bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of tick‐borne encephalitis virus transmission by tick salivary gland extracts
Authors: LABUDA M. , JONES L. D. , WILLIAMS T. , NUTTALL P. A.
Published: March 2008

Abstract. To investigate the role of ticks in TBE virus transmission, salivary gland extract (SGE) was derived from partially fed female Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus appendiculatus ticks. Guinea‐pigs were infested with uninfected R.appendiculatus nymphs and inoculated with a mixture of TBE virus and SGE or with virus alone. The number of ticks which on average acquired virus from feeding on animals inoculated with TBE virus and SGE from partially fed ticks was 4‐fold greater than the number that became infected by feeding on animals inoculated with virus alone or virus plus SGE from unfed I.ricinus. Viraemia was detected in 67% of guinea‐pigs inoculated with virus plus SGE compared to 30% of guinea‐pigs inoculated with virus alone. Virus titres in the blood were similar for both groups of animals [range 2.0‐2.8 log10 plaque‐forming units (PFU)/ml of blood]; however, the number of ticks that became infected was significantly higher on animals inoculated with virus plus SGE from partially fed ticks. No significant difference was observed with respect to the tick species used to derive SGE. The results indicate that TBE virus transmission is enhanced by factor(s) associated with the salivary glands of feeding ticks, and that these factor(s) may facilitate efficient transmission of TBE virus between infected and uninfected ticks even when they feed on hosts that have no detectable viraemia.
Bloodmeal digestion in the midgut of Phlebotomus papatasi and Phlebotomus langeroni
Authors: DILLON R. J. , LANE P.
Published: March 2008

Abstract. Bloodmeal digestion in midguts of the sandflies Phlebotomus papatasi and Phlebotomus langeroni (Diptera: Psychodidae) was investigated in optimized assays to detect general protease, trypsin and aminopeptidase activities using synthetic substrates. Optimal activity occurred at pH 8‐9 for all enzymes examined in both species. Protease activity peaked at 24‐34h post human bloodmeal in midguts of P.papatasi and 34‐48h in P'.langeroni; all endo‐ and exoprotease activities were completed by 50 h in P.papatasi compared to 72 h in P. langeroni. Hydrolysis of two chymotrypsin substrates was <2% of trypsin activity in both species. Aminopeptidase activity was associated mainly with the midgut wall, whereas trypsin activity was confined to the midgut lumen. A feature of digestion in P.langeroni was the high level of aminopeptidase recorded within 10h of the bloodmeal.
Scanning electron microscopy of the larval instars of Cochliomyia hominivorax
Authors: LEITE A. C. R. , GUEVARA J. D. E.
Published: March 2008

Abstract. Descriptions are given of the morphological features of laboratory‐reared first to third larval stages of Cochliomyia hominivorax. The pseudo‐cephalon, spines and papillae of the segments, and the anterior and posterior spiracles of all three larval stages were studied by scanning electron microscope microscope
Autumn southward ‘return’ migration of the mosquito Culex tritaeniorhynchus in China
Authors: JI‐GUANG MING , HUA JIN , RILEY J. R. , REYNOLDS D. R. , SMITH A. D. , REN‐LAI WANG , JI‐YI CHENG , XIA‐NIAN CHENG
Published: March 2008

Abstract. Direct evidence for a southward ‘return’ migration in autumn of the mosquito Culex tritaeniorhynchus in China was obtained by aerial sampling with a net suspended from a balloon. In a preliminary study between 2 and 20 September 1990 at Jiangpu, near Nanjing, in Jiangsu Province, 11 females and 4 males of this species were taken at heights of 150–250 m. During 17–26 October 1991 at Dongxiang in northern Jiangxi Province, 44 mosquitoes (8 males, 36 females) were caught in the aerial net at heights of 80–380m in northeasterly winds (E‐NNW). Most of the specimens were flying within the subsiding air‐mass behind a cold front. Cx tritaeniorhynchus was the only species identified (31 females) among the mosquitoes from Dongxiang. Of 24 females dissected, 17 had N stage ovaries — interpreted as diapause, five had stage I ovaries, one had stage II ovaries, and one was gravid (stage V), but none was freshly bloodfed. Cx tritaeniorhynchus is the main vector of Japanese viral encephalitis in China, and it is possible that the virus is reintroduced to northern temperate areas in spring by northward migration of infected Cx tritaeniorhynchus females.
Effects of adult body size on fecundity and the pre‐gravid rate of Anopheles gambiae females in Tanzania
Authors: LYIMO EDITH O. , TAKKEN W.
Published: March 2008

Abstract. The influence of adult body size on the pre‐gravid state and fecundity was studied in Anopheles gambiae Giles females hand‐caught inside houses and virgin females collected as pupae in Tanzania. Blood‐fed mosquitoes were kept for 2‐3 days before dissection and examination for insemination and ovarian condition. Those females which did not develop eggs were classified as pre‐gravid. The number of mature eggs in those mosquitoes which became gravid was counted. Virgin females were fed and kept for egg maturation in the laboratory. Wing‐length of females was measured as an index of mosquito size.

The overall pre‐gravid rate in the resting An. gambiae population was found to be 21% and, of these, 66% had been inseminated. In the virgin females the pre‐gravid rate was 92.6%. The mean wing‐length of wild females which became gravid was significantly larger than those which remained pre‐gravid. There was a positive correlation between fecundity and wing‐length. Smaller females tended to require two or three bloodmeals to facilitate completion of the first gonotrophic cycle. The critical size permitting oviposition from the first blood‐meal was a wing‐length of 3 mm.
Amplification of tick‐borne encephalitis virus infection during co‐feeding of ticks
Authors: LABUDA MILAN , DANIELOVA VLASTA , JONES LINDA D. , NUTTALL PATRICIA A.
Published: March 2008

Abstract.Following engorgement ofRhipicephalus appendiculatuslarvae on guinea‐pigs infected with tick‐borne encephalitis (TBE) virus, none of the engorged larvae or emergent nymphs contained detectable infectious virus. However, one of twelve pools, each containing three of the unfed nymphs, was positive when screened by polymerase chain reaction (PCR), indicating a low prevalence of TBE virus infection in the unfed nymphs. After engorgement of the nymphs on four uninfected guinea‐pigs, 19/24 (79%) fed nymphs from one guinea‐pig and 4/25 (16%) fed nymphs from a second guinea‐pig were infected; all the ticks examined from the other two guinea‐pigs were uninfected. The results suggest that TBE virus was transmitted from a low proportion of infected nymphs (infected as larvae) to uninfected nymphs as they fed together on an uninfected guinea‐pig. Such amplification of the initial infection, at the population level, could play an important role in maintaining TBE virus infections in nature, particularly if there is a low level of vertical transmission from one tick generation to the next.
Prevalence of Theileria in the tick Hyalomma detritum detritum in the Doukkala region, Morocco
Authors: FLACH E. J. , OUHELLI H. , WADDINGTON D. , HASNAOUI M. EL
Published: March 2008

Abstract. The overall prevalence of Theileria species, mainly, if not exclusively, T.annulata, in 901 Hyalomma detritum detritum collected from cattle in the Doukkala region of Morocco over a period of 2 years was 21.5%. The quantity of infection (number of sporoblasts per infected tick) followed the negative binomial distribution with between one and 250 sporoblasts per infected tick. Infected ticks were found in eight of fourteen areas examined whilst T.annulata was present in all fourteen. There were significant differences in both the prevalence and the quantity of infection between ticks collected from different farms, and between nymphs collected in the autumn from these farms, and moulted in the laboratory, and adults collected in the following summer. The prevalence, but not the quantity, of infection was higher in female than in male ticks. No correlations were established between infection of engorged nymphs and the breed, sex and Theileria piroplasm parasitaemia of the host animal. However, calves infected a greater proportion of nymphs than adult cattle and the heavier the infestation of nymphs on an animal, up to a plateau, the higher the prevalence of infection in those nymphs. There were no differences in infection between ticks moulted at 24oC and 37oC, after the engorged nymphs had been stored at 18oC to simulate over‐wintering.
Description and biology of Trichopria painteri n.sp. (Hymenoptera: Diapriidae), a solitary parasitoid of Stomoxys calcitrans (Diptera: Muscidae) from Harare, Zimbabwe
Authors: HUGGERT LARS , MORGAN PHILIP B.
Published: March 2008

Abstract. Taxonomic description and life history are given of Trichopria painteri n.sp. (Hymenoptera: Diapriidae), a solitary endoparasitoid that emerged from Stomo.xys calcitrans (L.) (Diptera: Muscidae) pupae collected at an agricultural installation near Harare. Zimbabwe. Africa. Although its low level of parasitism. high immature mortality and short adult life span would require augmentative releases of T. painteri. this parasitoid could reduce isolated field populations of S.calcitrans to an acceptable level within several weeks.
Description of the larva, diagnosis of the nymph and female based on scanning electron microscopy, hosts, and distribution of Ixodes (Ixodes) venezuelensis
Authors: DURDEN LANCE A. , KEIRANS JAMES E.
Published: March 2008

Abstract. The larva, nymph, and female of Ixodes (Ixodes) venezuelensis are diagnosed using scanning electron microscopy, and the larva is described for the first time. This ixodid tick is recorded from the northern neotropics as a parasite of five species of didelphid marsupials and eighteen species of rodents (one sciurid, two heteromyids, eleven murids, two dasyproctids, and two echimyids). Collection records of I. venezuelensis are presented for Costa Rica, Colombia, Panama and Venezuela, with the Costa Rican records being new and extending the known range of this tick by at least 300 km. Altitudinally, I. venezuelensis has been collected between elevations of 24 and 2410 m with most collections between 100 and 800m. The possibility that I. venezuelensis may be partheno‐genetic is discussed.
Comparisons of sampling methods and seasonal abundance of Drosophila repleta in caged‐layer poultry houses
Authors: HARRINGTON L. C. , AXTELL R. C.
Published: March 2008

Abstract. Four sampling methods were compared to determine their practicality and suitability for detecting population fluctuations of adult Drosophila repleta, a pest in caged‐layer poultry houses. Five caged‐layer poultry houses with gutter‐flush manure removal systems in Franklin County, North Carolina, U.S.A., were sampled once every 2 weeks over 15 months, from June 1991 to August 1992. The flies were most abundant during the spring and early summer. Visual counts of adult flies resting on the feed troughs in front of cages in the aisles and counts of flies caught on a sticky ribbon lowered into the gutter used for manure removal by flushing were more satisfactory sampling methods than using counts of flies caught on sticky ribbons carried along the aisles or aspirator collections from the gutters. For the visual count method, the effects of location in the house, within each aisle, and feed trough height were determined; two counts on feed troughs in each of two inside rows of cages were sufficient to measure population changes. For routine monitoring of D. repleta populations, visual counts of flies resting on the feed troughs in the front area of two aisles and catching flies on sticky ribbons inserted into the rear gutter area are recommended.
Population dynamics and density‐dependent seasonal mortality indices of the tick Rhipicephalus appendiculatus in eastern and southern Africa
Authors: RANDOLPH SARAH E.
Published: March 2008

Abstract. Eight sets of previously published data on the seasonal abundance of the tick Rhipicephalus appendiculatus in Burundi, Uganda, Tanzania and Zimbabwe are analysed to yield seasonal mortality indices. Correlations between these indices and abiotic (climatic) and biotic (tick density) variables suggest that it is the stage from females to larvae that is most sensitive to adverse abiotic conditions, specifically low moisture availability. Mortality at the other stages of the tick's life cycle is strongly density‐dependent. The precise nature of this density‐dependence suggests that it may be caused by acquired resistance to ticks by cattle. Robust correlations between satellite‐derived vegetation indices, climatic factors and mortality indices suggest that detailed climatic data, often unavailable, may be replaced by satellite data, now widely available, for use in modelling tick populations.
Antigens and glycoproteins of larvae, nymphs and adults of the tick Ixodes ricinus
Authors: UHLÍR J. , GRUBHOFFER L. , BORSKÝ I. , DUSBÁBEK F.
Published: March 2008

Abstract Protein components of homogenates of unfed larvae and nymphs of Ixodes ricinus (L.), and of ovary, haemolymph, Malpighian tubules, rectal ampulla, fat body, integument, salivary glands and midgut of partially fed adult females were studied for their antigenicity and carbohydrate moieties using immunoblotting and lectin affinity blotting (LAB) techniques. Comparing the individual anti‐larval, anti‐nymphal and anti‐adult immune sera for their capacity to recognize the specific and trans‐stadially cross‐reactive antigenic proteins, larval feeding induced the most effective humoral response. The majority of immunogens recognized by rabbit anti‐tick immune sera are glycoproteins. Most of the glycosylated antigens were modified with N‐type glycans; however, O‐type glycans were also demonstrated in some antigens. The correlation of the type of glycosylation with antigenicity, and the sharing of common antigenic epitopes by various tissues, are discussed.
An entomological investigation of the likely impact of cattle ownership on malaria in an Afghan refugee camp in the North West Frontier Province of Pakistan
Authors: HEWITT SEAN , KAMAL MUHAMMAD , MUHAMMAD NASIR , ROWLAND MARK
Published: March 2008

Abstract. Field trials were undertaken to determine the effect of close proximity of humans to livestock on the human biting rates exhibited by various anophelines. The results indicate that proximity to cattle and to goats increases the subject's chances of being bitten by anophelines. Man‐biting by Anopheles stephensi rose by 38% (8–68% CI) in the presence of a cow, and by 50% (16–84% CI) in the presence of two goats. Other species exhibited similar trends. These findings explain the results of an earlier trial which revealed that malaria prevalence was higher amongst families that kept cattle than those that did not.

The findings are discussed in relation to existing information regarding the host preferences of local anophelines and classic theories regarding zooprophylaxis. Our findings suggest that animals are only likely to have a worthwhile prophylactic affect when the vector is zoophilic, and then only when the animals are deployed to form a barrier between that vector and man. In situations where deployment of livestock to form a zoobarrier is impractical, the livestock should be located as far from man as possible.
Use of partially engorged female ticks as laboratory animals in microbiological research
Authors: ŘEHAČEK JOSEF , ŠU?ÁKOVÁ GABRIELA , KOCIANOVÁ ELENA
Published: March 2008

Abstract. Partially engorged female ticks were used as laboratory animals in microbiological research. The ticks, which were inoculated intracoelomally, became a convenient substrate for the detection of viruses, rickettsiae and protozoal parasites. This research concerned the isolation of newly recovered micro‐organisms, the study of development, structure and distribution of microbial agents in ticks, and the study of their interaction with other pathogens or symbionts during mixed infection in a tick body. The isolation and maintenance of Rickettsiella phytoseiuli, the organism not of tick‐borne origin, was achieved. For use in Central Europe the tick Dermacentor reticulatus is recommended for the above investigations.
Host finding, feeding patterns and evidence for a memorized home range of the mosquito Aedes cantans
Authors: RENSHAW M. , SERVICE M. W. , BIRLEY M. H.
Published: March 2008

Abstract. ELISA tests of Aedes cantans bloodmeals in woodland near Liverpool during 1989 and 1990, revealed preferences for sheep and cows, these hosts representing more than 60% of the total. Dispersal studies carried out on newly‐emerged adults and those caught at human bait, indicated that individuals move freely between the two woods studied, mixing as a single population. Mean recapture rates for mosquitoes marked with paint were 2.28% in 1989 and 6.3% in 1990. Recapture rates for mosquitoes marked with powder were 3.66% in 1989 and 6.25% in 1990. The patterns of dispersal of adult females suggest that Aedes cantans has a learned and memorized familiar area map and possesses a sense of location.
Arabian sandflies (Diptera: Psychodidae) prefer the hottest nights?
Authors: ROBERTS D. M.
Published: March 2008

Abstract. A vehicle‐mounted net was used to collect hourly samples of sandflies on 15 nights during June in northern Oman. Every half hour, the temperature, relative humidity, wind velocity and light intensity were measured (there was no cloud or rainfall during this period).

The sandflies caught were mainly Phlebotomus alexandri and Sergentomyia clydei. Their circadian activity increased rapidly after sunset (18.50 hours). The high level of activity was fairly constant during 9 h of darkness until dawn, when it decreased rapidly. A few flies were still active at 07.00 hours, 1.5 h after sunrise.

A multiple regression showed that the main factor affecting sandfly activity was light intensity. When this factor was removed, by considering only the 135 catches collected during the 9 h of darkness, the second most important factor was low relative humidity, followed by low wind velocity. Temperature was not a significant factor in the analysis, because of its strong negative correlation with humidity. However, when the effect of humidity was removed from the regression, high temperature became significant, but less important than wind.

The regressions showed that, for flight activity, the optimum humidity was around 10%; the probable maximum wind velocity was 3.5 ms‐1 and 11oC was the probable minimum temperature. Thus, when the 4 nights with highest catches (200–260 flies/night) were compared with the 4 nights with lowest catches (50–120 flies/night), the best nights had a low humidity (10–25%) and low wind speed (<0.3ms‐1) in combination with highest temperatures (31–43oC).
Vector competence of some Neotropical sandflies for the Leishmania (Viannia) braziliensis complex
Authors: JARAMILLO CONSUELO , TRAVI BRUNO L. , MONTOYA JAMES
Published: March 2008

Abstract. To evaluate the vector competence of some Lutzomyia spp. (Diptera: Psychodidae) for Leishmania (Viannia) spp. (Kinetoplastida: Trypanosoma‐tidae), experimental infections of anthropophilic sandflies from the Colombian Pacific coast were performed, through membrane feeding and xenodiagnosis on hamsters infected with Le.(V.)braziliensis or Le.(V.)panamensis. Wild‐caught or F, generation females of Lutzomyia gomezi, Lu.hartmanni, Lu.panamensis and Lu. trapidoi were allowed to feed on hamster lesions and then maintained at 26oC and >80% r.h. on a sugar‐water diet until dissection on the fifth day post‐infection (p.i.).

Despite similar infection rates (range 37–44%) in both Lu.gomezi and Lu.trapidoi, infections were heavier (>100 parasites) in the latter species. Infections of Lu.trapidoi with Le.braziliensis (n= 21) and Le.panamensis (n= 27) showed parasite migration toward the foregut, with promastigote colonization of the stomodeal valve and appearance of infective forms. In contrast, infections of Lu.gomezi with Le. braziliensis (n= 10) and Le.panamensis (n = 5) were light (<50 parasites) and usually restricted to the pylorus. In Lu.hartmanni, only a few promastigotes were found in the pylorus and midgut of 3/8 specimens infected with Le.braziliensis, and no Le.panamensis developed (n = 19). By day 5 p.i., promastigote colonization of the hind‐ and midgut by Le.panamensis was observed in 2/4 Lu.panamensis but not Le.braziliensis (n= 3).

It was concluded that Lu.trapidoi is a more efficient vector than Lu.gomezi for both Le.braziliensis and Le.panamensis, and that Lu.hartmanni and Lu.panamensis are of minor importance for Leishmania transmission in this endemic area.
Effects of physico‐chemical treatments on hemagglutination activity of Anopheles gambiae haemolymph and midgut extract
Authors: MOHAMED HASSAN A. , INGRAM GEORGE A.
Published: March 2008

Abstract. Anopheles gambiae midgut extracts and haemolymph possessed agglutinins, titre 1:16 to 1:256, against human red blood cells (RBCs). Subjection of both tissues to protein precipitation reagents, organic chemical and selected protease, neuraminidase and other glycosidic hydrolase treatments revealed the haemagglutinins to be protein, most likely glycoprotein, in nature ‐ not lipoprotein, lipid, glycolipid or nucleic acid. An.gambiae agglutinins were thermo‐labile >40oC, affected by freezing and thawing treatments, and contained disulphide and hydrogen bonds on the basis of sensitivity following exposure to dithio‐threitol and urea respectively. Optimum haemagglutination depended generally on slightly acid to neutral pH conditions and agglutinin activity was Ca2+ ion, albeit to a lesser extent Mg2+ ion, dependent. The midgut extract agglutinin subunit molecule had a relative molecular weight (Mr) of 65kDa whilst that of haemolymph was 40kDa.

This study presents the first report on selected physico‐chemical properties, the glycoproteinaceous nature and tentative subunit Mr of mosquito midgut extract and haemolymph anti‐RBC agglutinin(s).
Identification of bloodmeals of the Scottish biting midge, Culicoides impunctatus, by indirect enzyme‐linked immunosorbent assay (ELISA)
Authors: BLACKWELL A. , (LUNTZ) A. J. MORDUE , MORDUE W.
Published: March 2008

Abstract. An indirect enzyme‐linked immunosorbent assay (ELISA) has been developed to identify the bloodmeal sources of Culicoides impunctatus Goetghebuer. Nightly light trapping in Scotland, between April and September 1992, caught a total of 344 blood‐engorged female C. impunctatus, all in May, June and July. The insects were stored in 70% ethanol and tested 5–7 months later. Bloodmeal sources were positively identified for 246 (71.5%). Bovine hosts were most common (38.4%), followed by deer (23.0%) and sheep (9.9%). Only one midge had fed on human blood. Relatively freshly fed (<24h), fully engorged females gave the clearest results. The wider applications of the technique to the study of Culicoides host preferences is discussed.
Culicoides responses to 1‐octen‐3‐ol and carbon dioxide in salt marshes near Sea Island, Georgia, U.S.A.
Authors: KLINE DANIEL L. , HAGAN DANIEL V. , WOOD JOHN R.
Published: March 2008

Abstract. The semiochemicals carbon dioxide (CO2) and l‐octen‐3‐ol (octenol) were evaluated as attractants at several release rates, alone and in combination, for the major coastal species of biting midges in Georgia: Culicoides furens, C.hollensis and C.melleus (Diptera: Ceratopogonidae). The data show that CO2 is an effective attractant for the females of all three species, but each has a different response pattern. In contrast, octenol was an effective attractant only for C.furens, either alone or in combination with CO2; octenol had a repellent effect on the other two species. The combination of octenol and C02 had a synergistic effect on the collections of C.furens.
Anopheles culicifacies: effects of age on the male reproductive system and mating ability of virgin adult mosquitoes
Authors: MAHMOOD FARIDA , REISEN WILLIAM K.
Published: March 2008

Abstract.Under controlled laboratory conditions of 28–30oC and 16:8 L:D photoperiod, an attempt was made to develop an age‐grading technique forAnopheles culicifaciesmales. Mating activity was maximal when females were 5–12 days old and males were 5–7 days old. The numbers of total and mature spermatocysts declined significantly with age, and the proportion of the testes occupied by the sperm reservoir increased as virgin males grew older. Mating resulted in the loss of spermatozoa and accessory gland substance from the reproductive system. Loss of mating ability of older virgin males seemed to be age‐related, because the reproductive system contained ample supplies of accessory gland substance and spermatozoa. Morphological changes of the reproductive system, due to mating and age, were used to infer the age and reproductive history of unknown males in a laboratory evaluation.
Retention and attempted mechanical transmission of Ehrlichia risticii by Stomoxys calcitrans
Authors: BURG J. G. , NEELY D. M. B. , WILLIAMS N. M. , KNAPP F W.
Published: March 2008

Abstract.The ability of adultStomoxys calcitrans(L.) (Diptera: Muscidae) to retain viableEhrlichia risticii(Rickettsiaceae), the aetiologic agent of Potomac horse fever (PHF), and mechanically transmit the pathogen from citrated bovine blood artificially infected withE.risticiito susceptible mice was studied. ViableE. risticiiwere found in the digestive tract ofS.calcitrans3h after the flies had engorged to repletion on infected blood; however, noE. risticiiwere detected in flies ≥2 days after feeding. Subsequently, groups ofS.calcitranswere fed for 20 s on infected blood, then fed to repletion on mice 30, 60,130, 180 or 220 min after having feeding interrupted. Mice displayed no clinical signs of PHF and did not produce anti‐E. risticiiantibodies when assayed 30 days afterS. calcitranshad fed. AlthoughS.calcitranswere able to harbour viableE.risticiifor at least 3h, transmission of the disease agent to susceptible mice during interrupted feeding was not demonstrated under these experimental conditions.
Relationships between protease activity, host blood and infection rates in Glossina morsitans sspp. infected with Trypanosoma congolense, T.brucei and T.simiae
Authors: MIHOK STEVE , STILES JONATHAN K. , MPANGA ENOCH , OLUBAYO REARDON O.
Published: March 2008

Abstract. Midgut protease activity in Glossina morsitans centralis and G. m. morsitans, at 48h post bloodmeal averaged 1.8IU of trypsin‐like activity. These two tsetse subspecies differ in their susceptibility to trypanosome infection. Except for low levels in flies fed on waterbuck blood (0.7IU), activity did not differ in flies fed a variety of host bloods (goat, pig, cow, buffalo, eland) and trypanosome species (Trypanosoma congolense, T.brucei, T.simiae). Protease activity was also not correlated with infection rates, despite large differences in infection rates among experiments. Nevertheless, addition of 0.06M D(+)‐glucosamine to parasitaemic blood resulted in a three‐fold reduction in protease activity, coincident with a large increase in infection rate. This effect did not occur when parasites or D(+)‐glucosamine were added alone to the bloodmeal, suggesting that the effect was due to metabolism of D(+)‐glucosamine by parasites.
Differential responses of Aedes and Culex mosquitoes to octenol or light in combination with carbon dioxide in Queensland, Australia
Authors: ESSEN P. H. A. VAN , KEMME J. A. , RITCHIE S. A. , KAY B. H.
Published: March 2008

Abstract. Field studies were conducted with EVS (encephalitis vector surveillance) traps in south‐eastern Queensland, Australia, to determine the relative response rates of mosquitoes to three levels (0.1, 4.5 and 30mg/h) of 1‐octen‐3‐ol (octenol) in combination with a standard bait of 2200 g carbon dioxide (CO2), compared with CO2 alone or CO2 with light from a 6V incandescent bulb. Compared to CO2 alone, Aedes vigilax collections increased significantly when CO2 was supplemented by all three octenol emission levels, but not by the addition of light. Furthermore, the 4.5 and 30 mg/h release rate of octenol gave a significant increase in numbers of Ae.vigilax relative to that from CO2+ light. In contrast, collections of Culex annulirostris and Culex sitiens were not enhanced significantly by either the addition of light or octenol at all three levels. Fewer Cx sitiens were collected with octenol released at 4.5 mg/h in comparison to CO2 alone. These differential sampling rates should be taken into account when using EVS traps.
Nectar feeding by the early‐spring mosquito Aedes provocans
Authors: SMITH STEPHEN M. , GADAWSKI RANDY M.
Published: March 2008

Abstract. Nectar feeding by males and females of the mosquito Aedes provocans was studied at a site near Belleville, Ontario, Canada. Canada plum, Prunus nigra, and especially pin cherry, P. pensylvanica, bloomed contemporaneously with the emergence of Ae. provocans and were important nectar sources for adult mosquitoes during their first week of life. Blossoms of P. pensylvanica shielded for 24 h from foragers produced an average of 0.14 mg of sugar (≅ 2.3 J). This nectar was avidly sought by both sexes of Ae.provocans; > 97% of the blossoms were visited by mosquitoes in the first few days of blooming. Young adult mosquitoes were found on blossoms at all hours of the day and night; feeding on P. nigra was strongly eocrepuscular, whereas on P.pensylvanica feeding was much less strongly periodic. Adults foraged for nectar in an energy‐conserving, pedestrian strategy, devoting 56% (females) and 68% (males) of their time on blossoms to nectar feeding during foraging bouts that lasted a median of 5.3min. Both sexes sought nectar soon after emergence ‐ males before they had completed hypopygial rotation or swarmed, and females before mating or host seeking. Female Ae.provocans sought nectar in all stages of oogenesis, but primarily at the initiation of a gonotrophic cycle. Energy stores in the crop averaged 18 J per female, with a distribution that depended on gonotrophic age and parity.
Resistance to two organophosphorus insecticides in New Zealand populations of the Australian sheep blowfly, Lucilia cuprina
Authors: WILSON JOANNE A. , HEATH ALLEN C. G.
Published: March 2008

Abstract. A treated‐surface test was used in a bioassay to detect insecticide resistance to the organophosphorus compounds diazinon and propetamphos, in larvae of field strains of Lucilia cuprina in New Zealand during 1990/91 and 1991/92 (December‐April). Mean LC50s for both diazinon and propetamphos showed a significant increase between seasons although this is not necessarily indicative of a trend. Mean LC50s for diazinon increased from 1.16 to 1.60 mg/1 (P< 0.001) and for propetamphos from 0.49 to 0.59 mg/1 (P< 0.005) in pooled populations. Diazinon and propetamphos resistance was significantly correlated in both seasons, suggesting side‐resistance between the two insecticides.
Comparison of the predicted impact of a screwworm fly outbreak in Australia using a growth index model and a life‐cycle model
Authors: ATZENI M. G. , MAYER D. G. , SPRADBERY J. P. , ANAMAN K. A. , BUTLER D. G.
Published: March 2008

Abstract. The spatial population dynamics of an Old World screwworm fly, Chrysomya bezziana Villeneuve (OWS), outbreak in Australia have been modelled in two ways. The first model uses weekly growth indices derived from climatic data to predict the adult female population. The second is a detailed cohort life‐cycle model. Due to technical and time constraints, the growth index model is preferred as the biological component of a much larger bioeconomic model because of its smaller program size and faster execution. In deciding whether adoption of the growth index model would be at the expense of scientific accuracy, the life‐cycle model was developed as a yardstick. We showed that the growth index model was a practical and adequate substitution for the OWS life‐cycle model and a novel spatial/temporal modelling approach with generic qualities. We elaborate on the previously reported growth index model, describe the life‐cycle model and compare the results of both models. In the event of an OWS incursion in northern or eastern Australia, given average climatic conditions, both models predict that most of the suitable range (some 2.3M km2) will be colonized within 4–5 years if an eradication campaign is not attempted. Much of its permanent range would be in tropical and subtropical extensive grazing regions. Where computer or funding resources are restrictive, models incorporating growth indices may prove adequate for spatial population studies of some species.
Afrotropical Sarcophagidae in a carrion fly community
Authors: ASPOAS B. R.
Published: March 2008

Abstract. Collections of Afrotropical Sarcophagidae were made at a single locality. Seventeen species in two genera were found: Heteronychia with two species, and Sarcophaga with fifteen species. All male flies were identified, together with a few females, wherever possible. The number of male flies collected exceeded that of females. A small proportion of females captured were gravid.
Antibodies to Anopheles midgut reduce vector competence for Plasmodium vivax malaria
Authors: SRIKRISHNARAJ K. ALAGARATNAM , RAMASAMY RANJAN , RAMASAMY MANTHRI S.
Published: March 2008

Anopheles tessellatus mosquitoes ingested Plasmodium vivax gametocytes in human erythrocytes suspended in rabbit sera with and without anti‐mosquito midgut antibodies. When the mosquito bloodmeal contained anti‐midgut antibodies, fewer oocysts of P. vivax developed on the mosquito midgut and the proportion of mosquitoes becoming infected was significantly reduced. Complement inactivated serum also reduced the infection rate and load. A second bloodmeal containing anti‐midgut antibodies, given 48 or 72 h later, did not enhance the transmission‐blocking effect. IgG purified from antimidgut sera was shown to mediate the transmission‐blocking effect.
Efficacy of etofenprox against insecticide susceptible and resistant mosquito strains containing characterized resistance mechanisms
Authors: HEMINGWAY JANET
Published: March 2008

tofenprox is a non‐ester pyrethroid insecticide with comparable toxicity and a similar mode of action to other pyrethroids. Cross‐resistance studies on mosquitoes showed no effect of carboxylesterase, elevated esterase, altered acetylcholinesterase or glutathione S‐transferase‐based resistance mechanisms on etofenprox toxicity, when compared to standard susceptible strains of Anopheles and Culex. Cross‐resistance to etofenprox occurred in a pyrethroid‐resistant strain of Culex quinquefasciatus with both oxidase and ‘kdr’‐like resistance mechanisms.

Dose–response data for susceptible mosquito strains suggest that, in standard W.H.O. susceptibility tests of adult mosquitoes, appropriate discriminating concentrations of etofenprox for detection of resistance would be 0.1% for Culex and 0.25% for Anopheles.
Detection of Plasmodium sporozoites in mosquitoes by polymerase chain reaction and oligonucleotide rDNA probe, without dissection of the salivary glands
Authors: STOFFELS J. A. W. , LEEUWEN W. M. DOCTERS VAN , POST R. J.
Published: March 2008

Dried Anopheles gambiae mosquito head + thorax portions, infected with Plasmodium falciparum sporozoites, were processed by the polymerase chain reaction. The PCR product was hybridized to an oligonucleotide probe (known as 114R or AW34) diagnostic for Plasmodium. The detection level by autoradiography was ten sporozoites per mosquito. Head + thorax of mosquitoes that contained mature P.falciparum oocysts, without sporozoites, gave no positive signal, indicating that the test detects only infective mosquitoes. This test can be applied to wild mosquito specimens collected, prepared and processed at different time intervals. The technique is convenient, highly sensitive, and could be used with a non‐radioactive detection system and specific probes to differentiate Plasmodium spp.
Ovariolar ‘basal body’ development and physiological age of the mosquito Aedes aegypti
Authors: HOC T. Q. , SCHAUB G. A.
Published: March 2008

Abstract. Dissection of the ovaries of the mosquito Aedes aegypti (Diptera: Culicidae) revealed, in each ovariole, a group of seven to nine specialized epithelial cells in a region of the calyx wall that is enclosed by the end of the ovariolar sheath. This group of cells is termed the basal body. During ovulation, the mature oocyte passes from the ovariole into the calyx lumen through the basal body. Subsequently, granulation occurs in the basal body cells. The granular basal bodies differ from all previously described ovarian structures. In multiparous females the size and optical density of the granular basal bodies increase after each ovulation. Examination of the granular basal bodies in intact ovaries, stained with neutral red, provides an easy method for distinguishing parous from nulliparous females, and has potential as a new method of age grading.
Exposure of Gambian children to Anopheles gambiae malaria vectors in an irrigated rice production area
Authors: LINDSAY S. W. , SCHELLENBERG J. R. M. ARMSTRONG , ZEILER H. A. , DALY R. J. , SALUM F. M. , WILKINS H. A.
Published: March 2008

Abstract. Variation in exposure of children to malaria vectors of the Anopheles gambiae complex was recorded in a Gambian village situated near an irrigated area of rice cultivation. Observations were made in 1987 and 1988 during two dry seasons, when pumped water was used to grow rice, and two rainy seasons, when rice was produced using a combination of irrigated and rainfed paddies. Routine collections of mosquitoes were made from under bednets. Most of these specimens were assumed to have fed on the occupants of the net and thus represented a crude measure of exposure to malaria. Most nets in the village were in good condition, but even these were a poor defence against blood‐seeking mosquitoes.

Two annual peaks in the numbers of An. gambiae s.l. corresponded with the irrigation of rice paddies in the dry and wet seasons. When there were few vectors in the village the frequency distribution of mosquitoes caught under nets was described best by a Poisson process. When high numbers were present the daily distributions were over‐dispersed and fitted a negative binomial model. The spatial distribution of mosquitoes varied between dry and wet seasons and was related to the predominant wind direction at night, suggesting that wind assisted the dispersal of mosquitoes from their breeding sites.

For individual children in the rainy season, increased exposure to malaria vectors was associated with living adjacent to a mosquito breeding site, being resident in larger compounds, having open eaves in the house, a store‐room adjacent to the bedroom, the absence of a ceiling in the bedroom, the absence of wood smoke indoors and leaving the bednet untucked at night. In the dry season a high level of exposure was associated with living close to a mosquito breeding site, having an unfenced compound, sleeping in a room without a ceiling and using insecticide aerosols. These observations demonstrate that within a village there are systematic and persistent differences in the level of exposure to malaria parasites experienced by individual children.
Pyrethroid resistance in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis
Authors: LEVOT G. W. , JOHNSON P. W. , HUGHES P. B. , POWIS K. J. , BORAY J. C. , DAWSON K. L.
Published: March 2008

Abstract. Synthetic pyrethroid (SP) resistance has developed in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis. Laboratory bioassays were used to measure the susceptibility of lice to cypermethrin and the other registered SPs. Results of these bioassays indicated resistance to cypermethrin, deltamethrin, cyhalothrin and alphacypermethrin. So far, high‐level resistance has been diagnosed in only a few strains. The toxicological responses of these strains were clearly separated from those of the majority of louse strains tested. Furthermore, these strains had survived immersion in commercial SP dips. The level of resistance described in some strains was sufficient to cause pour‐on products to fail despite the fact that the LC50s of these strains fell within the normal range of field responses.
The effect of female body size on male mounting behaviour in Dermacentor variabilis and D. andersoni
Authors: HAMILTON J. G. C. , SONENSHINE D. E.
Published: March 2008

Abstract. This study was undertaken to determine if body size of female ticks was an important factor in eliciting the mating behaviour of Dermacentor variabilis and D. andersoni males. Dummy female ticks (DFTs) representing varying sizes of feeding females were prepared from plastic beads. Size of DFT was shown to be important in determining both the time spent by males in contact with DFTs and the extent of male mating response released. Dermacentor varlabilis males preferred the smaller‐sized DFT, whereas D. andersoni males preferred the larger sizes. Males of both species were able to discriminate between size of DFT only when mounting sex pheromone (MSP) was present.

Size of the DFT was more important than the composition of the MSP extract in determining the time males spent in contact with DFTs.

Males of both species were sensitive to variations in concentration of extract, and spent 2–6 times longer in contact with DFTs when the concentration was optimal than when it was not. No significant difference in the male's mating response was seen in response to variation in concentration of heterospecific extract.

Male mating response, i.e. the behaviour of the male as it progresses through the initial contact, climbing onto the dorsal surface and turning onto the venter, was shown not to be dependent upon how long the male spent in contact with the DFT. Male D. andersoni had a much lower mating response to DFTs than D. variabilis males, suggesting that some further stimulus may be required.
Comparison of sampling anopheline mosquitoes by light‐trap and human‐bait collections indoors at Bagamoyo, Tanzania
Authors: DAVIS JONATHAN R. , HALL THOMAS , CHEE ELSBETH M. , MAJALA AHMED , MINJAS JAPHET , SHIFF CLIVE J.
Published: March 2008

Abstract. The mosquito sampling efficiency of CDC miniature light‐traps, relative to night‐biting collections, was evaluated indoors at two sites in coastal Tanzania. We found that the total number of anophelines captured overnight by light‐traps (hung beside a bednet in use) was 1.23 times the number of anophelines captured by human‐bait collections. This relationship was not affected significantly by changes in the mosquito density, order of trapping method, date of sampling, or number of household occupants. Malaria sporozoite rates were twice as high among mosquitoes captured by light‐trap as compared to those captured by night‐biting collection. This was attributed to the tendency of light‐traps to capture a larger proportion of gravid mosquitoes, which also had high sporozoite rates. The differences in sporozoites rates according to abdominal stage indicates that unfed mosquitoes captured by light‐traps may define more precisely the human‐biting activity and sporozoite rates as seen by night‐biting collections. Our study shows that light‐traps, when used in combination with night‐biting collections, can be an effective and sensitive means for measuring human‐biting activity and the sporozoite rate.
Malaria infection potential of anopheline mosquitoes sampled by light trapping indoors in coastal Tanzanian villages
Authors: SHIFF C. J. , MINJAS J. N. , HALL T. , HUNT R. H. , LYIMO S. , DAVIS J. R.
Published: March 2008

Abstract. Anopheline mosquito populations were studied during 1992 in seven villages south of Bagamoyo, coastal Tanzania, prior to malaria control intervention using insecticide treated bednets. To collect mosquitoes, CDC light traps were used in ten houses per village fortnightly for 12 months. Anopheles females were identified and checked by ELISA for the presence of malaria sporozoite antigen and source of bloodmeal. An. funestus peaked in June‐July after the long rains. Three members of the An. gambiae complex had different seasonality: An. arabiensis, An. gambiae and small numbers of An. merus were collected.

In most villages transmission was extremely high and perennial with the entomological inoculation rate reaching three to eleven infective bites per person per night in July and persisting at around 0.1 and 1 for most of the remainder of the year. Sporozoite infection rates within the An. gambiae complex ranged from 2% to 25%, with the peaks in January and July following the two rainy periods. An. funestus showed a similar pattern. The light traps were reliable, simple to operate, and proved to be satisfactory to study the mosquito vector population.
Sugar meal sources for the phlebotomine sandfly Lutzomyia longipalpis in Ceará State, Brazil
Authors: CAMERON M. M. , PESSOA F. A. C. , VASCONCELOS A. W. , WARD R. D.
Published: March 2008

Abstract. In the Brazilian village of BoqueiraTo do Renato Parente, Ceará State, where visceral leishmaniasis is endemic, significant variation in the abundance of phlebotomine sandflies between different types of vegetation was demonstrated by castor oil sticky trap collections. Population densities of Lutzomyia longipalpis (Lutz & Neiva) sandflies were higher in beans and maize crops than in the surrounding open and tree scrub. Significant relationships were detected between the abundances of sandflies and aphids, suggesting aphid honey dew as a potential food source. Sugar meal analysis, using high‐performance anion exchange (HPAE) chromatography with pulsed amperometric detection (PAD) and the cold anthrone test, was used to demonstrate that significantly more sandflies fed on bean plants contaminated with aphids and honeydew than on uncontaminated beans. Furthermore, higher concentrations of sugars were detected in flies which fed on aphid/honeydew‐contaminated beans, suggesting that sugar was more easily available and/or that honeydew/aphids act as phagostimulants for sandflies. Amongst wild sandflies collected from a bean field, significantly more female sandflies were ‘sugar‐positive’ than males, though the sugar concentrations in positive sandflies were similar for both sexes. The concentrations of di‐ and trisaccharides in sandfly homogenates, honeydew extracts and phloem exudates were very low.
Laboratory evaluation of desiccants and insecticidal soap applied to various substrates to control the deer tick Ixodes scapularis
Authors: PATRICAN LISA A. , ALLAN SANDRA A.
Published: March 2008

Abstract. Desiccant and soap pest control products were tested against Ixodes scapularis nymphs on sod, pachysandra, landscaping stones and pinebark wood‐chips in a laboratory study. High mortality (91–100%) was obtained with the silica‐based desiccant Drione and Safer's insecticidal soap (SIS) treatments except for SIS treated woodchips. SIS and Drione contain 0.2 and 1% pyrethrins, respectively. SIS may be absorbed by the woodchips and not picked up by the nymphs as mortality decreased to 78%. Diatomaceous earth and Dri‐die reduced nymphs by only 10–41%; neither desiccant contains insecticides. Nymphal mortality increased 15–17% after 20 or 100 ml of water was sprayed over sod plugs treated with SIS or Drione. The addition of isopropyl alcohol (ROH) to SIS increased the efficacy of SIS against nymphal I. scapularis on treated sod plugs but not on treated landscaping substrates. Drione, SIS, SIS‐ROH and chlorpyrifos 50WP treated landscaping stones and pinebark woodchips resulted in 88–95% and 72–96% nymphal mortality, respectively. Unexpectedly, these substrates and treatments affected tick movement as well. Effective pest control products applied to xeric landscaping substrates present in maintained beds and borders near wooded areas could deter tick movement and provide significant levels of tick control.