. S. sheilae was originally described from
Peninsular Malaysia, and was assigned to the
ceylonicum species‑group by Takaoka and Davies(1995). This species is separated from other related

173

species of the same group by the enlarged oblong female
sensory vesicle (ca. 0.7 times as long as 3rd maxillarypalpal segment) and the almost brown male hindbasitarsus (though basal 1/3 or a little less somewhat
paler). The reared adult female and male specimens,aswell as pupal and larval ones examined in this study,aremorphologically almost the same as those originallydescribed.
()
Takaokaand Davies, 1995
Simulium (Gomphostilbia) dentistylum Takaoka
and Davies, 1995:51‑55 (male, pupa and larva).
SPECIMENS EXAM INED. 1 male reared from pupa, Huai
Luang Waterfall (altitude 300 m), Phu‑Jong Na‑Yoy
National Park, Ubon Ratchathani Province, northeastern Thailand, 16. .1998, by C. Kuvangkadilok and C.
Boonkemtong;1 pupa,Yong Waterfall (altitude 120 m),
Nakorn Srithammarat Province,southern Thailand,19.
Ⅳ.1999, by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The pupae of this species werecollected from fallen leaves in streams 1.0‑5.0 m wide.
The water temperature and acidity of the streams were24.0‑26.0°
C and pH 7.4‑7.5, respectively. This species
was collected together with S.asakoae,S.chainarongi,S.
nakhonense, S. nodosum, S. parahiyangum, S. siamense
and S. tani.
REMARKS. S. dentistylum was originally described from
Peninsular Malaysia (Takaoka and Davies,1995). This
species is very similar to S. parahiyangum by having theeight short veryslender pupal gill filaments on each side,and the verydeep larval postgenal cleft,but differs fromthe latter by the arrangement of the pupal gill,the fewer
tubercles on each round ridge of the pupal antennal
sheaths,and the absence of the dorsal protuberances on
the larval abdomen. The two pupae and one reared
adult male from Thailand agree well morphologicallywith the original descriptions.
()
Takaokaand Davies, 1995
Simulium (Morops) gombakense Takaoka andDavies, 1995:82‑84 (larva).
Simulium (Gomphostilbia) gombakense: Takaoka,
2000: (male and pupa).
SPECIMENS EXAMINED. 18 larvae,M ae Klang Waterfall(altitude 940 m), Doi Inthanon National Park, Chiang

Mai Province, northern Thailand, 18.V.1997, by C.
Kuvangkadilok,S.Phayuhasena and C.Boonkemtong;1
female reared from pupa, Riang Thong Waterfall (175m in altitude), Khao‑Pu Khao‑Ya National Park,
Pattalung Province,southern Thailand. 2.Ⅵ.1999,by C.
Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The pupa and larvae of this species
were collected from fallen leaves in two streams 0.5 m
and 1.0‑2.0 m wide, respectively. The water temperature and acidity were 25.5°
C and pH 8.4 in one stream,and 26.0°
C and pH 9.4 in the other. This species wascollected together with S. asakoae and S. tani or with S.
nakhonense.
REMARKS. This species was originally described frompharate pupal and larval specimens from Peninsular
Malaysia and was tentatively assigned to the subgenus
Morops (Takaoka and Davies, 1995). However, it wastransferred to the subgenus Gomphostilbia when its adultmale reared from a pupa was obtained and studied(Takaoka,2000). The pupa of this species is characterized byits gill of much inflated form with six finger‑likeprojections and with eight slender thread‑like filaments(Takaoka, 2000). The pupa and larvae collected fromThailand agree well morphologically with the redescriptions (Takaoka, 2000).
()
Takaoka andDavies, 1995
Simulium (Simulium) grossifilum Takaoka andDavies, 1995: 105‑110 (female, male, pupa andlarva).
SPECIMENS EXAMINED. 1 male reared from pupa, and 8
larvae, Muang Tuad Waterfall (100 m in altitude),Tai
Rom Yen National Park, Nakorn Srithammarat Province,southern Thailand,3.Ⅵ.1999,by C.Kuvangkadilok
and C. Boonkemtong;56 larvae, Ngao Waterfall (altitude 50 m), Ranong Province, southern Thailand, 4.Ⅷ.
1999, by C. Kuvangkadilok and C. Boonkemtong; 1
female reared from pupa and 1 pupa and 3 larvae,Mae
Yai Waterfall (100 m in altitude), Khao Sok National
Park,Suratthani Province,southern Thailand,2.Ⅷ.1999,
by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The pupae and larvae of thisspecies were collected from trailing grasses and fallen
leaves in streams 0.5‑2.0 m wide. The water temperature and acidity of the streams were 24.8‑26.0°
C,and pH
8.0‑8.3, respectively.
This species was collected

174

together with S. angulistylum, S. asakoae, S. decuplum,S.
malayense, S. nakhonense, S. parahiyangum, S. quinquestriatum, S. tani and S. yongi.
REMARKS. S. grossifilum was originally described from
Peninsular Malaysia,and was assigned to the griseifrons
species‑group (Takaoka and Davies, 1995). This
species is verydistinctive among the subgenus Simuliums. str. by its swollen pupal gill filaments covered withminute setae, the female anterior gonapophyses with adorsal projection, and the male lamellate ventral plate.
The female, male, pupal and larval specimens collectedfrom Thailand are morphologically in good agreementwith the original descriptions.
()
Takaoka andDavies, 1995
Simulium (Simulium) malayense Takaoka andDavies, 1995:120‑123 (female, pupa and larva).
SPECIMENS EXAMINED. 1 male reared from pupa, Mae
Yai Waterfall (altitude 100 m), Khao Sok National
Park,Suratthani Province,southern Thailand,2.Ⅷ.1999,
by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The one pupa of this species wascollected from a fallen leaf in a small stream 1 m wide.
This species was collected together with S. grossifilum
and S. yongi.
REMARKS. S. malayense was described from female,
pupal and larval specimens collected from Peninsular
Malaysia, and was assigned to the multistriatum
species‑group (Takaoka and Davies, 1995). This
species is easilyseparated from the other related speciesof the same group by its simple wall‑pocket‑shaped
cocoon without anterolateral windows. M orphologicalcharacters of the pupa collected from Thailand arealmost the same as those in the original description.
()
de Meijere, 1907
Simulium nobile de Meijere, 1907: 206 (male);
Edwards, 1934: 115 (female, male, pupa andlarva).
Simulium (Simulium) nobile: Crosskey, 1973: 428;
Crosskey, 1988: 475; Takaoka and Davies, 1995:
123;Takaoka and Davies,1996:61 (female,male,pupa and larva).
SPECIMENS EXAM INED. 8 females,6 males,60 pupae andca. 700 larvae, Ka Po Waterfall (altitude 40 m),

Chumporn Province,southern Thailand,5.Ⅶ.1999,by C.
Kuvangkadilok and C. Boonkemtong;6 pupae and 114
larvae, Sa Nangmanora Waterfall (altitude 50 m), Sa
Nangmanora Forest Park,Phangnga Province,southern
Thailand, 3.Ⅶ.1999, by C. Kuvangkadilok and C. Boonkemtong;7 females, 5 males, 85 pupae and 833 larvae,
Tone Sai Waterfall (altitude 30 m), Phuket Province,
southern Thailand, 2.Ⅷ.1999, by C. Kuvangkadilok and
S. Phayuhasena.
ECOLOGICAL NOTES. The pupae and larvae of thisspecies were collected from fallen leaves in streams 1.0‑
3.0 m wide. The water temperature and acidity were25.0‑27.0°
C, and pH 7.8‑9.4, respectively. This species
was collected together with S. angulistylum, S. chumpornense, S. nakhonense and S. siamense.
REMARKS. S. nobile was originally described from Java(de M eijere, 1907), and later recorded from South
Sumatra (Edwards, 1934), Peninsular Malaysia andSabah (Crosskey, 1973). This species is a type speciesof the nobile species‑group,and is readily distinguished,by its six short slender pupal gill filaments, from S.
nodosum, the only species of the same group so far
known from Thailand. The Thai specimens examinedin this study are morphologically almost the same as theJavanese specimens redescribed byTakaoka and Davies(1996).
()
Takaoka and Davies,
1995
Simulium (Simulium) rudnicki Takaoka andDavies, 1995:155‑157 (female).
SPECIMENS EXAMINED. 20 pupae and 216 larvae,M ae Ya
Waterfall (altitude 520 m),Doi Inthanon National Park,
Chiang Mai Province, northern Thailand, 21.Ⅷ.1996, by
C. Kuvangkadilok, S. Phayuhasena and C. Boonkemtong: 83 larvae, Vachiratharn Waterfall (altitude
700 m), Doi Inthanon National Park,Chiang Mai Province, northern Thailand, 15.Ⅱ.1997, by C. Kuvangkadilok, S. Phayuhasena and C. Boonkemtong; 13 larvae, Tad Deuan Waterfall (altitude 170 m), Srisatchanalai National Park, Sukothai Province, northern
Thailand, 26.I.1999, by C. Kuvangkadilok and C. Boonkemtong.
ECOLOGICAL NOTES. The pupae and larvae of thisspecies were collected from rock and stone surfaces instreams 1.0‑2.0 m wide. The water temperature andacidity of the streams were 16‑22°
C and pH 8.4‑9.0,

175respectively. This species was collected together with S.
nakhonense, S. quinquestriatum and S. siamense.
REMARKS. S. rudnicki was originally described only
from two females collected from Langkawi Island,
Malaysia, and remained ungrouped within Simulium s.
str. (Takaoka and Davies,1995). Two pharate females
dissected out of the pupae collected from Thailand
conform to the original description in most characters
including the yellowish leg colorings and the anterior
gonapophyses with a narrow transparent portion along
inner and posterior margins. The pupae collected fromThailand are not different from those of S. rudnicki
recently collected from Langkawi Island (unpublisheddata). They have six slender gill filaments on each side.
()
Takaoka and Davies,
1997
Simulium (Simulium) yongi Takaoka and Davies,
1997:11‑16 (female, male, pupa and larva).
SPECIMENS EXAMINED. 1 female reared from pupa,Mae
Yai Waterfall (altitude 100 m), Khao Sok National
Park,Suratthani Province,southern Thailand,2.Ⅷ.1999,
by C. Kuvangkadilok and S. Phayuhasena.
ECOLOGICAL NOTES. The only one pupa of this species
was collected from a fallen leaf in a small stream ca.1.0
m wide. This species was collected together with S.
grossifilum and S. malayense.
REMARKS. The reared female and its pupal exuvia
examined in this study agree well morphologically withthose originally described from Peninsular Malaysia by
Takaoka and Davies (1997). The female of this species
is very similar to S. rudnicki, but differs from the latterby the darker leg colorings.

ACKNOWLEDGEMENTS
This work was supported by the TRF/BIOTEC
Special Program for Biodiversity Research and Training grant BRT 139007 to CK,and in part bythe Grant‑in
Aid of Ministry of Education, Science and Culture,
Japan (no. 11670246) to HT.

REFERENCES
１) Bentinck, W. (1955): The black flies of Japan and
Korea (Diptera:Simuliidae),22 p.,406 M edical General
Laboratory U.S. Army, Tokyo.

２) Crosskey, R.W. (1969 ): A re‑classification of the
Simuliidae (Diptera)of Africa and its islands. Bull.Br.
Mus. (Natur. Hist.)(Entomol.) Suppl. 14, 1‑195
３) Crosskey, R.W. (1973): Family Simuliidae, p. 423‑30.
In:Delfinado, M.D. and Hardy, D.E., eds., A catalog of
the Diptera of the Oriental Region. Vol. I. Suborder
Nematocera. University Press of Hawaii, 618 p.
４) De Meijere, J.C.H. (1907): Studien uber Sudostasiatische Dipteren I. Tijdschr. Ent., 50, 196‑264 (Simuliidae
pp. 206‑7).
５) Edwards,F.W. (1934): Deutsche Limnologische Sunda‑
Expedition. The Simuliidae (Diptera) of Java andSumatra. Arch. Hydrobiol., 13 (Suppl. 5), 92‑138
６) Kuvangkadilok,C.,Boonkemtong,C.and Phayuhasena,
S. (1998): C‑banding in polytene chromosomes of six
Simulium species (Diptera:Simuliidae) from Doi Inthanon National Park, northern Thailand. J. Sci. Soc.
Thailand, 24, 215‑230
７) Kuvangkadilok, C., Phayuhasena, S. and Baimai, V.
(1999a): Population cytogenetic studies on Simulium
feuerborni Edwards (Diptera:Simuliidae)from northern
Thailand. Genome, 42, 80‑86
８) Kuvangkadilok, C.,Phayuhasena,S.and Boonkemtong,
C. (1999b): Larval polytene chromosomes of fivespecies of blackflies (Diptera: Simuliidae) from Doi
Inthanon National Park,northern Thailand. Cytologia,
64, 197‑207
９) Takaoka,H.(1983): Theblackflies (Diptera:Simuliidae)of the Philippines. xi＋199 p., Japan Society for the
Promotion of Science, Tokyo
10) Takaoka, H. (2000): Taxonomic notes on Simulium
gombakense (Diptera: Simuliidae) from Peninsular
Malaysia:descriptions of male and pupa,and subgenerictransfer from Morops to Gomphostilbia. Jpn. J. Trop.
Med. Hyg., 28, 111‑114
11) Takaoka, H. and Adler, P.H. (1997): A new subgenus,
Simulium (Daviesellum), and a new species, S. (D.)
courtneyi, (Diptera: Simuliidae) from Thailand andPeninsular Malaysia. Jpn.J.Trop.M ed.Hyg.,25,17‑27
12) Takaoka,H.and Davies,D.M . (1995): The Black Flies(Diptera: Simuliidae) of West M alaysia. viii＋175 p.,
Kyushu University Press, Fukuoka
13) Takaoka,H.and Davies,D.M . (1996): The Black Flies(Diptera: Simuliidae) of Java, Indonesia. viii＋81 p.,
Bishop Museum Bull. Entomol. 6., Honolulu
14) Takaoka, H. and Davies, D.M. (1997): Simulium(Simulium) yongi sp. nov. (Diptera: Simuliidae) from
Peninsular Malaysia. Jpn.J.Trop.M ed.Hyg.,25,11‑16
15) Takaoka, H. and Kuvangkadilok, C. (1999 ): Four new
species of black flies (Diptera: Simuliidae) fromThailand. Jpn. J. Trop. Med. Hyg., 27, 497‑509
16) Takaoka, H. and Saito, K. (1996): A new species andnew records of black flies (Diptera: Simuliidae) fromThailand. Jpn. J. Trop. Med. Hyg., 24, 163‑169
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Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 177‑181

ROLE OF ANOPHELES SUBPICTUS AS A PRIMARY VECTOR
OF MALARIA IN AN AREA IN INDIASOUMENDRANATH CHATTERJEE AND GOUTAM CHANDRA
Received September 13, 1999 /Accepted July 24, 2000

Abstract:Sibling species A of Anopheles subpictus (fresh water form)has been incriminated and established
as a primary vector of malaria for the first time in an area (Tarakeswar,West Bengal)in Indian subcontinent with a natural sporozoite (Plasmodium vivax) rate of 0.32% (2/621). M oderate anthropophilic index(41.0) and high survival rate per gonotrophic cycle (0.58) indicate its efficiency as vector. Coincidence of
higher malaria cases and higher density of An. subpictus in the study area is of high relevance. No natural
sporozoite infection was detected in other anophelines available like An. vagus, An. annularis and An.
barbirostris.
Key words:Anopheles subpictus, primary vector, malaria, India

INTRODUCTION
Anopheles subpictus Grassi is a recognised primary
vector of malaria in Australasian Zone (Russel et al.,1963),Celebes (Van Hell,1952)and in Portuguese timor(Ferreira and Breda, 1962) and a secondary vector in
Sri Lanka (Hearth et al., 1983). The role of An.
subpictus as a vector of malaria in India is obscure. The
existence of two sibling species of An. subpictus namely,
species A (fresh water form) and species B (brakishwater form) have been described in India (Suguna,1982). Sibling species B has been incriminated as avector in some coastal areas of South India (Russel andJacob,1939,Russel and Rao,1940;Panicker et al.,1981)
and An. subpictus (sibling species not defined)has been
incriminated in Central India with very low sporozoite
rate (0.02%) in the presence of other recognised primary vector (Kulkarni, 1983). Present study has been
performed in Tarakeswar area of West Bengal, India(175 km away from Bay of Bengal). According to data
recorded in Tarakeswar Block Hospital average annual
incidence of Plasmodium vivax and P. falciparum was
962 and 65, respectively for the last ten years (1988‑
1997) where the total population was 70,000, seventynine percent of the cases were recorded during monsoon
months (Jul.‑Oct.).

M ATERIALS AND M ETHODS
Indoor resting mosquitoes were collected by aspir-ators (WHO,1964)from fixed 5 human habitations and5 cattlesheds of each of selected 4 major villages(Bajitpur, Baligori, Mirzapur and Bhanjipur) of Tarakeswar area of Hooghly district, West Bengal, India.
Collections were done both from human habitations andcattlesheds because there were a large number of cattlesheds very close to human habitations. One insect
collector collected mosquitoes for 12 min per habitation/shed i.e. for 120 min (2 hrs) from 10 habitations/sheds of each village in each month. Thus a total of 192
man‑hour (2 hrs×4 villages×24 months)was employed
for collection in two years from January ʼ
96 to December ʼ
97. M oreover, man‑bait collections were made(following the method of Chandra and Hati,1993)from
6 p.m. to 6 a.m. both at indoor and outdoor locations,once a month for one year from January ʼ
97 to December ʼ
97 (thrice in a year i.e.once in each season in eachvillage) employing a total of 288 man‑hour (12 hrs×2
locations×3 seasons×4 villages).
Salivary glands and guts of 621 An. subpictus, 621
An. vagus, 621 An. barbirostris and 65 An. annularis
mosquitoes (indoor‑resting and man‑landing) weredissected and examined to detect sporozoites and/or
oocysts of Plasmodium. Sporozoite species wereidentified by ELISA test. Sibling species of An.
subpictus was ascertained on the basis of banding pattern of polytene chromosome as described by Suguna(1982). A total of 120 mosquitoes were examined forpolytene chromosome observation (5 mosquitoes fromeach village in each season for two years i.e. 5 mos-Mosquito Research Unit, Department of Zoology, Burdwan University, West Bengal, India
Authors correspondence should be sent to G. Chandra

178

quitoes×4 villages×3 seasons×2 years＝120).
Blood meals of 480 indoor‑resting engorged An.
subpictus (collected in the morning hours from humanhabitations of all the villages in all the three seasons)
were tested by Ouchterlonyʼs gel diffusion technique(Ouchterlony and Nilson, 1973) against human, bovine,
avian and goat antisera to determine the anthropophilic
index.
Age composition of An. subpictus population wasdetermined on the basis of the number of ovariolar
dilatations (Polovodova, 1949 ). Ovarioles of 300 mosquitoes were examined which were collected in themorning hours from all the four villages in all the threeseasons. Daily survival rate and daily mortality rate
were calculated with the method of Davidson (1954)andService (1976) respectively. Survival rate per gonotrophic cycle was determined with the help of log curve
following the M ethod of Chandra et al. (1996). The
gonotrophic cycle of blood feeding insects is determinedby the time taken between successive blood meals andegg laying (WHO,1975). The duration of each gonotrophic cycle of a laboratory‑maintained An. subpictus
colony was estimated by artificial blood feeding in threesets of experiments conducted during each season,
namely summer, winter and rainy seasons at normal
temperature. Though there is no evidence that the
gonotrophic cycle of the wild population would be essentially the same as those of populations in cages (Chandra et al., 1996).
Eight small ponds, 8 submerged fields and 8 drains(2 from each village) were searched for An. subpictus

larvae in the studyarea. Larvae were collected with 250
ml dipper. One hundred dips were given in each pond/
field/drain in each season. Larvac were counted,
examined and larval species were determined. Moreover, temporary water collections (available only during monsoons) were searched for Anopheles larvae.

RESULTS
During the two year study period altogether 4,717(1,830 from human habitations and 2,887 from cattlesheds) indoor‑resting Anopheles mosquitoes were collected of which An. subpictus predominated over theothers,comprising 50% (2,356)of them with a densityof
12.3 per man‑hour. Other species were An. annularis(65; 1.4%), An. barbirostris (1,187; 25.2%) and An.
vagus (1,109; 23.5%). Monthly collection of An.
subpictus from Januaryʼ
96 to December ʼ
97 (two years)in 4 villages has been presented in Table 1. Seasonal
prevalence of An. subpictus during rainy (Jul.‑Oct.),
winter (Nov.‑Feb.) and summer (Mar.‑Jun.) was
49.3%, 13.8% and 36.9% respectively.
During one year man‑bait collection, the same 4
Anopheles species (Like indoor‑resting population)
were encountered and An. subpictus comprised of 48.3%(156) out of altogether 320 Anopheles mosquitoes
caught. Density per man‑hour and per man night of
man‑landing An. subpictus population was 0.54 and 13.0,
respectively. Among the biting population,43.6%,14.7%
and 41.7% came to bite in rainy, winter and summer
seasons, respectively. M onthwise collection of man‑

Table 1 M onthly collection of An. subpictus from human habitations(H) and cattlesheds(C) of 4 villages of Tarakeswar
area during Jan. 1996 to Dec. 1997
M onth
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Total

Bajitpur
H
C
2
10
12
42
28
51
23
36
18
25
35
70
52
93

Name of the villages
Baligori
M irzapur
H
C
H
C
1
7
1
9
7
26
11
22
20
45
18
40
15
24
21
16
12
16
5
20
28
51
30
55
39
74
41
64

Bhanjipur
H
C
1
7
6
36
16
32
12
20
12
14
20
41
32
80

Total
No.
%
38
1.62
162
6.88
250
10.61
167
7.09
122
5.18
330
14.00
475
20.16

38
31

61
47

38
25

46
35

35
25

39
33

22
29

29
30

308
255

13.07
10.82

7
4
0
250

36
29
13
513

5
1
1
192

37
20
12
393

1
2
1
191

12
13
4
327

4
2
2
158

22
19
2
332

124
90
35
2,356

5.26
3.82
1.49
100

179
Table 2 M onthwise collection of An. subpictus off human baits during night (6 p.m. to 6 a.m.) extending from January
1997 to December 1997 in Tarakeswar area
IndoorM onthNumber Percent(%)

Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.

Total

Per man‑hour
Per man‑hour
Per man‑hour
Number Percent(%)
Number Percent(%)
collection
collection
collection

3
7

3.19
7.45

0.25
0.58

1
6

1.61
9.68

0.08
0.50

4
13

2.56
8.33

0.16
0.54

13
9

13.83
9.58

1.08
0.75

8
5

12.90
8.06

0.66
0.41

21
14

13.46
8.98

0.87
0.58

8
9

8.51
9.58

0.66
0.75

6
7

9.68
11.30

0.50
0.58

14
16

8.98
10.26

0.58
0.66

14
12

14.89
12.76

1.16
1.00

10
9

16.13
14.52

0.83
0.75

24
21

15.38
13.46

1.00
0.87

9

9.58

0.75

5

8.06

0.41

14

8.98

0.58

6
2
2

6.39
2.12
2.12

0.50
0.16
0.16

3
1
1

4.84
1.61
1.61

0.25
0.08
0.08

9
3
3

5.77
1.92
1.92

0.37
0.12
0.12

94

100.000.65

62100.000.43

156

100.00

0.54

Oct.
Nov.
Dec.
Total/
Average

Outdoorlanding An. subpictus has been presented in Table 2.
Natural sporozoite infection was detected in thesalivary glands of one man‑landing An. subpictus (outof 156 dissected) and one indoor‑resting An. subpictus(out of 465 dissected)with the sporozoite rates of 0.64%
and 0.21%,respectively. Overall sporozoite rate of An.
subpictus (combining indoor‑resting and man‑landing
population) was 0.32%. The sporozoite species was
detected to be P. vivax in both the cases. All the otherspecies of Anopheles dissected, were negative for sporozoite infection. No gut infection with oocysts was
detected in any anopheline species available in the studyarea.
Out of 480 indoor‑resting An. subpictus subjected toprecipitin test, 197 (41.0%) were positive for humanblood. Rests (59.0%) were positive for bovine blood.
None of the engorged An. subpictus imbibed avian andgoat blood.

Duration of gonotrophic cycle of An. subpictus was
98 hrs, 102 hrs and 88 hrs in rainy, winter and summer
seasons respectively. Average duration of the cycle wascalculated to be 96 hrs (4 days). Number of mosquitoesof different parous state, proportion parous, daily survival rate and daily mortality rate of natural population
have been presented in Table 3. Survival rate per
gonotrophic cycle averaged over two years was 0.58
which was obtained from log curve and the slope of thestraight line was −0.234. Among the female An.
subpictus population 14.5% passed 3 or more gonotrophic cycles in natural condition.
Larval density of An. subpictus in different types ofbreeding places in different seasons have been presented
in Table 4. All the An. subpictus mosquitoes, collected
in all the seasons form all the villages of the study areaand examined for polytene chromosome, were detected
to be as sibling species A (fresh water from).

Table 3 Seasonal proportion parous (PP), daily survival rate (DSR) and daily mortality rate (DM R) of An. subpictus
population of the study area
SeasonNo. dissected

Summer(M ar.‑Jun.)

Mosquitoes of different parous

PP

DSR

DM R

1

0.33

0.76

24％

13

7

0.56

0.86

14％

20

13

8

0.65

0.90

10％

41

28

16

0.51

0.84

16％

NP

P

P

P

P

100

67

25

5

2

Rainy
(Jul.‑Oct.)

100

44

20

16

Winter
(Nov.‑Feb.)

100

35

24

Total

300

146

69

Correlation coefficient between the number of dilatations and the number of females in each dilatation class＝−0.9159.

180
Table 4 Larval density of An. subpictus in different types of breeding places in different seasons in the study area

Summer(M ar.‑Jun.)

800

Pond
(
No.and percent)collected
836

Rainy
(Jul.‑Oct.)800(17.25)
3,757

Winter
(Nov.‑Feb.)

800(77.54)
252

SeasonTotal

No. of dips

2,400

(5.20)
4,845
(100)

Drain
(
No.and percent)densitycollected
per dip
17
0.02

density
per dip
1.04
4.70(24.28)49

0.31(70.0)4

2.01

DISCUSSION
Information on the role of An. subpictus as thevector of malaria in India is limited. Sibling species B(brakish water form) of An. subpictus has been incriminated as vector in some coastal areas of South
India (Russel and Jacob, 1939; Russel and Rao, 1940;
Panicker et al., 1981) in the presence of some otherrecognised vectors. In the present study area of Tarakeswar, W.B., India, species A of An. subpictus ispredominating over the other anophelines and has been
incriminated for the first time as the vector of humanmalarial parasite in absence of any other recognised
vector. Species B has not been available probably
because the study area is nearly 175 km away from thesea (Bay of Bengal).
Anthropophilic index (41.0)of indoor‑resting population is moderate but higher than other places recorded
so far (Senior White, 1938; Roy, 1943; Bruce Chwatt,
1966; Kulkarni, 1983; Hati, 1986; Collins et al., 1989;
Banerjee et al., 1991; Abhaywardana et al., 1996) indicating considerable extent of man vector contact. No
preference to avian blood meal excludes the probabilityof transmitting avian malaria.
Proportion parous (0.51) and daily survival rate
(0.84) are very high and survival rate per gonotrophic
cycle (0.58) is consistent with high proportion parous.
14.5% of the female An. subpictus population havepassed 3 or more gonotrophic cycles in nature whichindicates that a considerable portion of the wild population can survive long enough in nature to develop sporozoites in them and thereby able to transmit malaria
successfully.
The prevalence of indoor‑resting population of An.
subpictus was higher in the rainy season. Man‑bait
experiments also indicate that theycame to bite more in
the rainy season. The cause of such higher prevalence(5.71)
70(100)

Submerged field
No.and(percent)densitycollected
per dip
230
0.29

0.06

(6.87)
2,982

3.73

0.005

(89.14)
133

0.17

0.03

(4.0)
3,345
(100)

1.40

of this species may be due to greater breeding facilities
during rainy season in the paddy fields, shallow ponds
and also in the temporary water collections. When
breeding places were searched, per dip density of An.
subpictus larvae was always higher in the rainyseason in
all types of breeding places. This is worthy mentioningthat they breed more, take rest in more number inhuman habitations and cattlesheds and also bite morecoinciding with the higher number of malaria cases
during rainy season in present study area.
Present findings help us to establish the role of An.
subpictus as a primary vector of malaria in absence of
any other recognised primary vector in an area (Tarakeswar, West Bengal) in Indian subcontinent. Naturalinfection of P. falciparum in the mosquitoes was notavailable, may be, due to lower incidence of P. falciparum malaria cases is the study area. Further studies arenecessary to find out its role as vector in other parts ofthe country.

REFERENCES
1) Abhayawardana,T.A.,Wijesuriya,S.R.E and Dilrukshi,
R.K.C.(1996):Anopheles subpictus complex:Distributionof sibling species in Sri Lanka. Indian J. Malariol., 33,
53‑602) Banerjee,P.K.,Ghosh,K.N.and Chatterjee,R.N.(1991):
Gel diffusion analysis of host preference pattern ofAnopheles subpictus in West Bengal, India. Indian J.
Malariol., 28, 157‑159
3) Bruce Chwatt, L.J., Garrent Jones, C., Weitz, B. (1966):
Ten yearsʼstudy of host selection by anopheline mosquitoes. Bull. Wld. Hlth. Org., 35, 405‑435
4) Chandra,G.and Hati,A.K. (1993):Correlation between
the preferred biting site ofCulex quinquefasciatus and theregion of the body affected by clinical filariasis. Annals
Trop. M ed. Parasit., 87, 393‑397
5) Chandra,G.,Seal,B.and Hati,A.K. (1996):Age compo-

181
sition of the filarial vector Culex quinquefasciatus(Diptera:Culicidae) in Calcutta, India. Bull. Ent. Res.,86, 223‑226
6) Collins, R.T., Sharma, G.K. and Dhal, K.B. (1989 ):Gel
diffusion determinations on feeding behaviour patternsof Anophelines in Orissa State.India.J.Com.Dis.,21,1‑
237) Davidson, G. (1954):Estimation of the survival rate ofAnopheline mosquitoes in nature. Nature, 174, 792‑793
8) Ferreira, A.P. and Breda, A.V.M.A. (1962):Anis. Inst.
Med. Trop. Lisb., 20, 73
9) Hati, A.K. (1986):Studies on Culex vishnui and related
vectors of Japanese encephalities in rural West Bengal.
Monograph,Cal.Sch.Trop.Med.,Govt.ofWest Bengal,
p.1‑140
10) Hearth, P.R.J., Abhayawardana, T.A.and Padmelal,U.
K.G.K. (1983): A study of the role of different anopheline species in the transmission of human malaria in
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Lanka. Assoc. Adv. Sci., 39, 6
11) Kulkarni, S.M. (1983):Detection of sporozoites in Anopheles subpictus in Bastar district, Madhya Pradesh.
Indian J. M alariol., 20, 159 ‑160
12) Ouchterlony, O. and Nilson, L.A. (1973): Immunodiffusion and immunoelectrophoresis. Handbook of Experimental Immunology, Oxford, Blackwell Pub., 1‑99
13) Panicker, K.N., Geetha Bai, M ., Bheema Rao, U.S.,
Viswam, K. and Suryanarayanmurthy U. (1981): Anopheles subpictus, vector of malaria in coastal villages ofSouth‑East India. Current Science, 50, 694‑695
14) Polovodova, V.P. (1949 ): The determination of the＊Cited in Panicker et al. (1981)

physiological age of female Anopheles by the number ofgonotrophic cycles completed. Medskaya. Parazit., 18,352‑355
15) Roy, D.N. (1943): The Role of Anopheles subpictus
Grassi as a carrier of malaria. J.M al.Inst.India,6,117‑
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543‑56218) Russel, P.F., West, L.S., Manwell, R.D. and M acdonald,
G. (1963):Practical M alariology 2nd ed.Oxford University Press, London, 44, 275
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Jeypore hills part II. A second yearsʼresults J.M al.Inst.
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20) Service, M.W. (1976): Mosquito Ecology: Field Sampling Method. London,Applied Science Publishers Ltd.
21) Suguna, S.G. (1982): Cytological and morphologicalevidence for sibling species in Anopheles subpictus Grassi. J. Com. Dis., 15, 1‑822) Van Hell,J.C. (1952):Documenta M ed.Geor.Trop.,4,4523) WHO (1964):Expert Committee on M alaria II report.
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183

Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 183‑187

THE EFFECT OF REPEATED FOUR MONTHLY
TREATMENTS ON THE PREVALENCE AND
WORM BURDEN OF ASCARIS, TRICHURIS ANDHOOKWORM INFECTIONS IN AN ENDEMIC AREANORHAYATI BINTI M OKTAR, PAKEER OOTHUMAN AND FATMAH M OHD SALLEH
Received February 14, 2000/Accepted July 27, 2000

Abstract: The effect ofrepeated 4 monthlytreatment ofsingle dose of400 mg albendazole on the prevalence
and worm burden of Ascaris, Trichuris and hookworm was studied in an endemic area. Repeated 4 monthly
treatment, had significant effect in reducing the worm burden of Ascaris and not the prevalence. As for
hookworm infection repeated 4 monthly treatment had significant impact in reducing both prevalence andworm burden in the community. However, repeated 4 monthly treatments had no significant impact inreducing the prevalence and worm burden of Trichuris infection in the community. Trichuris infection
should be considered as a continuing infection rather than reinfection because of poor cure rate of albendazole at the onset of the study. Significant and strong predisposition (p＜0.0001)were detected after single
and repeated 4 monthly treatment in Ascaris and Trichuris infection but not in hookworm infection.
Stratification of data indicated that significant and strong predisposition was also seen in gender. This study
concludes that changes in mean egg count per gram (mean EPG)is a sensitive indicator in measuring effectof treatment in an endemic area, and repeated 4 monthly treatments has successfully reduced the worm
burden of Ascaris and hookworm infection. Subjects remained predisposed to Ascaris infection over 2
reinfection periods,and for hookworm infection evidence of predisposition was seen only over 1 reinfection
period.
Key words: Predisposition, Ascaris, Trichuris, hookworm, reinfection

INTRODUCTION
In highly endemic areas of Ascaris, Trichuris andhookworm infections,reinfection can occur as earlyas 2months after treatment (Norhayati et al., 1995). By 4
months almost half and one‑tenth of the population
treated become reinfected with Ascaris and hookworm
respectively (Norhayati et al., 1997), and by 6 months
the intensity of infection of Ascaris and Trichuris weresimilar to pre‑treatment levels (Elkins et al., 1988;
Albinco et al., 1995). Thus a 4 monthly targeted chemotherapy in highly endemic areas may be necessary inorder to have an impact on the prevalence and intensityof infection of Ascaris and hookworm infections (Bundy
et al., 1990;Albinco et al., 1995;Norhayati et al., 1997).

Predisposition to reinfection following single‑treatment
has been reported in hookworm infection (Schad andAnderson, 1985), Ascaris infection (Elkins et al., 1986;
Thein‑Hlaing et al., 1987;Haswell‑Elkins et al., 1987;
Forrester et al., 1990)and Trichuris infection (Haswell‑
Elkins et al., 1987;Bundyet al., 1987;Bundyand Cooper,
1988; Forrester et al., 1990). Predisposition has also
been reported following repeated treatments (2 reinfection period) in Ascaris infection (Holland et al., 1989;
Hall et al., 1992; Chan et al., 1992) and in Trichuris
infection (Chan et al., 1992).
This intervention study was conducted in a highly
endemic area of Ascaris,Trichuris and hookworm infections. The objectives of this study were to evaluate theimpact of 4 monthly 400 mg albendazole treatment for

Department of Parasitology and M edical Entomology, Faculty of Medicine, Universiti Kebangsaan M alaysia, Jalan Raja M uda Abdul
Aziz, 50300, Kuala Lumpur, M alaysia
Address for correspondence: Associate Prof. Dr. Norhayati binti M oktar
Department of Parasitology and M edical Entomology, Faculty of M edicine Universiti Kebangsaan M alaysia, Jalan Raja Muda Abdul
Aziz, 50300, Kuala Lumpur,
Fax: (603)2982640 E‑mail:hayati＠medic.ukm.my184

12 months on the prevalence and intensity of infection/
worm burden (mean eggs per grasm‑EPG) of Ascaris,
Trichuris and hookworm infections and to examine theevidence of predisposition over 2 reinfection periods.

M ATERIALS AND M ETHODS
Study Area
This study was part of a bigger study conductedamong residents of 6 Orang Asli (Aborigine)villages inthe sub‑district of Dengkil, Selangor, M alaysia. It was
situated about 50 km from Kuala Lumpur,the capital of
Malaysia. Each village comprised a very small population and most of the residents worked as palm oil estatelabourers, rubber tappers, farmers or were engaged
doing odd jobs such as fishing and selling forest products. Most of them lived in single‑roomed houses madeof bamboo and wood. Almost all the houses in thevillages had no electricity, no pipe water nor toilet
facilities. The residents used well or river water fordaily use and defaecated in the open among the bushes.
Subjects and Parasitologic Surveys
In all 205 children (95 males and 110 females)aged
1‑13 years old were included in this study. Stool samples were collected and those found infected were treated with 400 mg of albendazole periodically at 4 months
interval for 1 year. The prevalence and worm burden of
Ascaris,Trichuris and hookworm infection at pre‑treatment (phase ), at 4 months after single treatment(phase ) and at 12 months after repeated treatments(four monthly intervals‑phase ) were determined
before each intervention and compared. To measure theefficacy of albendazole, stool samples were collected
and examined at 1 month after single treatment. All
samples were examined bythe Kato‑Katz technique andworm burden was measured indirectly as EPG (WHO,1987). For Ascaris, EPG of 1‑9,999, 10,000‑49,999 and
50,000 and above is defined as mild,moderate or severe
infection respectively. For Trichuris and hookworm
EPG of 1‑1,999, 2,000‑9,999 and 10,000 and above isdefined as mild,moderate or severe infection respectively (WHO, 1987).
The efficacy of albendazole in reducing the prevalence and worm burden was measured by cure rate andmean egg count reduction rate respectively. Cure rate is
the percentage of cured cases at 1 month after the single
treatment. The mean egg count reduction rate is the
reduction between the mean EPG at 1 month after
treatment and the mean EPG at pre‑treatment,expressed as a percentage of the mean EPG at pre‑treatment.

Statistical Analysis
Changes in the prevalence and worm burden wascompared by 2 proportional test and by paired t‑test
after logarithmic transformation of data respectively.
Correlation of egg counts were analysed using KendallʼsRank Correlation Test. Data were analysed using
EpiInfo (EpiInfo version 6.02, 1994) and SPSS for
Windows (SPSS, 1993).

RESULTSThe overall pre‑treatment prevalence of Trichuris,
Ascaris, and hookworm infections in 205 children (95boys and 110 girls)was 91.7%,62.5% and 28.8% respectively. Almost two‑third were infected with moderateand severe infections of Trichuris, 46.3% had moderateand severe infections of Ascaris and only 1.5% had
moderate infection of hookworm. The cure rate ofAscaris infection was 97.4% and the mean egg countreduction rate was 99.9%; the cure rate of hookworm
infection was 93.1% and the mean egg count reduction
rate was 96.6%. The cure rate of Trichuris infection
was low (5.5%),however the mean egg count reduction
rate was more evident (49.1%).
Prevalence of Ascaris, Trichuris and hookworm infections
Table 1 shows the prevalence of Ascaris, Trichuris
and hookworm infections at phase , phase
andphase . The overall prevalence of Ascaris infection atphase and decreased by31.8% and 7.2% respectively, compared with phase . However the difference
was not statistically significant. The increase in theprevalence of Trichuris infection at phaseandcompared with phase by 2.3% and 5.0% respectively
was not statistically significant. For hookworm infection,the overall prevalence at phase and comparedto phasedecreased by 63.9% and 69.8% respectively
and the difference was statistically significant.
Although the prevalence of Ascaris and Trichuris infections increased in phasecompared to phase , thedifference was not statistically significant.
Thedecrease in the prevalence of hookworm infection
between phaseandwas also not significant.
Intensity of Ascaris, Trichuris and hookworm infections
Table 2 shows the mean geometric EPG of Ascaris,
Trichuris and hookworm infections at phase , phaseand phase . The mean EPG of Ascaris at phaseanddecreased by 53.3% and 75.0% respectively
compared with phase and the difference was statisti-

185
Table 1 Prevalence of Ascaris, Trichuris and hookworm infection at phaseⅠ, Ⅱ and Ⅲ
Prevalence (%)

Infections
Phase
AscarisTrichuris
Hookworm

Percent reduction
‑ /
‑ /

62.5
91.7

42.6
93.8

58.0
96.3

−31.8(ｐ＞0.05)＋ 2.3(ｐ＞0.05)− 7.2(ｐ＞0.05)＋ 5.0(ｐ＞0.05)

28.8

10.4

8.7

−63.9(ｐ＜0.05)−69.8(ｐ＜0.05)

Table 2 M ean intensity of Ascaris, Trichuris and hookworm infection at phase
Mean EPG (Geometric)

Infections
Phase
AscarisTrichuris,and24,071

11,251

6,008

Percent reduction‑ /‑ /−53.3(ｐ＜0.05)−75.0(ｐ＜0.05)

5,516
131

5,604
59

5,822
10

＋ 1.6(ｐ＞0.05)−55.0(ｐ＜0.05)

Hookwormcallysignificant. For Trichuris,the increase in the mean
EPG at phase and compared with phase by1.6%
and 5.5% respectively was not statistically significant.
For hookworm infection, there was a significant
decrease of mean EPG at phaseandcompared tophase . Although the mean EPG of Trichuris infection
increased in phasecompared to phase , the difference was not statistically significant. The decrease in
the mean EPG of Ascaris and hookworm infections
between phaseandwas statistically significant.
Correlation of egg counts
The correlation for overall and stratified EPG of
Ascaris, Trichuris and hookworm infections according
to gender at phase ,andare shown in Table 3.
Analysis shows that in Ascaris infection, there is astrong and significant positive correlation of mean EPG
between phase and and phase and . When thedata was stratified according to gender, the level ofsignificance remained strong and significant except inmales between phase and .
In Trichuris infection,strong and significant overallcorrelation was detected in all phases and when the data
was stratified according to gender. In hookworm infection significant correlation was detected between phaseandand between phaseandbut with lower
significant level. When the data was stratified according to gender, significant correlation was detected inmales (phase &and phase & )and in females(phase & ), although the level was lower.

DISCUSSION
In endemic areas of Ascaris, Trichuris and hookworm infections,where reinfections occur continuously,＋ 5.5(ｐ＞0.05)−92.4(ｐ＜0.05)

repeated treatments with effective antihelminthic wererequired to reduce worm burden (measured by mean
EPG) in the community. The interval required varied.
A studydone in Burma suggests that 3 monthlyrepeatedtreatments give significant impact on the prevalence
and worm burden of Ascaris (Thein‑Hlaing et al.,1987).
In contrast, a study in M alaysia reports that 6 monthly
repeated treatment has significant effect in reducing
both prevalence and worm burden of Ascaris and Trichuris (Chan et al., 1992). On the other hand, otherstudies show that by 6 months to 1 year,the prevalence
and worm burden of Ascaris and Trichuris have reached
Table 3 Correlation of Ascaris, Trichuris and hookworm
mean EPG between phase andand phaseandGroup
AscarisOverall
GenderMale
FemaleTrichuris
Overall
GenderMale
FemaleHookworm
Overall
GenderMale
Female

Phase

and

Phase

and

0.35170.29020.35310.24570.3522

0.34800.53880.4474

0.55330.41980.53270.47580.33040.13770.2730＊0.11730.4007−0.0564＊Significant correlation at p＜0.05
Significant correlation at p＜0.01
Significant correlation at p＜0.0001

186

the pre‑treatment level (Holland et al., 1989;Elkins etal., 1988;Albonico et al., 1995).
We studied the impact of 4 monthly treatment (for12 months) on the prevalence and worm burden of
Ascaris, Trichuris and hookworm infections in an
endemic area. The results of our study showed that
repeated 4 monthlytreatments had no significant impact
in reducing prevalence and worm burden of Trichuris
infection in the community and this was different froman earlier study done in M alaysia (Chan et al., 1992).
Poor cure rate of single dose of 400 mg albendazole
against Trichuris infection and high prevalence ofmoderate and severe infections of the worm in thiscommunity compared to the study done by Chan et al.
(1992)were the main reasons for the failure of repeated
4 monthly treatments in reducing prevalence and worm
burden of Trichuris infection. In the present study,
Trichuris infection should be considered as a continuing
infection rather than reinfection because of poor curerate at the onset. This factor explains the increases inprevalence and worm burden of Trichuris infection inthis study.
Repeated 4 monthly treatments had significant
effect in reducing worm burden of Ascaris but not theprevalence. The increase in Ascaris prevalence after
repeated 4 monthly treatments can be explained by thecontinuing infection in the community. This factor
suggests that the use of antihelminth can only control
this infection by significantly reducing the worm burdenin the communityand not prevent people from becoming
infected. As for hookworm infection,repeated 4 monthly treatments had significant impact in reducing bothprevalence and worm burden in the community. Low
prevalence,low worm burden and a drastic reduction inworm burden in the community following treatment
may explain these findings. Besides that,the speed withwhich the worm burden bounces back to its pre‑treatment level differs between species for example it isslower in hookworm and faster in Trichuris and Ascaris(Anderson, 1986). This finding also indicates that themean egg count is a sensitive indicator in evaluating the
progress of periodic chemotherapy in the control ofAscaris and hookworm infections. A similar finding wasreported by Anderson and May (1985).
Based on this study, it is more relevant to suggest
implementation of repeated 4 monthly treatments in theplanning of periodic chemotherapy schedule in an
endemic area. Such a suggestion is also supported byour earlier study in the same community,where after 4
months of treatment,the reinfection rate of Ascaris andhookworm was seen in 50.0% and 10.0% of the subjects
respectively (Norhayati et al., 1997). Only one‑fifth of
the subjects infected with Ascaris reached their pre‑treatment intensity (Norhayati et al., 1997). Ourpresest study also suggests that the mean EPG should be
used as an indicator to monitor the progress of periodic
chemotherapy in the community.
This study examines the evidence of predisposition
over one and two reinfection periods of Ascaris, Trichuris and hookworm infections. For Trichuris infection evidence of predisposition was seen over one andtwo reinfections. This evidence was seen as a result ofpoor cure rate at the start.
As for Ascaris infection, evidence of predisposition
was seen after one and two reinfection periods. Thisfinding generally agreed with most of the studies done
before (Holland et al., 1989;Hall et al., 1992;Chan etal., 1992). For hookworm infection evidence of predisposition after one reinfection period was weak and after
two reinfection periods, the evidence was negative.
Predisposition following one reinfection period has beenreported in hookworm infection by Schad and Anderson(1985). These findings indicate that subjects remained
predisposed to Ascaris infection over 2 reinfection
periods and for hookworm infection evidence of predisposition was only seen over 1 reinfection period.
It can be concluded that repeated 4 monthly treatments have successfully reduced the worm burden of
Ascaris and hookworm infection in the Orang Aslicommunity. The risk of acquiring similar worm burden
as before treatment was only evident in Ascaris and notin hookworm infection.

REFERENCES
１) Albonico, M., Smith, P.G., Ercole, E., Hall, A.,Chwaya,
H.M ., Alawi, K.S. and Savioli, L. (1995): Rate of reinfection with intestinal nematodes after treatment ofchildren with mebendazole or albendazole in a highly
endemic areas. Trans.R.Soc.Trop.Med.Hyg.,89,538‑
541２) Anderson,R.M .and M ay,R.M . (1985): Helminth infections of humans: mathematical models, population
dynamics and control. Advances in Parasitology,24,1‑
101３) Anderson, R.M . (1986): The population dynamics andepidemiology of intestinal nematode infections. Trans.
R. Soc. Trop. Med. Hyg., 80, 686‑696
４) Bundy, D.A.P., Cooper, E.S., Thompson, D.E., Didier, J.
M.,Anderson,R.M.and Simmons,I. (1987): Predisposition to Trichuris trichiura infection in humans. Epid.
Infec., 98, 65‑71

187５) Bundy,D.A.P.and Cooper,E.S. (1988): The evidence ofpredisposition to trichuriasis in Caribbean communities.
Trans. R. Soc. Trop. Med. Hyg., 82, 251‑256
６) Bundy, D.A.P., Wong, W.S., Lewis, L.L. and Horton, L.
(1990): Control of geohelminths by delivery of targetedchemotherapy through schools. Trans. R. Soc. Trop.
Med. Hyg., 84, 115‑120
７) Chan,L.,Kan,S.P.and Bundy,D.A.P.(1992): The effectof repeated chemotherapy on the prevalence and intensity infection of Ascaris lumbricoides and Trichuris
trichiura. Parasitol., 104, 371‑377
８) Elkins, D.B., Haswell‑Elkins, M .R. and Anderson, R.M.
(1986): The epidemiology and control of intestinal
helminths in the Pulikat Lake region of Southern India
1. Study design and pre‑ and post‑treatment observation on Ascaris lumbricoides infection. Trans. R. Soc.
Trop. M ed. Hyg., 80, 774‑792
９) Elkins, D.B., Haswell‑Elkins, M .R. and Anderson, R.M.
(1988): The importance of host age and sex to patternsof reinfection with Ascaris lumbricoides following mass
anthelminthic treatment in a South Indian fishing community. Parasitol., 96, 171‑184
10) EpiInfo version 6.02. A word processing Data base &Statistics Program for Public Health. Produced by The
Division of Surveillance and Epidemiology,
Epidemiology Program off Centres for Diseases Control& Preventive and World Health Organization. 1994.
11) Forrester, J.E., Scott, M .E., Bundy, D.A.P. and Golden,
M.H.N. (1990): Predisposition of individual and families in Mexico to heavy infection with Ascaris lumbricoides and Trichuris trichiura. Trans. R. Soc. Trop.
Med. Hyg., 84, 272‑276
12) Hall,A.,Anwer,K.S.and Tomkins,A.M. (1992): Intensity of reinfection with Ascaris lumbricoides and its

implication for parasite control. Lancet,339,1253‑1257
13) Haswell‑Elkins, M.R., Elkins, D. and Anderson, R.M .
(1987): Evidence of predisposition in humans to infection with Ascaris, hookworm, Enterobius and Trichuris
in a South Indian fishing community. Parasitol., 95,
339 ‑354
14) Holland, C.V., Asaolu, S.O., Crompton, D.W.T., Stoddart, R.C., M acDonald, R. and Torimiro, S.E.A. (1989 ):The epidemiology of Ascaris lumbricoides and othersoil‑transmitted helminths in primary school children
from Ife‑Ife, Nigeria. Parasitol., 99, 275‑285
15) Norhayati,M .,Oothuman,P.,Fatmah,M .S.,Muzain,M .
Y. and Zainuddin, B. (1995): Hookworm infection andreinfection following treatment among Orang Asli children. M ed. J. Malaysia, 50, 314‑319
16) Norhayati, M.,Oothuman,P.,Azizi,O.and Fatmah,M .
S. (1997): Efficacy and effect of single dose albendazoleon the prevalence and intensity infection of soil‑transmitted helminths in Orang Asli (Aborigines)children in
Malaysia. Southeast Asian J.Trop.Med.Pub.Hlth.,28,
161‑168
17) Schad, G.A. and Anderson,R.M . (1985): Predispositionof hookworm infection in humans. Science, 228, 1537‑
1540
18) Statistical Package for Social Sciences, for Windows(Release 6.0). 1993. SPSS Inc. Chicago, Illinois.
19) Thein‑Hlaing, Than‑Saw and M yint‑Lwin (1987):
Reinfection of people with Ascaris lumbricoides following single,6 months and 12 months interval mass chemotherapy in Opko village, rural Burma. Trans. R. Soc.
Trop. M ed. Hyg., 81, 140‑146
20) WHO (1987): Prevention and control of intestinal
parasitic infections. Tech. Rep. Ser. World HealthOrgan., 749

189

Jpn. J. Trop. Med. Hyg., Vol. 28, No. 3, 2000, pp. 189 ‑192

Research Note:

IDENTIFICATION OF TOXOPLASMA GONDIITACHYZOITES AND BRADYZOITES BY A
QUANTITATIVE COMPETITIVE POLYMERASE CHAIN
REACTION METHOD AFTER THE ACID TREATMENTHIDEKAZU HATA , FUM IE AOSAI , HYE‑SEONG M UN , M EI CHEN , M ASASHI KOBAYASHI ,ANUAR ABDULLAH KHAIRUL , HITOSHI KUBOSAWA AND AKIHIKO YANO
Received November 24, 1999 /Accepted June 21, 2000

Abstract: It was indicated that tachyzoites and bradyzoites of Toxoplasma gondii (T. gondii)defined bythe
susceptibility/resistance to acid treatment could be quantitatively analyzed by a quantitative competitive
polymerase chain reaction method targeting SAG1 gene, specific for T. gondii. The tachyzoites weredestroyed not only by pepsin‑HCl but also by HCl or other acid solutions. The acid‑induced destructions
occurred under the pH conditions lower than pH 1.8. Tachyzoite DNA of T. gondii was easily destructedby acid treatment. These DNA destructions made it possible to differentiate between tachyzoites andbradyzoites by QC‑PCR.
Key words: bradyzoite, HCl treatment, tachyzoite

INTRODUCTION
A physiological infection route of Toxoplasma gondii (T. gondii) to hosts including humans is the peroral
infection of cysts or oocysts. Jacobs et al. (1960a)
reported that tachyzoites were killed within a few
minutes of incubation in peptic digestive fluid, whereas
bradyzoites survived for up to 3 hrs. The difference ofresistance to digestive enzymes is used as a criterion todifferentiate between parasite stages (Frenkel, 1996;
Gross et al., 1996). Pepsin digestion technique has beenused to define bradyzoites in animal tissues (Dubey etal., 1997;Jacobs et al., 1960b;Remington et al., 1965).
However,bradyzoites are not easy to detect microscopically in digested materials,they were commonly detected by inoculation of the digested materials into mice orcats. A quantitative competitive polymerase chain
reaction (QC‑PCR) method was developed to assay the
number of T. gondii, an intracellular infective protozoan, by estimating the copy numbers of SAG1, a T.
１
２
３

gondii specific gene (Luo et al., 1995). In the present
study, we found that T. gondii tachyzoites and bradyzoites could be defined and quantitatively measured by
QC‑PCR after the acid treatment of T. gondii.

M ATERIALS AND M ETHODS
Cysts of an avirulent strain of T. gondii (Kamei etal., 1976) were prepared from B10.A(4R) mice. The
cysts were then purified from infected brain tissue on
45% Percoll gradients according to the method of Cornellissen et al. (1981). RH strain tachyzoites wereprepared according to the method described by Yano etal. (1989 ). The mouse cell lines L was maintained in
RPM I 1640 supplemented with 1% fetal bovine serum(FBS) and 0.1% Nutridoma (Boehringer Mannheim,
Mannheim, Germany).
The pepsin‑HCl solution was prepared as follows;
pepsin (Difco;1:10,000) 0.2 g;NaCl, 0.9 g;HCl, 1.4 ml;
and H O to make 100 ml of solution. The pepsin‑HCl

Department of Parasitology andSecond Department of Pathology, Chiba University School of M edicine, Inohana, Chiba 260‑8670, Chiba, Japan
Department of Parasitology, Faculty of Medicine, University of M alaya, 50603 Kuala Lumpur, M alaysia

Address for correspondence:Akihiko Yano, Department of Parasitology, Chiba University School of M edicine, Inohana,
Chiba 260‑8670, Chiba, Japan
Fax:043‑226‑2076 E‑mail:yano＠med.m.chiba‑u.ac.jp

190

solution was mixed with an equal volume of parasite
suspension containing tachyzoites or bradyzoites andincubated for 5, 15 or 30 min at 37°
C. After treatment
with digestive solution, parasites (3‑5×10 tachyzoites;
2‑3×10 bradyzoites per each well)were inoculated into
Falcon 24‑well plates (No.3047)previously seeded withL cells in RPMI 1640. One day after cultivation, toremove the free parasites, the medium was changed.
Two days after cultivation, the medium was removed
and the cells were washed twice with PBS. Then DNA
was extracted as previously described (Luo et al., 1995,
1997),and DNA was stored at −20°
C until use for PCR.
T. gondii was determined and calculated the numbers byquantitative competitive‑polymerase chain reaction (QC‑PCR) targeting the T. gondii SAG1 gene(surface specific antigen gene l)as previously described(Luo et al., 1995, 1997).

RESULTST. gondii tachyzoites and bradyzoites were treatedwith 0.1% pepsin‑HCl solution for various times at 37°
C.
The parasites were examined their infectivities to in
vitro cultured L cells after the treatment with pepsin‑
HCl. As shown in Table 1, none of the tachyzoites
treated for more than 15 min were infected to the cells,
as determined by QC‑PCR. In contrast,the bradyzoites
were not killed by pepsin‑HCl. They survived even 180
min after the treatment (not shown in Table 1), andretained the infectivity against the cultured cells. In
order to analyze precisely the susceptibility of tachyzoites to pepsin‑HCl, when tachyzoites were treatedwith pepsin‑HCl or HCl solutions, they lost the infectivity against L cells (Table 1). The tachyzoites
treated with acetic acid or sulfuric acid for more than 15
min also lost the infectivities against L cells. It wassuggested that the acids showed a destructive effectagainst T. gondii tachyzoites. The tachyzoites treatedwith pH 1.2 for more than 5 min, with pH 1.4 for morethan 15 min and with pH 1.8 for more than 30 min lostthe infectivity against L cells (Table 1). The infectivityof tachyzoites against cultured cells were affected withpH dependently. On the other hand,as shown in Table
2,when tachyzoites were treated with HCl solutions forone hour,DNAs of intracellular infecting tachyzoites aswell as free tachyzoites were not detected by QC‑PCR.
It was found out that their DNAs were degraded when
they were analyzed by QC‑PCR. Thus, DNA destructions of T. gondii tachyzoites made it possible to differentiate between tachyzoites and bradyzoites by QC‑
PCR.

Table 1 Destructive effects of acid treatment on T. gondii
tachyzoites determined by infectivities against L‑
cells
Treatment
Tachyzoite
Pepsin‑HCl

Time for treatment (min)＊
5
15
30
430

0

0

pH 2.5
1 N CH COOH

0
292
320
295
291
320

0
0
470
298
288
0

0
0
0
296
284
0

0.01 N H SO
Non‑treated

9
510

0
530

0
650

Bradyzoite
Pepsin‑HCl
Non‑treated

113

95

108

120

108

102

HCl
pH 1.2
pH 1.4pH 1.8pH 2.2＊T. gondii number per μg DNA measured by QC‑PCR.
0.1% pepsin‑0.084 N HCl.
Adjusted by HCl solution.

Table 2 Destructive effects of HCl treatment on T. gondii
free tachyzoites and intracellular tachyzoites
Number of T. gondii (QC‑PCR＊)
Free tachyzoites Itracellulartachyzoites
0
0
HCl
0
0
0.1% Pepsin‑HCl
310
380
Non‑treatedTreated with＊Tachyzoites were treated with pepsin‑HCl or HCl (0.084 N)
solutions for 1 hr at 37°
C,then T. gondii numbers per μg DNA
were measured by QC‑PCR.

DISCUSSION
The inter‑conversion of T. gondii between tachyzoites and bradyzoites is defined by their replication
velocity,by morphological criteria,by the expression ofbradyzoite‑specific molecules and genes, and by oral
infectivity against mice or cats (Gross et al., 1996).
Though identifications of tachyzoites or bradyzoites areimportant for diagnosis of toxoplasmosis, quantitative
measuring systems for definition of stage of T. gondii
have not been established. However, we described a
useful method for identification of tachyzoites andbradyzoites,and for measuring the T. gondii number intissues using QC‑PCR.
In the present study, number of T. gondii tachyzoites and bradyzoites can be quantitatively measured
by QC‑PCR targeting SAG1 gene of T. gondii after acidtreatment. T. gondii tachyzoites and bradyzoites
contained SAG1 gene in their genome,though SAG1 was

191

generally expressed in tachyzoites. QC‑PCR was developed to assay the number of T. gondii by estimating
copynumbers of SAG1 (He et al.,1997;Luo et al.,1995).
The truncated SAG1 was used as a competitor of the
QC‑PCR targeting SAG1 of T. gondii. The determinedamount of competitor SAG1 DNA was coamprified with
T. gondii genomic DNA. The band intensities of QC‑
PCR products were measured by comparison between
competitor band and genomic SAG1 gene products of
cDNA. From 1 to 10 copies of SAG1 can be quantitatedin 2 μg genomic DNA. This method is more sensitive
than any other cell counting methods for T. gondii.
M ost of the tachyzoites degenerated within 15 minof acid pepsin digestion. Jacobs et al. (1960a) also
reported that tachyzoites were damaged immediatelyby
acid pepsin treatment. Pettersen (1979 ) reported thatthe destruction of tachyzoites in HCl‑pepsin solution
was due to HCl, not pepsin. We further analyzed acidtypes and pH conditions which destroy tachyzoites invitro. We found that the tachyzoites were destroyed not
onlybyHCl but also byother acid solutions. Tachyzoite
destructions were occurred at pH conditions lower thanpH 1.8 in HCl treatment. These lower pH conditions arefound in the physiological life cycle of T. gondii, especially in the peptic digestive fluid of the stomach inhumans (pH 1.2‑2.3)(Geigy and Basle, 1956) and mice
(pH 1.4‑3.0) (Ogawa and Necheles, 1958). Pettersen(1979 ) suggested that tachyzoites had a higher permeability than bradyzoites, because tachyzoites were
stained faster than bradyzoites in a methylene blue dyesolution. The difference in acid‑mediated destruction
between tachyzoites and bradyzoites might be related toa difference in their surface membranes.
In the present study, the RH‑strain of tachyzoites
was easily degenerated by acid treatment. However,Dubey (1998) re‑evaluated the effects of acid pepsin on
T. gondii tachyzoites and bradyzoites. It was found that
the RH strain of T. gondii tachyzoites occasionallysurvived for 2 hrs in acid pepsin solution. However,thetransitional form between tachyzoites and bradyzoites
might explain the inconsistencies regarding the resistance to acid treatment. The development of a criterion
to supplement the well‑known characteristic of bradyzoites and tachyzoites is necessary to differentiate thestages of T. gondii.

REFERENCES
１) Cornelissen, A.W.C.A., Overdulve, J.P. and Hoenderboom,J.M .(1981): Separation of Isospora (Toxoplasma)gondii cysts and cystozoites from mouse brain tissue bycontinuous density‑gradient centrifugation. Parasitol.,
83, 103‑108２) Dubey, J.P., Speer, C.A., Shen, S.K., Kwok, O.C.H. andBlixt, J.A. (1997): Oocyst‑induced murine toxoplasmosis:life cycle, pathogenicity, and stage conversion inmice fed Toxoplasma gondii oocysts. J. Parasitol., 83,
870‑882３) Dubey, J.P. (1998): Re‑examination of resistance ofToxoplasma gondii tachyzoites and bradyzoites to pepsin
and trypsin digestion. Parasitol., 116, 43‑50
４) Frenkel, J.K. (1996): The stage‑conversion time of
Toxoplasma gondii:interpretation of chemical‑biologic
data out of parasitologic or host context. Parasitol.
Res., 82, 656‑658
５) Geigy,J.R.and Basle,S.A. (1956): Scientific Table,5thEd., p.284
６) Gross, U., Bohnem, W., Soete, M. and Dubremetz, J.F.
(1996): Developmental differentiation between tachyzoites and bradyzoites of Toxoplasma gondii. Parasitol.
Today, 12, 30‑33
７) He, N., Aosai, F., Luo, W.T., Ueda, M., Yang, T.H.,
Yamashita,K.,Sekiya,S.and Yano,A.(1997): Parasiteload in pregnant mice infected by Toxoplasma gondii
assayed by quantitative competitive‑PCR. Parasitol.
Int., 46, 143‑147
８) Jacobs, L., Remington, J.S. and M elton, M.L. (1960a):
The resistance of the encysted form of Toxoplasma
gondii. J. Parasitol., 46, 11‑21
９) Jacobs,L.,Remington,J.S.and M elton,M.L.(1960b): A
survey of meat samples from swine,cattle,and sheep forthe presence of Toxoplasma. J. Parasitol., 46, 23‑28
10) Kamei,K.,Sato,K.,Tsunematsu,Y. (1976): A strain ofmouse highly susceptible to Toxoplasma. J. Parasitol.,
62, 71411) Luo,W.T.,Seki,T.,Yamashita,K.,Aosai,F.,Ueda,M .
and Yano,A.(1995): Quantitative detection ofToxoplasma gondii by competitive polymerase chain reaction of
the surface specific antigen gene‑1. Jpn. Parasitol., 44,
183‑190
12) Luo, W., Aosai, F., Ueda, M., Yamashita, K., Shimizu,
K.,Sekiya,S.and Yano,A. (1997): Kinetics in parasite
abundance in susceptible and resistant mice infectedwith an avirulent strain of Toxoplasma gondii by using
quantitative competitive PCR. J. Parasitol., 83, 1070‑
107413) Ogawa,T.and Necheles,H.(1958): Gastric secretion in
the mouse. Am. J. Physiol., 194, 303‑307
14) Pettersen, E.K. (1979 ): Destruction of Toxoplasma gondii by HCl solution. Acta Path.Microbiol.Scand.Sect.
B., 87, 217‑220
15) Remington, J.S. and Cavanaugh, E.N. (1965): Isolationof encysted form of Toxoplasma gondii from humanskeletal muscle and brain. New Engl.J.Med.,273,1303‑
131016) Work, K. (1967): Isolation of Toxoplasma gondii fromthe flesh of sheep, swine and cattle. Acta Pathol.
Microbiol. Scand., 71, 296‑306

19217) Yano,A.,Aosai,F.,Ohta,M.,Hasekura,H.,Sugane,K.
and Hayashi, S. (1989 ): Antigen presentation by Toxo-

plasma gondii‑infected cells to CD4＋ proliferative T
cells and CD8＋ cytotoxic cells. J.Parasitol.75,411‑416

第28巻 第３号 平成12年９月
内容説
住民主体の健康づくり： 熱帯医学の知のモラル（英文）石川 信克 …………………………………………………………………………………………… ‑原著
インドネシアのスマトラにおけるブユ（双翅目： ブユ科）相調査成績（予報）（英文）高岡 宏行，M ohamad Yunus，Upik K. Hadi，Singgih H. Sigit，宮城 一郎 ………… ‑タイで採集されたブユ（双翅目：ブユ科）１新種の記載および新しく記録された９種について（英文）Chaliow Kuvangkadilok，高岡 宏行 …………………………………………………………… ‑Role of Anopheles subpictus as a Primary Vector of Malaria in an Area in India
Soumendranath Chatterjee and Goutam Chandra …………………………………………… ‑The Effect of Repeated Four M onthly Treatments on the Prevalence and Worm
Burden of Ascaris, Trichuris and Hookworm Infections in an Endemic Area
Norhayati Binti Moktar, Pakeer Oothuman and Fatmah Mohd Salleh ………………… ‑報
酸処理と QC‑PCR 法を用いた Toxoplasma gondii の tachyzoite と bradyzoite の同定（英文）畑英一，青才 文江，Mun Hye‑Seong，Chen M ei，小林仁，仁，矢野 明彦 …………………………………………… ‑Anuar Abdullah Khairul，窪沢

会報・記録
2000（平成12年）年度日本熱帯医学会役員名簿（2000年６月９日現在） …………………………
日本熱帯医学会雑誌編集委員名簿 ……………………………………………………………………… ‑投稿規定 …………………………………………………………………………………………………… ‑著作権複写に関する注意 …………………………………………………………………………………

S EP T EMB ER 2 0 0 0

CONTENTSJapanese Journal of Tropical M edicine and Hygiene Vol. 28 No. 3

総短V OL. 2 8 NO. 3

Review
Ishikawa, N.
Ethics of Tropical Medicine: People‑Centered Health Promotion Reflections from20 Years Experiences of Medical Cooperation in Bangladesh …………………………………

‑Original article
Takaoka, H., Yunus, M., Hadi, U.K., Sigit, S.H. and Miyagi, I.
Preliminary Report of Faunistic Surveys on Black Flies (Diptera: Simuliidae)
in Sumatra, Indonesia …………………………………………………………………………………

‑Kuvangkadilok, C. and Takaoka, H.
Taxonomic Notes on Simuliidae (Diptera) from Thailand:Description of a
New Species and New Distributional Records of Nine Known Species ………………………

‑Chatterjee, S. and Chandra, G.
Role of Anopheles subpictus as a Primary Vector of Malaria in an Area in India …………

‑

Moktar, N.B., Oothuman, P. and Salleh, F.M.
The Effect of Repeated Four Monthly Treatments on the Prevalence and Worm
Burden of Ascaris, Trichuris and Hookworm Infections in an Endemic Area ………………

‑

Research Note
Hata, H., Aosai, F., Mun, H‑S., Chen, M., Kobayashi, M., Khairul, A.A.,
Kubosawa, H. and Yano, A.
Identification of Toxoplasma gondii Tachyzoites and Bradyzoites by a Quantitative
Competitive Polymerase Chain Reaction Method after the Acid Treatment ………………

‑September 2000