bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on the Cotton Bollworm, Heliothis armigera, Hübn. (obsoleta, Fabr.)
Authors: Parsons F. S.
Published: July 2009

Egg Parasites.—In the Eastern Transvaal, Swaziland and Natal the eggs of Heliothis armigera are parasitized by Trichogramma luteum, Gir., and Telenomus (Phanurus) ullyetti, Nixon. No other egg parasites have been encountered.

Representative samples of eggs were collected weekly or twice-weekly over a period of seven years and over wide areas from the various cultivated crops and colonies of wild food-plants which exemplify the annual chain of breeding sites of H. armigera. The collected eggs were incubated to determine the “active” fraction derived after withdrawal of the infertile portion and of eggs exposed for less than 24 hours to parasite action. Observed parasitism was computed against the “active” eggs and is regarded as an index of the parasitism in the field. Running indices of this nature are given graphically to indicate the annual incidence of egg parasitism in percentages, which may be viewed in relation to the incidence of bollworm as evinced by oviposition data in the figures given. Sustained high levels of parasitism are associated mainly with the more abundant egg populations on winter-irrigated vegetable crops grown between July and November.

It has been found that Telenomus occurs mainly in the period August to December, and Trichogramma in the period December to March–April. The high parasitism of the winter egg populations is due, therefore, almost solely to Telenomus.

Evidence is submitted that the levels of parasitism in certain crops are commonly much higher than in others. Explanations are suggested by consideration of sites of egg deposition, accessibility of eggs, plant habit, vegetative and flowering, and, particularly, the known oviposition-flowering relationship of Heliothis moths. The latter has an important bearing on the persistence of host material and governs opportunity for the intervention of parasite progeny in increasing numbers.

Records on the status of egg parasitism have been taken in conjunction with investigations of the extent of larval mortality associated with the various types of crop. The rôle of egg parasites as agents reducing the issue of moths from winter and spring breeding areas is discussed briefly. Comparisons are given to show that the influence wielded is inappreciable even in some cases where parasitism is particularly high.
A new Mealy Bug attacking Pineapple Plants in Mauritius
Authors: Mamet Raymond
Published: July 2009

The pineapple plantations of Mauritius have sustained since 1937 severe attacks of mealybugs (Pseudococcus spp.) which threatened to ruin the whole crop in certain localities. These attacks result in a wilting of the plants, which may be due to a toxin secreted by the bugs during their process of feeding.
New Braconid Parasites ofAntestia lineaticollis, Stål, and ofSylepta derogata, F.
Authors: Nixon G. E. J.
Published: July 2009

In this paper a short revision of the African forms of the genusAridelus(formerlyHelorimorpha) is given and one new species is described. Of the seven African species now known (some of which will almost certainly fall later as synonyms) three, including the new one, are parasites of the important Hemipterous pest of coffee,Antestia lineaticollis, Stål.
Progress of the Control of Coconut-feeding Coccidae in Seychelles
Authors: Vesey-Fitzgerald Desmond
Published: July 2009

Since writing my report on the establishment and work of certain predators on coconut-feeding scale-insects in Seychelles (Bull. Ent. Res., 31, 1940, pp. 253–283) some further records of their progress have been received. These records were taken by Mr. A. Michel under the direction of the Director of Agriculture of Seychelles, to whom I am indebted for the figures. The sampling was carried out in 10 of the localities sampled previously, so that the 1940 figures represent the fourth yearly count in each of these localities. The first count in 1937 was made before the predators had been liberated, while the subsequent counts show the yearly progress in scale reduction which has been achieved since they have been active.
The sensory receptors of the carrot fly larva, Psila rosae (F.) (Dipt., Psilidae)
Authors: Ryan M. F. , Behan M.
Published: July 2009

Examination of the cephalic lobes of larvae of Psila rosae (F.) by means of light and scanning electron microscopes revealed the presence of 24 sensilla, ten campaniform, eight basiconic, four ampullaceous and two styloconic. By comparison with the known functions of similar sensilla in other insects, it is suggested that the ampullaceous and basiconic sensilla respond to plant emanations in soil, air and water, respectively, and that styloconic sensilla determine the palatability of the root hairs; the role of the campaniform sensilla is obscure.
The significance of moonlight in photoperiodic responses of insects
Authors: Bowden John
Published: July 2009

In the tropics, the amount and the pattern of distribution of moonlight at and just after full moon produces alternating periods of continuous illumination and darkness which could provide photoperiodic cues for insects. Examples of possible photoperiodic effects induced by moonlight, taken from the published literature, include the flight activity and oviposition patterns shown by females of Heliothis zea (Boddie) and Diatraea saccharalis (F.) and crepuscular activity of mosquitoes. It is suggested that photoperiodic responses to moonlight could form the basis for a simple method of predicting such events.
The Use of Carbon Dioxide Production as a Measure of Infestation of Grain by Insects
Authors: Howe R. W. , Oxley T. A.
Published: July 2009

1. A detailed technique is described for the routine determination of the carbon dioxide output of samples of grain. The concentration of carbon dioxide produced in the intergranular air during incubation for 24 hours at 25°C. is known as the “carbon dioxide figure” of the sample.

2. Suggestions for relating the carbon dioxide figure to potentialities for future storage are given. A high carbon dioxide figure indicates that the grain is unsuitable for storage.

3. The carbon dioxide figure is largely a measure of insect infestation of the sample and a table is given by which the numbers of various species of insects common in grain may be estimated from the carbon dioxide figure.

4. Theoretical considerations affecting the carbon dioxide figure are discussed as far as available knowledge permits.

5. Data obtained in the laboratory during development of the method are presented, and show it to give a useful measure of the amount of infestation.

This work forms part of the programme of the Pest Infestation Laboratory. Thanks are due to Dr. Lucas for making an independent test of the method and for allowing us to use his data.
The effect of resource limitation on competing populations of flour beetles,triboliumspp. (Coleoptera, Tenebrionidae)
Authors: Nathanson Michael
Published: July 2009

Single-species and mixed-species populations ofTribolium castaneum(Hbst.) andT. confusumDuv. were followed in two experiments. Food (flour) was renewed at various intervals between 30 days and 180 days or was not renewed at all. As the interval between food renewals lengthened, single-species populations ofT. confusumbecame extinct later than populations ofT. castaneum, the survivor in mixed-species populations changed fromT. castaneumtoT. confusum, and the mixed-species populations became extinct later than the single-species populations. When resource is limited, therefore, populations of the two species may persist longer if they compete than if they are husbanded as single species.
Life-history and larviparous reproduction of musca fergusoni J. & B. (Diptera, Muscidae)
Authors: Ferrar P.
Published: July 2009

Musca fergusoni J. & B. is an indigenous Australian fly that infests livestock, feeding on sweat and other body secretions and breeding in cow and horse dung. The fly is larviparous, developing a single larva at a time and depositing it at the end of the first instar. The ovaries comprise two ovarioles each, and the single ovulations alternate between ovaries and between ovarioles within an ovary. Abnormalities of development shown by unfertilised females are described, including the accumulation of fluid around unhatched eggs in the uterus which suggests that there is intrauterine secretion of nourishment for the larva. Descriptions are given of the immature stages. The egg is adapted for life in utero by having the respiratory plastron confined to the posterior end, oriented towards the genital aperture of the mother. The puparium is whitish, and is hardened by calcification instead of tanning. The durations of development at 16, 20, 27 and 32°C are given: from larval deposition to moult to third instar takes 58, 38, 19 and 15 h, respectively; from larval deposition to pupariation 11·5, 7·5, 3·5–4 and 3–3·5 days, respectively; and from larval deposition to adult emergence 53–57, 31–33, 15·5–16·5, and 10–11 days, respectively.
The taxonomic status of the carob gall midge,Asphondylia gennadii(Marchal), comb. n. (Diptera, Cecidomyiidae), and of otherAsphondyliaspecies recorded from Cyprus
Authors: Harris K. M.
Published: July 2009

The carob gall midge, previously known asEumarchalia gennadii(Marchal), is formally assigned toAsphondyliaH. Loew, andEumarchaliaDel Guercio is synonymised withAsphondylia. Specimens ofAsphondyliareared from pod galls on carob (Ceratonia siliqua) during biological research by G. M. Orphanides in Cyprus seem to be morphologically indistinguishable from specimens reared by him from galls onCapsicum annuum, Capparis spinosa, Urginea maritima, Asphodelus fistulosus, Solanum tuberosum, Hypericum crispumandSinapisspp. Possible reasons for this unusually wide host range of the carob midge are discussed with particular reference to the occurrence of ambrosia fungi in galls of the genusAsphondylia. Gall midges reared fromVerbascum sinuatumin Cyprus are morphologically distinct fromA. gennadiiand are identified asA. verbasci(Vallot). Characters separating these two species are illustrated and tabulated.
Field and laboratory experiments on the site of oviposition by the potato mothPhthorimaea operculella(Zell.) (Lepidoptera, Gelechiidae)
Authors: Traynier R. M. M.
Published: July 2009

Counts of first-instar larvae showed that in a potato plot near Canberra, A.C.T., eggs ofPhthorimaea operculella(Zell.) were more prevalent around the bases of plants than between the rows or 2 m outside the plot; the few eggs on the plants were on dead leaves. In small plots each of different plant species, with due allowance for predation, many eggs were laid around tobacco and potato, and few or none near tomato, maize, lettuce or pea. Older larvae were most numerous on tobacco plants, while adults were most numerous on potato plants. A series of laboratory experiments using different oviposition substrates showed that the factors favouring oviposition could be ranked, in descending order: coarse substrate, shade, and treatment of the substrate with juices of potato tubers or foliage; foliage of potato or tobacco was not preferred.
Effect of temperature and photoperiod on diapause induction inErioischia brassicae(Bch.) (Diptera, anthomyiidae) under controlled conditions
Authors: Soni S. K.
Published: July 2009

Experiments were carried out to determine the optimum temperatures and photoperiods for inducing diapause in the cabbage root fly,Erioischia brassicae(Bch.). The induction of diapause occurred at certain receptive stages between the first and third instars of larval development. When developing larvae were subjected to 20±1°C and a 16-h photoperiod for 7–14 days followed by 13±0·5°C and a 10-h photoperiod for 28–35 days, diapause was induced in 84–97% of the pupae; 88–99% of pupae entered diapause when developing larvae were subjected to 13±0·5°C and a 10-h photoperiod for 28–42 days followed by 20±1°C and a 16-h photoperiod for 11–18 days. Similar results were obtained when developing larvae were subjected to 13±0·5°C (day)/7±0·5°C (night) and a 6-h photoperiod. The fecundity of flies from the diapausing pupae was not adversely affected. Application of these results should enable cabbage root fly to be cultured economically for intermittent use.
Field studies with the synthetic sex pheromone and inhibitor of the red bollworm Diparopsis castanea Hmps. (Lepidoptera, Noctuidae) in Malawi
Authors: Marks R. J.
Published: July 2009

The synthetic sex pheromone of Diparopsis castanea Hmps., dicastalure, is a 4:1 synergistic combination of 93% trans:7% cis-9,11-dodecadien-1-yl acetate (IV) and the unattractive compound 11-dodecen-1-yl acetate (IIB). Both cis and trans-9-dodecen-1-yl acetate (IIA), the latter occurring in the female pheromone gland, are potent inhibitors of male attraction, as little as 10–4 mg IIA significantly reducing the attractiveness of virgin females in pheromone traps for more than one month in the field. Inhibition is typically close range, although higher concentrations are inhibitory when placed at up to 1 m from the female. IV and IIB also reduce male catch in female-baited traps, but dicastalure does not. Recently mated females, confined with virgins, reduce male catch, thereby indicating release of an unknown inhibitor. When formulated in a suitable extender, such as corn-oil, dicastalure may be released from sealed polyethylene vials or from cellulose acetate cigarette filters, and inclusion of the antioxidant 2:6-di-tort-butyl-p-cresol (BHT) prolongs the attractiveness of 1 mg dicastalure formulations beyond 25–30 days. Release from polyethylene is more efficient than from either polypropylene or cellulose and moth catch over a five-week period is linearly related to the logarithm of pheromone concentration. Significant communication disruption, as measured by reduced trap catches of male Diparopsis, occurred when female-baited traps in 100 m2 cotton plots were surrounded by point sources of either dicastalure (synthetic females) or the inhibitory IIA acetate (anti-females). Since dicastalure is occasionally less attractive than virgin females, efforts are being made to improve pheromone slow release formulations.
Ecological studies of ixodid ticks (Acari, Ixodidae) in Zambia. II. Ticks found on small mammals and birds
Authors: Colbo M. H. , MacLeod J.
Published: July 2009

Ticks were collected from 2136 small mammals, comprising 5 bats (5 species), 14 elephant shrews (3 species), 84 Crocidura shrews (5 species), 25 hares (1 species), 10 small carnivores (3 species), 3 hyraxes (1 species) 1998 rodents (33 species), and from 41 birds (19 species) at various localities in Zambia. From these hosts 6568 ticks (4384 larvae, 1686 nymphs, 317 males and 181 females) were recovered. Twenty-three species were positively identified and nineteen other species were assigned to genus or species-group. Host and tick records are tabulated by regions collected and for each of the two regions with the largest collections, the records are tabulated by months. The ticks collected in the high montane area near the Malawi border differed significantly from collections in other areas studied, reflecting host and climate differences. In the two areas tabulated by month, most of the immature ticks were recovered in the cool dry winter months (April to August).
The effect of genotype, environment, age and morph on morphological variation in alate Myzus persicae (Sulzer) (Hemiptera: Aphididae)
Authors: Woodford J. A. T. , Lerman P. M.
Published: July 2009

Six morphological variates were examined in fundatrigeniae and alienicolae of Myzus persicae (Sulz.) from four clones. In all clones, fundatrigeniae had significantly more abdominal tubercles, a relatively larger tubercle on segment 4, and relatively shorter cornicles than did alienicolae. Alienicolae reared on Chinese cabbage had significantly shorter hind femurs than those reared on potato, but otherwise there were no consistent differences between the two types. Mature fundatrigeniae did not differ consistently from young ones. The total number of abdominal tubercles was the most reliable character for distinguishing alate fundatrigeniae from alienicolae.
Observations on the specificity of pheromone-baited traps for Cydia funebrana (Treitschke) (Lepidoptera: Tortricidae)
Authors: Alford D. V.
Published: July 2009

Sticky traps baited with (Funemone cis-8-dodecenyl acetate or (Codlemone trans-8,trans-10 dodecadien-1-ol) were operated in plum orchards in Cambridgeshire, England, from 1974 to 1976. In addition to large numbers of the target species Cydia funebrana (Treitschke), males of 24 other tortricids were captured. These included species of Cnephasia, Celypha, Epiblema, Pammene and Cydia. As an aid to the correct identification and interpretation of trap catches, details are given of the more important species attracted by the pheromone baits.
The abundance and inter-specific relations of common ant species (Hymenoptera: Formicidae) on cocoa farms in western Nigeria
Authors: Taylor Brian , Adedoyin S. F.
Published: July 2009

Following a demonstration of the role of ants in the dissemination of Phytophthora pod rot and an intensive study of the ant mosaic on cocoa at the Cocoa Research Institute of Nigeria, there was a need for a wide-scale assessment of the relative importance of different species of ant on cocoa farms in the major growing area of western Nigeria. Between 19 January and 6 February 1976, 50 trees were examined on each of 76 cocoa farms and all ant species visible from the ground were recorded. Sixteen species, or species-groups, of ants occurred on more than 1% of the trees, and their geographical distribution, habitat requirements and inter-specific relations were examined. The last of these were elucidated using principal components analysis, and the results are compared with earlier work on the ant mosiac. Any one cocoa farm only rarely provided a suitable habitat for more than one or two of the dominant species, and a diagram summarising the habitats is given. The potential usefulness of ant population manipulation is thought to be restricted in Nigeria by the undesirable effects of co-dominant and associated species found with the dominant species, Oecophylla longinoda (Latr.) and Tetramorium aculeatum (Mayr), which are regarded as beneficial in Ghana. The most important of the undesirable co-dominants is Pheidole megacephala (F.).
Rearing triatomine bugs in the absence of a live host and some effects of diet on reproduction in Rhodnius prolixus Stål (Hemiptera: Reduviidae)
Authors: Langley P. A. , Pimley R. W.
Published: July 2009

Rhodnius prolixus Stȧl was successfully reared for three generations on a diet of defibrinated pig blood fed through Parafilm or silicone-rubber membranes. Reproduction in terms of the number and sizes of eggs produced was superior to, while survival from egg to adult was equal to that reported for, insects fed on live hosts. The technique appears equally applicable to the rearing of Panstrongylus megistus (Burm.), Triatoma infestans (Klug) and T. brasiliensis Neiva. The inadequacy of cow blood as a diet for R. prolixus was manifested in a decrease in adult size after two generations and in a reduction of egg weight from 30 to around 16 mg per female per week. This was accompanied by a corresponding reduction in egg hatch from 90 to about 50%.
Defence mechanisms in young and old leaves against cutting by the leaf-cutting antsAtta cephalotes(L.) andAcromyrmex octospinosus(Reich) (Hymenoptera: Formicidae)
Authors: Littledyke M. , Cherrett J. M.
Published: July 2009

In laboratory colonies ofAtta cephalotes(L.) andAcromyrmex octospinosus(Reich), discs cut from young leaves of several plant species were picked up more readily than those from old leaves. Pith sections impregnated with whole extracts of young leaves were consistently picked up in preference to others with extracts of old leaves, and non-lipid extracts were consistently preferred to extracts containing lipids. Arrestive properties were confined to the non-lipid extracts, and inhibitory properties were mainly found in the lipids, but removal of lipids from the whole extracts did not necessarily make them more arrestive. In most cases, dewaxing of leaves with chloroform made them more acceptable, and heating and freezing of leaves had a similar effect. Leaf waxes showed inhibitory properties. Wax extract of young leaves was often preferred to that of old leaves, and differences in preferences were observed for wax extracts from different plant species. The implications of these findings for the relationship between leaf-cutting ants and the vegetation that they cut are discussed.
Distribution of Glossina (Diptera: Glossinidae) in south-western Ethiopia
Authors: Fuller G. K.
Published: July 2009

Glossina spp. were collected in south-western Ethiopia and were found to have a continuous distribution from the Sobat River Basin to the southern Rift Valley lakes of Chamo and Abaya. Their limits to the north and east of this range was not determined. Along the Omo River, Glossina inhabit a continuous band from 20 km above Lake Rudolf to at least as far as Abelti, 167 km south-west of Addis Ababa. The species collected were G. pallidipes Aust., G. fuscipes Newst., G. morsitans submorsitans Newst. and G. Iongipennis Corti. The ratio and numbers of G. pallidipes and G. fuscipes suggest a relationship between the latter and the number of hippopotamus along the Omo River. Both G. pallidipes and G. Iongipennis were caught biting at night.
Persistence and migration of Chortoicetes terminifera (Walker) (Orthoptera: Acrididae) in Australia
Authors: Symmons P. M. , McCulloch L.
Published: July 2009

Examples of the persistence of adult infestations of Chortoicetes terminifera (Wlk.) in Australia were contrasted with ones where mass displacement took place. Migration occurred if sufficient rain had fallen at the nymphal stage to produce green pasture; persistence was associated with drought.
Excretory behaviour in soft scales (Hemiptera: Coccidae)
Authors: Williams J. R. , Williams D. J.
Published: July 2009

The liquid excrement of many Homoptera, which often accumulates as honeydew, can be harmful to the insects that produce it. Disposal of excrement to avoid or reduce its harmful effect is therefore important. The methods of disposing of excrement in Coccidae are described. These insects have an anal apparatus for propulsion of excrement away from the body. The musculature of the rectum is not involved in this act. Attendance by ants modifies excretory behaviour in Coccidae, much as it does in Aphididae.
The taxonomic status of the Japanese citrus flower-bud midge, Contarinia okadai (Miyoshi) comb. n., and of the citrus blossom midge, C. citri Barnes (Diptera: Cecidomyiidae)
Authors: Harris K. M. , Yukawa J.
Published: July 2009

A gall midge that attacks citrus flower buds in south-western Japan is redescribed under the name Contarinia okadai (Miyoshi) comb. n. and is compared with C. citri Barnes, which was originally described from cultivated citrus in Mauritius. C. okadai, for which a neotype is designated, is distinguished from C. citri by morphological characters of the adult males and females and of the larvae. The known host-plants, biology and distribution of C. okadai are recorded, and new Japanese and English names for the species are proposed. The status of records of C. citri from Sicily, Cyprus, Israel, India, China and Hong Kong is discussed, and the need for further taxonomic research is stressed.
The identity of Lecanium krugeri Zehntner (Hemiptera: Coccidae) and its distribution on sugar-cane in southern Asia
Authors: Williams D. J.
Published: July 2009

The identity of Lecanium krugeri Zhnt. is established, and the species is redescribed in a new genus Saccharolecanium. Originally known from Java, the species is now recorded from India and West Malaysia on sugar-cane.
The dispersion of active Glossina morsitans morsitans Westwood and G. pallidipes Austen (Diptera: Glossinidae) near a large tree and an assessment of the capturing method used
Authors: Phelps R. J. , Chapman N. G.
Published: July 2009

Large electrocuting nets were used at different seasons near a big tree in Zimbabwe to capture tsetse flies at different heights, distances from the bole and times of day. Some differences were found between species and sexes, but most flies were caught within 3·3 m of the ground and in the late afternoon. In the cool and wet seasons, Glossina pallidipes Aust. was less confined to lower levels than was G. morsitans morsitans Westw. Flies, especially fed males of G. pallidipes near the bole of the tree, were recorded in the greatest numbers in the midday period. Diurnal variations occurred in the relative proportions of females of the two species caught at different points. Releasing ox odour through an electrocuting net suspended at different heights confirmed that most flies were flying near the ground, especially in the hot dry season. Comparison of samples from the large electrocuting nets with those caught by other methods operated contemporaneously showed that the large nets gave samples which compared well with those from an electrocuting screen used in conjunction with a ventilated pit. Methods involving fly-capture by people gave very distorted results for all catch parameters examined. No method used gave consistently representative samples of replete flies or of newly emerged flies.
All-female broods in field and laboratory populations of the Egyptian cotton leafworm,Spodoptera littoralis(Boisduval) (Lepidoptera: Noctuidae)
Authors: Brimacombe Linda C.
Published: July 2009

Egg-batches ofSpodoptera littoralis(Boisd.) collected in Crete showed an abnormal sex ratio; 24% yielded predominantly female adults. The field data and data from nine generations of a laboratory strain, which also produced predominantly female offspring, showed that this abnormal condition was transmitted between generations by the females. The mean percentage hatch of egg-batches collected from the field which produced females only was 59·6, and the mean percentage hatch of the eggs of the laboratory strain was 58·8. These results suggest that the production of females only is a result of the mortality of the male embryos. Occasionally, abnormal females from the laboratory strain reverted to producing offspring of both sexes. This recovery from the abnormal condition became more common as successive generations were bred in the laboratory. One female of a normal strain produced all-female offspring and descendants of this female were similarly affected. The females of the unisexual laboratory strain were similar in appearance to normal females but laid significantly smaller egg-batches.
The phenology of Oscinella spp. (Diptera: Chloropidae)
Authors: Vickerman G. P.
Published: July 2009

Counts were made of the numbers of Oscinella adults caught in water traps in plots of grass and oats and in a suction trap in north-eastern England in 1969 and 1970. The numbers of eggs laid by O. frit (L.), O. vastator (Curt.), O. nitidissima (Mg.), O. hortensis Collin and O. maura (Fall.) on their respective host-plants were also counted. In both years, there were two generations of O. nitidissima and O. nigerrima (Macq.) and one of O. maura. In 1969, there were two generations of O. frit and one of O. hortensis and O. vastator. In 1970, there were partial second generations of O. hortensis and O. vastator and a partial third generation of O. frit. O. nigerrima was the first species to appear in the spring, followed by O. frit and O. nitidissima. O. hortensis, O. vastator and O. maura emerged later, and these species dominated the trap catches in July. The proportions of O. frit and O. nitidissima increased in August, and by late September these species again dominated the catch. The proportions of O. vastator and O. hortensis in the suction-trap catches were much lower than in the water-trap catches. Adults of all species were always found in the grassland water traps before they were found in the suction trap. The migratory requirements of other species in the genus, in particular O. maura and O. vastator, may be less than those of O. frit. The oviposition period on particular grass species was relatively long, and thus control of Oscinella spp. on grassland would be difficult.
The influence of temperature and humidity on the life-cycle of Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae)
Authors: Cox P. D. , Crawford L. A. , Gjestrud G. , Bell C. H. , Bowley C. R.
Published: July 2009

The development of a stock of Corcyra cephalonica (Stnt.) from Burma was followed carefully on a diet of wheatfeed, glycerol and yeast at constant temperatures ranging from 15 to 37°C and humidities from 15 to 90% RH. Two other stocks, from Nigeria and Malawi, were also studied under a few conditions. Limits for complete development from egg hatch to adult emergence were about 17 and 35°C at 70% RH. At 15°C, all larvae died early in development, but at 37·5°C a few managed to pupate. Highest survival and most rapid development occurred at 30–32·5°C and 70% RH. Development was completed in the range 15–80% RH, but few adults emerged at 15% RH and none at 90% RH unless a mould-inhibitor was present in the food. No second-generation larvae were obtained from adults reared and kept at 20°C and 70% RH. Egg period was influenced by temperature but not by humidity in the range 20–80%, RH. Eggs hatched at temperatures from 17·5 to 32·5°C. Hatch was adversely affected by low humidity, and very few hatched at 20% RH. Considerable variation in the rate of egg hatch between the three stocks may have been due to differences in the length of time each stock had been reared in the laboratory. Cold tolerance of eggs of the Nigerian stock was low. All eggs died at 10°C after a seven-day exposure, and at 15°C, although a few 0–1-day-old eggs exposed for 14 days hatched, none completed development to the adult stage. Although older eggs were slightly more cold-tolerant than younger ones at 10°C, they were less so at 15°C. Adult males tended to emerge earlier and live longer than unmated females. Adults of the recently collected Malawi stock were heavier and lived longer than those of the Burma stock that had been reared in the laboratory for many generations.
Contribution to the distribution of Glossina (Diptera: Glossinidae) in Mali
Authors: Okiwelu S. N. , Van Wettere P. , Maiga S. , Bouare S. , Crans W.
Published: July 2009

A ground survey to map the distribution of Glossina prior to the initiation of a control programme was undertaken in an area of more than 100 000 km2 in the Sudan and Guinea savanna zones of Mali. The area extends from 11°13′ to 14°15′N. and 5°53′ to 10°24′W. The Challier-Laveissière trap was the main survey tool, but other methods were used when the traps did not catch flies in areas suspected of being suitable for Glossina. The results are compared with existing distribution maps of the area, including one based solely on interpretations of earth satellite photography of the area. Infestation by G. morsitans submorsitans Newst. was continuous west of 8°20′W. and intermittent east of this. Apparent recent advances of G. m. submorsitans and G. palpalis gam-biensis Vanderplank were noted, but G. tachinoides Westw. seemed to have receded. Possible reasons for these differences between species are discussed.
The analysis and standardisation of light-trap catches of Heliothis armiger (Hübner) and H. punctiger Wallengren (Lepidoptera: Noctuidae)
Authors: Morton R. , Tuart L. D. , Wardhaugh K. G.
Published: July 2009

Hourly and nightly catches of Heliothis armiger (Hb.) and H. punctiger Wllgr. at a site adjacent to 2000 ha of commercial cotton in the Namoi Valley of New South Wales, were analysed in relation to various environmental factors and showed that wind speed, temperature, night-length and (H. armiger only) moonlight exerted a significant influence on trap-catch. For H. punctiger and H. armiger respectively, these factors accounted for 80 and 60% of the deviance in hourly catches but only 70 and 40% of the variation in nightly catches. Wind speeds of more than 1·7 m/s suppressed the catch of both species but had a greater effect on H. punctiger than H. armiger. Whereas with both species, the optimum temperature for trapping was about 27°C, temperature had a greater influence on the catch of H. punctiger than of H. armiger. Bright moonlight was estimated to reduce the catch of H. armiger by 49%, but no significant effect was detected for H. punctiger. The analysis revealed a number of occasions for both species in which the hourly distribution of catch and/or the change in catch between successive nights was aberrant. With H. armiger, these inconsistencies appeared to be associated with changes in population due to adult emergence, whereas for H. punctiger the most likely cause seemed to be changes due to movement. The combined effects of wind speed, temperature, night-length and moonlight were used to adjust the nightly catches of each species according to the environmental conditions prevailing on a ‘ standard’ night. This was defined as a typical summer's night with temperatures decreasing from 28·8°C at dusk to 20·6°C at dawn and ideal catching conditions, i.e. no moon and wind speed never exceeding 1·7 m/s. As such, the adjusted catches could be taken as indices of moth abundance. These showed that H. armiger had three discrete periods of abundance, characterised by the presence of large numbers of young moths and spaced at intervals suggesting successive generations. A similar pattern was lacking in H. punctiger, which was abundant only during the first half of the season. Except during periods of emergence (H.armiger), or once when spraying occured during daylight, the aerial application of insecticides to the cotton adjecent to the light-trap resulted in marked reductions in the populations of both species.
Some effects of three species of dung beetles (Coleoptera: Scarabaeidae) in south-western Australia on the survival of the bush fly, Musca vetustissima Walker (Diptera: Muscidae), in dung pads
Authors: Smith T. J. Ridsdill
Published: July 2009

The effectiveness of three species of scarabaeids in reducing the survival of Musca vetustissima Wlk. in cattle dung was compared in laboratory experiments in Australia at 27°C in which the arthropod fauna collected in dung-baited traps in different localities at different times of year was added to one-litre dung pads containing known numbers of M. vetustissima eggs. The dung was collected from each site at the time of the experiment. Onitis alexis Klug collected in October and December at Geraldton, and Onthophagus binodis (Thnb.) collected in January at Bunbury, shredded most of the dung, reducing fly survival to 4% of that in control pads. O. binodis collected in March and October at Bunbury, and O. ferox Har. collected in May and December at Busselton, mostly buried dung, reducing fly survival to 32% of that in controls. Factors other than the numbers of beetles were also important in determining the degree of suppression of the fly.
The role of blood intake in density regulation of populations of Triatoma infestans (Klug) (Hemiptera: Reduviidae)
Authors: Schofield C. J.
Published: July 2009

The growth of populations of Triatoma infestans (Klug) depends on temperature and blood-intake. Experiments are described which demonstrated the density-dependent relationship between population size, blood intake and population growth at different temperatures. The number of bugs feeding and their mean blood intake was lower at high bug densities than at low ones, both with restrained chickens and with unrestrained mice as hosts. When blood intake was restricted, the development times of all nymphal stages were increased, and female fecundity was decreased. Previous work showed also that reduced blood intake led to an increased tendency for adult flight. It is thought that at high bug density the three factors, increased development times, decreased fecundity and increased flight, operate to restore the population to a stable density without promoting an increase in mortality. The mechanism linking population density to nutritional status seemed to depend on host irritability, which interrupted the bugs' feeding. Bugs which passed a certain threshold meal size would not resume feeding if interrupted, even though their blood intake was well below normal. The difference between the minimal threshold meal and a normal meal is thought to provide the nutritional elasticity within which the development processes are regulated. It is suggested that this mechanism is characteristic of K-strategists, whereas r–strategists such as mosquitoes tend to continue attacking, even if interrupted, until they achieve a normal meal.
Control of pink boll worm, Pectinophora gossypiella (Saunders) (Lepidop-tera: Gelechiidae), in Egypt by mating disruption using an aerially applied microencapsulated pheromone formulation
Authors: Critchley B. R. , Campion D. G. , McVeigh L. J. , Hunter-Jones P. , Hall D. R. , Cork A. R. , Nesbitt B. F. , Marrs G. J. , Jutsum A. R. , Hosny M. M. , Nasr El-Sayed A.
Published: July 2009

A large–scale mating disruption trial for the control of Pectinophora gossypiella (Saund.) was carried out in the Fayoum Province of Egypt during the 1981 cotton season. Two areas, each of 50 ha, were sprayed with a microencapsulated formulation of the sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-1, 11-hexadecadienyl acetate) as the sole means of controlling this pest. Five applications of 10 g a.i./ha were made during the season using fixed-wing aircraft. The pheromone treatments were compared with conventional insecticide spray treatments in two other 50-ha areas of cotton. From comparisons of treatments in terms of various plant damage criteria including the percentage of rosetted flowers, percentage boll infestation, gross yield of seed cotton and lint quality, it was concluded that the pheromone treatment was equal in effect to the insecticide sprays.
Light-trap catches of African armyworm moths, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in relation to rain and wind
Authors: Tucker M. R.
Published: July 2009

The association between weather and light-trap catches of Spodoptera exempta (Wlk.) was examined for four traps in East Africa, using whole–night catches and several years' data. Large increases in trap catch were found to be (1) significantly associated with rain at all four traps for the period December–March, but not for later in the season; (2) significantly associated with light wind periods at Muguga for December–May, but not later in the year, and not at Nakuru, due to the very high overall frequency of light winds there; and (3) not significantly associated with windshifts at either Muguga or Nakuru. These results suggest that high densities of flying moths, which may give rise to caterpillar outbreaks early in the year, often occur where the rather infrequent early–season rains fall.
Integration of insect sterility and insecticides for control of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Tanzania. V. The impact of sequential releases of sterilised tsetse flies
Authors: Williamson D. L. , Dame D. A. , Gates D. B. , Cobb P. E. , Bakuli B. , Warner P. V.
Published: July 2009

A field trial of the sterile insect technique was conducted in Tanzania using males of Glossina morsitans morsitans Westw. that were reared, irradiated and packaged at Tanga. The experimental site was a 195–km2 area 110 km to the south. Following two applications of endosulfan as an aerosol at an interval of 28 days, irradiated puparia of G. m. morsitans were released twice weekly at stations distributed throughout the experimental site. Each of the 120 release stations was serviced every 14 days with puparia which produced sterile adults synchronously within 30 min after placement. Over the 15–month experimental period, an average of 81% control of G. m. morsitans was obtained, whereas G. pallidipes Aust., against which no releases were carried out, recovered to prespray levels within five months. The released sterile insects were found to be highly competitive and to survive well in the field. Immigration of indigenous flies from outside the perimeter barrier surrounding the experimental plot provided a continuous influx of fertile flies that provided the nucleus of the 19% residual population. Under operational conditions, the prevention of migration should result in the elimination of an indigenous G. m. morsitans population subjected to the combined stress of population reduction by two applications of endosulfan aerosols and sequential releases of sterile males.
Environmental factors associated with fluctuations in the numbers of natural enemies of a population of citrus red scale, Aonidiella aurantü (Maskell) (Hemiptera: Diaspididae)
Authors: Atkinson P. R.
Published: July 2009

Natural enemies of Aonidiella aurantü (Mask.) were counted in suction-machine samples taken fortnightly over 41 months from an orchard of orange trees in the Swaziland lowlands, a region where biological control of the scale is difficult. Changes in the log population intensity/‘twig’ (Δ log N) of four species were, in each case, calculated over four thermal constants of 5000, 10 000, 15 000 and 20 000 hour– degrees above 12°C (h°>12C). The middle two constants were assumed to approximate to the thermal constants of the generation times of the natural enemies. For each natural enemy, Δ log N measured over each thermal constant was related by regression analysis to climatic and biotic indices to see how the interval over which population change was measured affected the conclusions. The longer the interval, the greater was the percentage of the explained variation in Δ log N, and the greater the number of indices that became significant. However at 20 000 h°>12°C, population change was measured over rather long intervals for short–lived species like Aphytis. At both 10 000 and 15 000 h°>12°C, the number and the identity of the significant indices in the regression tended to be the same. Consequently, conclusions about the factors affecting the natural enemies were based on these regression results. A. africanus Qued–nau, Comperiella bifasciata How. and Rhyzobius lophanthae (Blaisd.) responded directly to changes in their host's numbers, but Habrolepis rouxi Comp. responded inversely and was unlikely to have been effective. Furthermore, it was sensitive to high summer temperatures, as was A. africanus and possibly R. lophanthae. C. bifasciata was not sensitive to high summer temperatures but was adversely affected by the hyperparasitoid Marietta javensis (How.). None of the natural enemies was affected by prevailing saturation deficits.
Electrophoretic study of enzymes from cereal aphid populations. II. Use of electrophoresis for identifying aphidiid parasitoids (Hymenoptera) of Sitobion avenae (F.) (Hemiptera: Aphididae)
Authors: Castañera P. , Loxdale H. D. , Nowak Kathy
Published: July 2009

The effect of parasitism by the aphidiid wasp Aphidius uzbekistanicus (Luzhetski) on the isoenzyme banding patterns of 14 soluble enzymes separated by one–dimensional slab polyacrylamide gel electrophoresis from crude homogenates of its main host, Sitobion avenae (F.), are described. Parasitism was found to be detectable using any 12 of these enzymes. The differences observed between the banding patterns for three enzymes (ester–ase, malate dehydrogenase and malic enzyme) separated from the adults of five primary parasitoid species attacking this aphid (A. picipes (Nees), A. uzbekistanicus, Ephedrus plagiator (Nees) Praon volucre (Hal.) and Toxares deltiger (Hal.)) are also described. Esterase was found to be the best enzyme for taxonomic differentiation of all aphidiid species examined. The use of electrophoresis for assessing percentage wasp parasitism in integrated management studies of cereal aphids is discussed.
Relative frequency of reproductive abnormalities in a natural population of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Zambia
Authors: Madubunyi L. C.
Published: July 2009

Dissection of 2337 female Glossina morsitans morsitans Westw., collected over an 11-month period (118–420 per month) from a game reserve in Zambia, revealed that abortion is a regular feature of tsetse reproductive biology and apparently the most frequent reproductive abnormality in the tsetse population. It occurred among ifies in all ovarian cycles from 1 to 7+4n (minimum age 10–80 days) and apparently involved all pregnancy stages. Neither follicular degeneration nor egg retention was encountered, suggesting that these particular reproductive abnormalities are infrequent in nature.
The relative attractiveness of cattle, sheep and goats to Glossina morsitans morsitans Westwood and G. pallidipes Austen (Diptera: Glossinidae) in the Zambesi Valley of Rhodesia
Authors: Pilson R. D. , Boyt W. P. , MacKenzie P. K. I.
Published: July 2009

A series of investigations was conducted to evaluate the comparative attractiveness of cattle, sheep and goats to Glossina morsitans morsitans Westw. and G. pallidipes Aust. in the Zambesi Valley, Rhodesia. It was shown that cattle are subjected to in excess of three times the challenge by male G. m. morsitans than either sheep or goats. Due to the repellent effect of man's presence on the attraction and feeding of female G. m. morsitansand both male and female G. pallidipes on the bait animals, no rational relationship could be postulated for them. Possible factors accounting for the difference of attractiveness between the three bait species are discussed.
The development rate of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) on winter wheat
Authors: Cannon R. J. C.
Published: July 2009

Intensive monitoring of uncaged summer populations of Metopolophium dirhodum (Wlk.) (alienicolae) on winter wheat in southern England was carried out, mainly in 1979. Estimates for rates of development and reproduction are presented for both apterous and alate morphs. Relative nymphal instar lengths were calculated as percentages of the total juvenile period (instars I–IV inclusive), at a given mean temperature. The durations of the first three nymphal instars were uniform, but longer was spent in instars IV-apterous (21%) and IV-alatiform (45%) than in previous ones. Development rates are shown, firstly as cumulative summations of regression lines for individual instars, and secondly as a single regression for the whole period (I to IV inclusive), plotted separately against corresponding mean temperatures. A method of calculating the development threshold was devised that yielded an estimate of about 5°C for both morphs. Average and maximum daily rates of deposition (larviposition) are given for both morphs and, for apterae, results on the effects on this of leaf, date, temperature and aggregation are presented and discussed. Comparisons are made between this field study, and previous ones using M. dirhodum under constant temperature conditions in the laboratory. Development rates appeared to be similar under both constant and fluctuating temperatures, although slower in the field at low temperatures (10 or 11°C). Reproductive rates under the field conditions of this study appeared to be higher (on a daily rate basis) than those of previous studies, both in the laboratory (at constant temperature) and in the field. Reproduction in the field by apterae is considered to be concentrated over a shorter span of adult life than in the laboratory.
The distribution of five species of flies (Diptera: Muscidae) over the bodies of dairy heifers in England
Authors: Hillerton J. E. , Bramley A. J. , Broom D. M.
Published: July 2009

Five species of Muscidae were found to be commonly associated with dairy heifers in three areas in southern England. The biting flies Haematobosca stimulans (Mg.) and Stomoxys calcitrans (L.) were relatively rare and fed from the back, flanks and legs. The horn fly, Haematobia irritans (L.), was present in highest numbers; it rested on the back and fed on the legs, belly and occasionally on the teats. Musca autumnalis Deg. was found mainly on the head and had a restricted season. Hydrotaea irritans (Fall.) had a marked diurnal variation in activity, being most abundant in the morning and evening. It was found on the head but predominantly on the belly and teats. When judged by its site preference on cattle, it is the fly most likely to be involved in the transmission of summer mastitis.