bluuebunny/crossref_metadata_2025 huggingface dataset:
An Improved Light Trap for Insects
Authors: Williams C. B.
Published: July 2009

In Bulletin No. 28 of the Technical and Scientific Service of the Ministry of Agriculture of Egypt I described a new type of light trap for collecting insects which had the advantages that the insects were rapidly killed in good condition for identification, that the light was visible in all directions, and that it could be used with either electricity or acetylene by an untrained worker.
A new Chalcid attacking Bamboo in India (Hymenoptera)
Authors: Waterston J.
Published: July 2009

♀. Black, except as follows: funicle piceous, base of 6th (8th) tergite dark brownish; scape, pedicel and ring-joint, trochanters, femora and tibiae ferruginous; tarsi much paler; pubescence pale brown to nearly golden (on head) and on funicle paler. The head and thorax somewhat dull; abdomen shining, except on the ventral overlap of tergite 4(6) and on tergite 6(8).
Australasian Simuliidae
Authors: Tonnoir A. L.
Published: July 2009

1. In this paper five species of Simulium and 16 species of Austrosimulium are dealt with.

2. The new genus Austrosimulium differs mainly from the former in the number of joints in the antennae, which are ten instead of eleven; it seems to be restricted to the Indo-Australian region.

3. In many cases the species of Austrosimulium cannot be differentiated from each other in the adult stage, although they are perfectly different in their early stages and especially in the pupal stage.

4. Seven species of Austrosimulium occur in New Zealand: A. vexans, Mik, A. ungulatum, sp. n., A. australense, Schin., A. tillyardi, sp. n., A. longicorne, sp. n., A. multicorne, sp. n., A. laticorne, sp. n. Only the first two of these are distinguishable from the others in the adult stage; the remainder can only be differentiated in the pupal stage or the late larval stage.

5. Five out of these seven New Zealand species are known in their early stages.

6. In Australia (including Tasmania) five species of Simulium and nine of Austrosimulium are known to the writer, i.e.: S. aurantiacum, sp. n., S. fergusoni, sp. n., S. ornatipes, Skuse, S. umbratorum, sp. n., S. terebrans, sp. n., A. crassipes, sp. n., A. cornutum, sp. n., A. tasmaniense, sp. n., A. victoriae, Roub., A. furiosum, Skuse, A. bancrofti, Taylor, A. torrentium, sp. n., A. simile, sp. n., A. weindorferi, sp. n.

The two species A. victoriae, Roub., and A. furiosum, Skuse, have not been identified with certainty, so that further investigation may show that one or two of the new species are synonymous with them.

7. The early stages of one species of Simulium and five of Austrosimulium from Australia are here described.
New Ceratopogoninae from Nyasaland (Dipt.)
Authors: Ingram A. , Macfie J. W. S.
Published: July 2009

Length of body (one male), 2·3 mm.; length of wing, 1·6mm.; greatest breadth of wing, 0·5 to 0·6 mm. A large, dark brown species resembling C. nigripennis, C.I. & M.
Descriptions of two new Species of the Genus Metadrepana (Drepanidae, Lep.)
Authors: Tams W. H. T.
Published: July 2009

Some time ago Mr. T. J. Anderson, Government Entomologist, Kenya Colony, sent to the Imperial Bureau of Entomology several specimens of a Drepanid moth, the larvae of which were defoliating coffee during 1922. The moth, which is described below, proved to be a new one, and I have described at the same time another species from Northern Nigeria, and have given figures of the male genitalia of both species, and of the wing venation (fig. 1) and male genitalia (fig. 2) of the genotype, Metadrepana glauca, Hmpsn.
A new Processionary Moth (Notodontidae) injurious to Pine Trees in Cyprus
Authors: Tams W. H. T.
Published: July 2009

The interesting moth described below was bred from larvae which were causing serious damage to pine trees in Cyprus, by the Entomologist to the Department of Agriculture in Cyprus, Mr. D. S. Wilkinson, who has presented to the British Museum (Natural History), through the Imperial Bureau of Entomology, the two males which he bred.
New Curculionidae attacking Trees in India
Authors: Marshall Guy A. K.
Published: July 2009

♂♀. Integument red-brown, clothed with dense scaling, which may be either nearly uniform grey, or nearly uniform sandy, or again either of these more or less heavily mottled with dark brown; the pronotum with three very faint darker stripes.
A new Armigeres (Diptera, Culicidae) from Ceram (Moluccas)
Authors: Brug S. L.
Published: July 2009

Male and female. Head mainly clothed with black flat scales, with a narrow white border to the eyes broadening laterally, sometimes a central white patch; some upright forked black scales behind. Proboscis black, as long as the front femora in the female, a little shorter in the male. Palpi black; exceeding the proboscis by the length of the apical segment in the male, not quite a quarter as long as the proboscis in the female. Antennae dark brown, pale-banded in the male; the border of the cup of the torus thickly clothed with small flat white scales, especially on the inner side.
Descriptions of two Species of Coccidae feeding on Roots of Coffee
Authors: Laing F.
Published: July 2009

Belonging to the Ortheziinae. Antennae four-segmented, situated on low tubercles; eyes well developed and situated close to but not fused with the base of antenna. Tibia and tarsus distinct, tibia exceedingly short compared with tarsus. Larva with antennal and limb characters of adult. Genotype O. reynei, sp. n.
On some Eulophid Parasites (Hym., Chalcidoidea) of the Oil Palm HĨspid Beetle
Authors: Waterston James
Published: July 2009

Oil palms in West Africa are periodically subject to somewhat serious attacks by Coelaenomenodera elaeidis, Maulik, a beetle of the family HIspidae, which mines the leaves. From the early stages of this beetle Mr. G. S. Cotterell, Assistant Entomologist, Gold Coast, has bred several Chalcidoid parasites, which were forwarded to the Imperial Bureau of Entomology and form the subject of the present paper.
The Distributions of Coccinellid Egg Batches and Larvae in Relation to Numbers ofAphis fabaeScop. onVicia faba.
Authors: Banks C. J.
Published: July 2009

Further analysis of results obtained from a study of populations of Coccinellids on three plots ofVicia fabainfested withAphis fabaeScop, at Rothamsted during 1952 are presented. The distributions of coccinellid egg batches and older larvae (mostly 3rd and 4th instars) on bean stems of five arbitrary classes of aphid infestation, emphasise the differences in the manner of increase of the predator and prey populations considered here; at the same time, the results throw light on the oviposition behaviour of the adult Coccinellids.

The degree of correlation between coccinellid egg batches and Aphids on the plots (as indicated by regression analysis) varied inversely with the size of the aphid populations on the plots. On one plot, where Aphids were extremely numerous, this correlation was negligible; on the two other plots, where Aphids were less abundant, the correlation was more marked, being highest at the plot where the aphid numbers were lowest. The degree of correlation between egg batches and Aphids was determined apparently by the rate of increase of aphid numbers. It is pointed out that while these coccinellid populations increased additively (by immigration of ladybirds to the beans), populations ofA. fabaeincreased multiplicatively (by reproduction) and at much higher rates.

During the early stages of the aphid infestations on the bean plots, when aphid-infested stems were comparatively few, there was no statistically significant association between coccinellid eggs and the presence of Aphids on the bean stems; but when all stems had become infested, egg batches tended to occur most frequently on the stems with the most Aphids. From these and other observations it is concluded that the female Coccinellids do not need the stimulus of the presence of Aphids before laying their eggs on beans, and that they concentrate on well-infested bean stems where they tend to stay and feed on the Aphids and probably oviposit on those stems. The distributions of older coccinellid larvae (3rd and 4th instars) indicate that they, too, tend to concentrate on well-infested stems.

The oviposition habits of the female Coccinellids are discussed in relation to the feeding problems of the newly-hatched larvae.
An inexpensive, easily-constructed, Controlled Temperature and Humidity Room for maintaining Insect Colonies
Authors: Backhouse T. C. , O'Gower A. K.
Published: July 2009

The need having arisen for a small, conveniently situated warm room for the maintenance of mosquitos in a constant environment, the cabinet described below was constructed by the authors at a relatively small cost, and set up in a laboratory-class room (35 ft. x 45 ft.). The warm room, being detached and moveable. entailed no structural alterations or installations.
Halticinae of the Sudan
Authors: Pollard D. G.
Published: July 2009

The distribution of the Sudan HALTICINAE is given, together with brief notes on the food-plants and habits where known, and a key to the species.

Some 39 species, within 19 genera, are known to occur. Many are of minor economic importance, but three can be ranked as major pests. These are the two cotton flea-beetles, Podagrica puncticollis Weise and P. pallida (Jacoby), and Phyllotreta cheiranthi Weise on cruciferous vegetables.
A New Genus for Tortrix postvittana (Walker) and certain other Australian and New Zealand Species (Lepidoptera: Tortricidae)
Authors: Bradley J. D.
Published: July 2009

A new genus, Austrotortrix, is erected for Teras postvittana Walker, the Apple Leaf Roller or Light Brown Apple Moth, a common pest of apple and Citrus in the coastal regions of Australia, and in Tasmania and New Zealand.

Two new synonyms of A. postvittana in addition to those already recorded are given.

As there are several species in Australia closely resembling postvittana, making identification difficult, descriptions of the genitalia of postvittana are given as these provide the best means of positive identification.

Apart from the type species, postvittana, ten other species are assigned to the new genus.
A Culture Method for Culicoides nubeculosus (Meigen) (Diptera: Ceratopogonidae) in the Laboratory, with Notes on the Biology
Authors: Megahed M. M.
Published: July 2009

A simple method for culturing Culicoides nubeculosus (Mg.) in the laboratory is described, the medium used for rearing the larvae being a mixture of powdered mud from near a farm byre, dried autolyzed yeast and powdered charcoal, in the proportions 25:3:2. A layer of the mixture 4 mm. deep was spread over the bottom of unglazed earthenware pots, 6 in. diam. x 1 in. high, and just covered with water. After about three weeks in an insect-proof cage in the open, the pots were brought into the laboratory, the temperature of which was maintained at 20°C. except for brief periods in very hot or very cold weather. Each pot was stocked with from 70 to 220 newly hatched larvae, derived from a single batch of eggs laid on moist filter-paper discs in 3 x 1-inch glass mating tubes by adults that had been fed on human blood and provided with raisins. The surface of the medium became covered with a growth of bacteria, algae, fungi, and protozoa, which provided a source of food for the larvae. These made shallow burrows in the substratum from which they partially emerged to feed and in which they pupated. About 45 per cent, of those introduced emerged successfully as adults.

The incubation and pupal periods lasted 3–6 and about 4–7 days, respectively. The time taken for larval development varied greatly between individuals from the same batch of eggs, and also between batches started at different times of year. The complete life-cycle of examples started as larvae in January–September was thus 3–8½ weeks, the period over which emergence occurred amongst a single batch being 1–5 weeks; the corresponding figures for those started as larvae in October were 6–18 and 2 to nearly 12 weeks.

The behaviour in the various stages is briefly described.
Observations on Anopheline Mosquitos of the Akah River, 4th Division, Sarawak
Authors: Colless Donald H.
Published: July 2009

Investigations on the Akah river, in the 4th Division of Sarawak, showed 13 species and one variety of Anopheles to be present. A. l. leucosphyrus Dön., the principal malaria vector, was the only species common in houses.

A. l. leucosphyrus has a strong preference for human blood and feeds throughout the night, with a peak of activity soon after midnight. Both fed and unfed mosquitos rest indoors on the walls but the latter become increasingly scarcer later in the night. Most individuals rest low down (62% below 3 ft., 96% below 5 ft.) but only a negligible percentage remains in the house after daybreak. Observations suggest that many females spend quite long periods resting outside the house before entering and that entry is almost entirely through windows and other openings in the walls; very few enter the space below the house. There is also evidence of two separate stimuli, or levels of activation, one bringing the mosquito to the bait and one initiating the act of feeding.

Wet weather was accompanied by an abrupt increase in catches of A. l. leucosphyrus and dry weather by a decrease—this is thought not to be due to any effect on breeding places. During the wet period, females entered earlier and tended to rest to a greater extent before feeding.
Studies on the Bionomics of the Case-bearing Clothes Moth, Tinea pellionella (L.)
Authors: Cheema P. S.
Published: July 2009

Tinea pellionella (L.), commonly known as the Case-bearing Clothes Moth or Fur Moth, is of world-wide distribution and is of considerable economic importance. It has been recorded on a variety of substances, particularly those of a keratinous nature. In India, it has been found as an important pest of woollen textiles. Its life-history and habits have been systematically investigated at different levels of temperature and humidity.

The incubation period is 4 to 5, 5, 6 to 7 and 6 to 7 days at 21·5, 25, 30 and 32·5°C., respectively. Temperatures higher than 32·5°C. have been found lethal to eggs. Humidity has no effect on the incubation period. Percentage viability of eggs is greater at lower than at higher temperatures.

Both temperature and humidity have been found to influence the larval development and the number of larval instars. Irrespective of temperature, higher humidities favour shorter larval development and the shortest larval period is at 25°C. and 90 per cent. R.H.

Woollen materials impregnated with yeast are more suited for the larval development than those not so treated. Larvae do not exhibit colour preference. Woollen fabrics dyed with Cloth fast orange G 4 per cent, manufactured by “ Ciba ”, however, inhibit the growth of freshly hatched larvae.

The behaviour of the larvae to direct sunlight has been studied. The rôle of (a) diffused light alternated with darkness, (b) darkness, (c) temperature and (d) humidity on the extent of damage caused by the larvae has been investigated. Under the conditions of the experiments, the amount of damage in continuous darkness was significantly greater than in alternating light and darkness, and that at 90 per cent. R.H. significantly greater than at 30 per cent., but there was no significant difference in the amount of damage at 27·5° and 32·5°C., respectively, and 90 per cent. R.H.

The mode of pupation has been described. The pupal period has been studied and found.to occupy 18 ± 0·4, 10·3 ± 0·16 and 10·3 ± 0·33 days at 21·5, 25 and 30°C. and 90 per cent. R.H., respectively. Humidity has no effect on this period.

The effect of temperature and humidity on (a) the preoviposition, oviposition and postoviposition periods and (b) number of eggs laid by a female has been studied. The life-span of the male and female, the relationship between the weight of the female at emergence and fecundity (which was highly significant) on the one hand and length of life (which was not significant) on the other has also been investigated. Sex ratio between females and males has been found to be 2·6:1. Three to four generations in a year have been recorded at 26 ± 8·0°C. and 82 ± 10 per cent. R.H. when the larvae are fed on woollen fabrics impregnated with yeast.
Notes on the Biology of some predacious Mites on Fruit Trees in south-eastern England
Authors: Collyer Elsie
Published: July 2009

A number of predacious mites of the PHYTOSEIINAE (family LAELAPTIDAE), found in south-eastern England, mostly in association with fruit trees, are listed. Certain measurements and other characters that are of value in separating species are given. The species found were: Typhlodromus tiliae Oudm., T. cucumeris Oudm., T. tiliarum Oudm., T. rhenanus (Oudm.), T. finlandicus (Oudm.), T. umbraticus Chant, T. massei Nesbitt, T. vitis Oudm., T. soleiger (Ribaga), Phytoseius macropilis (Banks) and two Amblyseius spp. Of these, T. tiliae, T. finlandicus and P. macropilis are normally abundant on apple trees, but only T. tiliae remains abundant on commercially-grown apple trees. For each species a list of plants on which it has been found is given.

Details of the life-history of laboratory-reared mites are given and these, together with counts of field populations, show that three generations a year is normal.

Predacious phytoseiine mites feed on several species of TETRANYCHIDAE, including Metatetranychus ulmi (Koch) and Tetranychus telarius (L.); when M. ulmi is supplied in adequate numbers, adults of T. tiliae consume 3 mites per day, the nymphs 2 mites per day, on an average. It is thought that they also feed on plant tissue, since individuals survived in the laboratory for a considerable length of time in the absence of phytophagous mites, though eggs were not laid.
A new Genus and Species of Miridae from Areca catechu in South India (Hemiptera Heteroptera)
Authors: Miller N. C. E. , China W. E.
Published: July 2009

The following description is based on material submitted for identification to the Commonwealth Institute of Entomology by the Government Entomologist, Coimbatore, S. India. The specimens were immediately recognisable as a new genus of the well-defined Mirid subfamily Bryocorinae tribe Odoniellini of which only 18 genera are known. Of these no less than 15 genera are represented in the British Museum (Nat. Hist.).
Field Tests with Larvicides against Culicoides impunctatus Goetgh. in Scotland
Authors: Kettle D. S. , Nash Ruth H. , Hopkins Barbara A.
Published: July 2009

Field tests were conducted on Soutra Hill (1,100 ft. above M.S.L.) in the winters of 1953–4 and 1954–5 to find a suitable larvicide for controlling Culicoides impunctatus Goetgh. In one trial, four formulations (wettable powder, water-miscible concentrate, oil solution and dust) of DDT and γ BHC were applied to plots (10 × 10 yd.) at dosages of 3, 12, 50 and 200 mg. p.p′DDT or γ BHC/sq. ft., except for the γ BHC dust which was applied at 3, 6, 12 and 25 mg. γ BHC/sq. ft. In a second trial, the larvicidal properties of aldrin, dieldrin and malathion wettable powders, chlordane water-miscible concentrate and malathion emulsi-fiable liquid were investigated at three or four of the following dosages —3, 6, 12. 25 and 50 mg./sq. ft. The conclusions to be drawn from these trials were:—

1. DDT was superior to γ BHC at all dosages and in all formulations both in immediate and residual effects.

2. For immediate larval control, DDT and γ BHC wettable powders and DDT water-miscible concentrate were effective but γ BHC water-miscible concentrate was relatively ineffective.

3. Although all the DDT preparations were effective as residual larvicides, the wettable powder was the most successful.

4. For immediate larval control a dosage of 200 mg. p, p′DDT or γ BHC is required. The effect produced by 50 mg./sq. ft. is variable.

5. For residual larvicidal action a dosage of 50 mg./sq. ft. is required although 12 mg./sq. ft. may sometimes be effective.

6. Both preparations of malathion reduced the initial larval density by just over half but they had no residual effect.

7. Chlordane and aldrin achieved an immediate larval reduction of one third but whereas chlordane had a greater residual effect, aldrin was ineffective.

8. Dieldrin had very little immediate (20 per cent. control) but considerable residual effect (72 per cent. control).

9. Wettable powders are the most successful larvicidal preparations.

10. DDT and γ BHC wettable powders at 50 mg. p, p′DDT or γ BHC/sq. ft. are superior to chlordane at the same dosage and slightly better than dieldrin at 25 mg./sq. ft.
Catches in the Gambia, West Africa, ofAnopheles gambiaeGiles andA. gambiaevar.melasTheobald in Entrance Traps of a baited portable wooden Hut, with special Reference to the Effect of Wind Direction
Authors: Bertram D. S. , McGregor I. A.
Published: July 2009

A portable wooden hut with two windows, on opposite sides, fitted with traps to catch mosquitos as they entered the hut was tried, with human bait, as a sampling device for mixed populations ofAnopheles gambiaeGiles and A.gambiaevar.melasTheo. in and near Keneba village in the West Kiang district of the Gambia.

In eighteen night catches, between 24th August and 22nd September 1954, 5,901 females of this species and its variety were taken in the traps, five high catches (642 to 1,240 females) being made before 3rd September and thirteen low catches (27 to 306 females) between 6th and 22nd September. Possible causes for the different size of catches in the two periods are discussed with the conclusion that the differences in catch are not simply attributable to erratic functioning of the hut as a trap.

Four night catches of 186, 741, 797 and 1,240 females ofA. gambiaeand its variety are reported in detail. They reveal that mosquitos were taken virtually exclusively in the leeward trap if the wind persisted from one direction. But if the wind was variable, or conditions were calm, they were taken in both traps, entering the traps alternately as the wind shifted in the first instance and, perhaps simultaneously in calm. The results show that the use of only one trap could give misleading information about the numbers of mosquitos available outside the hut.

There is no doubt that, with wind, the mosquitos approached the host in the hut from down-wind. Since much of the catching occurred in darkness it would seem that the mosquitos were attracted by the emanations of the host and that their approach to the hut was not directed by a visual mechanism controlling up-wind flight.

Heavy rain for about seven hours did not prevent flight.

From hourly collections, made from dusk to dawn, a curve of activity forA. gambiaewith its varietymelaswas obtained resembling the biting cycle reported elsewhere by other authors, the greatest activity occurring between midnight and 0600 hr. All the females (except two instances of incomplete fresh blood-meals) were unfed and, in a small sample, ovarian development was stage II or earlier. First entries occurred just before complete darkness in the evening and the last in good light about 30 minutes after sunrise.

No males ofA. gambiaeor var.melaswere taken in the traps.

The numbers, all females, of other species taken were: 1 ofA. funestusGiles, 1 ofA. rufipesvar.ingramiEdw., 59 ofTaeniorhynchus (Mansonioides)spp., 30 ofCulex nebulosusTheo., 19 of C.thalassiusTheo., and 15 of unidentified species. SomeCulicoidesoccurred in the traps and in the hut itself.

The hut, if modified to include a window trap in each of the four walls and a cowl over each window to keep out rain, appears to be a simple and convenient sampling device for certain types of investigations on the biology and behaviour ofA. gambiaeand its varietymelas.
TheCulexMosquitos of the Sudan
Authors: Lewis D. J.
Published: July 2009

Forty five species, two subspecies and one variety ofCulexoccur in the Sudan.

Taxonomic notes are given on a few species, and new localities, mainly for the subgenusCulex, are recorded. The known distribution of all species of this subgenus is shown on maps.

Several aspects of distribution are discussed, and there is a short section on practical importance.
Stability of Grain as a Factor influencing the Oviposition Rate of the Grain Weevil, Calandra granaria (L.) (Col., Curculionidae)
Authors: Coombs C. W.
Published: July 2009

In order to estimate the effect of cracks in floors upon the oviposition rate of Calandra granaria (L.) in an unstocked granary, grain was presented to adults in six ways. The grain was either fixed or loose. Fixation was achieved either by placing grain in cracks in wood or plaster of Paris, or by gumming (in rows or scattered) to glass. The loose grains lay upon glass or plaster of Paris.

A significantly greater number of eggs was laid upon grain that was fixed. The fact that the grains were in rows and partially enclosed when in cracks had no greater effect than fixing with gum. There was no significant departure from a random distribution of eggs in grains when the latter were in cracks.
Duration of the Aquatic Stages of Povilla adusta Navás (Ephemeroptera: Polymitarcidae)
Authors: Corbet Philip S.
Published: July 2009

The duration of the aquatic stages of the mayfly, Povilla adusta Navás, in Lake Victoria, Uganda, has been determined by analysing larval samples from the stomachs of an insectivorous fish, Mormyrus kannume Forsk., and by culturing eggs in vitro. Emergence shows a well-defined lunar rhythm and, since adults live for only about one hour, duration of the aquatic stages must be an integral number of lunar months. Results indicate that a generation is usually completed in four or five months. Approximately the first two weeks of this period are spent in the egg.

The periodicity of reproduction imposes a feeding rhythm on certain species of fish in Lake Victoria. Some biological implications of the need for synchronisation are briefly discussed.
The Genus Musa Linn. and its Role in the Breeding of Aedes (Stegomyia) simpsoni (Theo.) on the Kenya Coast
Authors: Teesdale C.
Published: July 2009

The varieties of the banana plant (Musa) on the Kenya coast, with particular reference to Aëdes simpsoni (Theo.), a species concerned with the transmission of yellow fever in East Africa, are described, and the species of mosquito larvae found in their leaf axils are recorded. A. simpsoni was virtually the only species present.

Details are given of the proportion of leaf axils that contain water and the percentage of these that produce larvae. Breeding was found to take place in all varieties, but to a much lesser extent in that known as Kibungala than in the others. Although there was often more water in the lower and upper axils than in the middle ones they produced less larvae individually than did the latter. Larvae were also found in old axils at the base of the stems in spite of the fact that these sites seldom appear to provide direct access for an ovipositing mosquito. Water was present throughout the year in the upper axils only.

It was found that the water content of axils varied from day to day and from morning to evening during dry periods and that the axils were often apparently dry for days at a time although the larvae were able to survive. It is suggested that the larvae are able to survive in the water film at the base of the axils, but that such unfavourable conditions may account for the retarded growth that has been observed.

The relationship between water content and number of larvae per axil is discussed, and the conclusion is reached that unless all measurements of water content for all varieties are made simultaneously each day, a comparison of average water content becomes impossible, and therefore no connection can be established from the data so far available.
Observations on the Behaviour of Culicine Mosquitos in African Huts
Authors: Phipps John
Published: July 2009

Observations on the behaviour of Culex pipiens fatigans Wied. were made in 24 huts built and occupied by Africans on a sisal estate near Tanga, Tanganyika Territory. Catches were made in four huts each day, an exit trap being fixed on the window from 2 p.m. to 6 p.m. (evening trap) and replaced by another from 6 p.m. to 8 a.m. next day (morning trap), when a spray catch was made of the mosquitos still in the hut. Each hut was used only once a week, for 31 weeks, from December 1952 to July 1953. The females caught were sorted according to the stage of the gonotrophic cycle, as judged by external examination. The stages used were: I, no blood, no visible ovaries; II, stomach full of blood, ovaries small; V, little or no blood, ovaries fully developed; III and IV, intermediate between II and V.

An analysis of variance was performed on the results. Catches of both sexes showed a significant variation with time, which was not, however, correlated with rainfall. Significantly different numbers were taken in the traps and in the huts. Females were significantly most numerous in the hut catch, and males in the morning trap, the former result suggesting that most females spend more than one day in a hut. There were significant differences between the numbers of females in the different stages of the gonotrophic cycle, stages I and II together accounting for 80 per cent, of all females caught. The high proportion of stage I is attributed to delay between emergence and feeding, and of stage II to the taking of more than one meal during the gonotrophic cycle, later meals obscuring the state of ovarian development. There were significant differences between huts as regards the numbers of females caught, but not as regards males, and it is concluded that this is due to variations in the attractiveness of the inhabitants of the huts.

Females in stage I were most numerous in the morning trap, those in stages II–IV were taken only rarely in traps, but there was no significant difference between numbers of stage V caught in huts and in the two window traps. These results arse attributed to restlessness in both hungry and gravid females, and sluggishness in fed ones. All stages except III were significantly more numerous in some weeks than in others and this might be due to variations in either rate of reproduction, or rate of loss of mosquitos from huts. There were significant variations in behaviour in different weeks. For females, this is attributed to changes in the proportions of the stages with time and the dependence of behaviour on stage. For males, there is some evidence of a relation between behaviour and humidity outside the hut. For females, the distribution of stages between different places of capture changes with time, stages II and III being most consistently associated with hut catches, while the most variable behaviour is shown by stage V.

The necessity for behaviour studies on mosquitos in the field is pointed out, especially in relation to field trials of residual insecticides.
Method for Breeding, Handling and Sexing Adults of Drosophila melanogaster Mg. as a Test Insect for Bioassay
Authors: Gerolt P.
Published: July 2009

A method is described by which a continuous supply may be produced, efficiently, of large numbers of adults of Drosophila melanogaster Mg. of known age and sex for microbioassay tests.

Equal numbers of male and female flies were introduced into breeding jars containing a nutrient medium and maintained at 24–25°C. and 60–80 per cent, relative humidity. They were removed ten days later, just before the emergence of their progeny.

It was found that the physical conditions in the culture jars exerted an appreciable influence on several aspects of the breeding of Drosophila. Thus, in trials in which the surface of the nutrient medium was flat and unbroken, with a pad of cotton-wool laid on it to provide suitable sites for pupation, and with or without a layer of cotton-wool beneath it, or in which the medium was broken with irregular lumps, laid on a layer of cotton-wool and arranged with a space, filled with cotton-wool, at the centre, the best results were obtained with the last modification.

Under these conditions, emergence of adults began earlier and reached its peak earlier, a most constant sex-ratio and a higher number of progeny per female, and consequently a higher yield of flies per culture jar, were obtained.

A special device, which takes advantage of the positive phototropism of the flies emerging from a group of culture jars enclosed in a darkened box with an exit funnel leading into a collecting jar, made it possible, by daily replacement of the collecting jar, to remove practically all newly emerged flies within 24 hours, so that the known age of any batch is accurate within the limit of one day.

Male flies have been found to be twice as susceptible as females and give a greater response to differences in dosage of toxicant. For this reason male flies only are to be preferred for use in bioassay experiments.

Using another device, the flies were therefore sexed, and the required number of batches of males collected. This device consists of a glass-covered container through which a gentle continuous stream of CO2/air is passed over the flies, which have already been anaesthetised with CO2. The male flies are taken up individually with a small aspirator and passed direct into test tubes where they are collected in batches.
The Effect of Obstructive Clearing on Glossina palpalis (R.-D.)
Authors: Nash T. A. M. , Steiner J. O.
Published: July 2009

An experiment has been undertaken in Northern Nigeria to ascertain whether the felling of the trees forming the overhead canopy and the deliberate blocking, with trash, of the stream-bed to obstruct the tsetse's flight-line, would result in the eradication of Glossina palpalis (R.-D.).

Obstructive clearing was employed on approximately 3¾ miles of stream. The results suggest that, provided the experimental reaches are adequately isolated, obstructive clearing does lead to the eradication of G. palpalis.

It is noteworthy that if, owing to inadequate isolation, the cleared stream becomes re-infested in the rains, conditions for at least the first two dry seasons are so unfavourable that flies cannot persist.

The immediate effect of obstructive clearing is to increase greatly the hunger of the few surviving flies.

Records suggest that obstructive clearing leads to a considerable reduction in the number of human hosts visiting uninhabited parts of the stream, presumably because of the destruction of forest produce. The duiker (Sylvicapra and Cephalophus) population also becomes greatly reduced, especially in the vicinity of hamlets. The hunger observed in the surviving fly population may therefore be in part due to an actual reduction in the number of hosts, as well as to the altered environment, which prevents free movement, under shade, of the hungry tsetse that is searching for food; instead, the tsetse is forced out into the open, where the climate in the dry season is intolerable, and presumably the unsuccessful fly rapidly succumbs from water-loss.

The effect of obstructive clearing on the vegetation is as follows. Within a few weeks the mound of trash is overgrown with creepers, Mucuna pruriens becoming dominant. In the first year's heavy rains the mound of trash tends to sink down in the stream-bed; on larger streams, spates do some temporary damage to the creeper growth and gaps may appear in the obstruction. The impression gained is that the blockage will persist for many years on small tributaries, but will disintegrate within a few years on larger streams. In very hilly country, with a rapid run off, the obstruction is likely to be displaced. In perennial streams of the type dealt with, the annual fires make only small inroads into the obstruction.

The technique evolved for the obstructive clearing of streams is described. The cost of this method worked out at 390 man days per mile, which is about half the cost of the present methods.

Should large-scale undertakings in the field confirm the efficacy of this new method, the biggest saving will be the elimination of the present necessity to re-slash streams that have been partially cleared. Observations will be continued to ascertain how long it will be before the vegetation again becomes suitable for G. palpalis.
An Investigation into the Effect of Cultural Conditions on Populations of the Vectors of Virus Diseases of Cacao in Ghana with an Evaluation of seasonal Population Trends
Authors: Cornwell P. B.
Published: July 2009

A comparison is made of the populations of mealybugs, ants, predators and parasites on cacao growing in dense secondary bush and under well-cultivated conditions in Ghana, West Africa. The percentage of cacao trees infested (termed the infestation rate), the number of colonies and the populations of the vectors were similar under the two cultural conditions. Populations of ants of the genus Crematogaster and of COCCINELLIDAE were higher in bush areas than in cultivated ones. Populations of ants of the genus Pheidole, though smaller than those of Crematogaster, were greater in areas of well-maintained cacao.

Correlations of infestation rates and populations were compared under the two cultural conditions for mealybugs, ants, predators and parasites. The field data showed an exponential relationship between these factors, which was rendered linear by suitable transformations. The correlation of mealybug populations with infestation rate and with populations of parasites and predators was equally high in both habitats. The correlation of mealybug populations with those of Crematogaster was closer in the bush than in well-maintained cacao, but the implications of this are not fully understood.

There was a higher infestation rate of cacao during the first three months of the year. In contrast with previous work, the present survey has demonstrated significant changes in the vector population during the year, of a five- or six-fold order. These seasonal changes are based on mean mealybug populations per infested tree, and were largely the result of changes in the numbers of colonies; populations showed a decline during the first six months of the year and then rose to a maximum during October–November. The data suggest that these trends may be brought about largely by changes in the abundance of predators and parasites.
A Study of the Blackfly, Simulium ornatum Mg. (Diptera), with particular Reference to its Activity on Grazing Cattle
Authors: Davies L.
Published: July 2009

Samples of aquatic stages, taken from a small lowland stream near Durham, England, showed that the blackfly, Simulium ornatum Mg., emerged in quantity from April to October (7 months) and that oviposition took place between May and October. Oviposition was confined to the period between sunset and dusk.

Flies emerging in the early summer of 1952 were smaller than those emerging in the spring and late summer of that year.

S. ornatum landed on cattle from dawn to dusk, with usually a small peak 2–4 hrs. after dawn, and a large peak between sunset and dusk on warm, sunny days. On cool, cloudy days the number of flies landing showed irregular fluctuations throughout the day.

The number of flies landing on untethered cattle was not markedly dependent on air temperature or saturation deficiency. Winds of over 5 m.p.h. markedly decreased or inhibited landing activity.

On average about 70 per cent, of all blackflies landing spent less than 10 min. on cattle after landing, and this interval sometimes decreased as the total number of flies landing per unit time increased.

Of the flies which landed, some 8 to 25 per cent, were calculated to bite the cow, and the proportion which bit varied significantly from day to day. The number of bites sustained by cattle in the district appeared to cause no ill-effect, apart from the formation of scar tissue in the navel region where most bites were inflicted.
The Cumulative Toxicity of Diniteo-O-cresol applied in Small Doses to Locusts
Authors: MacCuaig R. D. , Sawyer K. F.
Published: July 2009

By the method of attacking flying swarms of locusts with insecticides sprayed directly into the swarm by relays of light aircraft, a proportion of the swarm receives a sub-lethal dose from each sortie. For successful operation it is essential that a substantial contribution to the final mortality should be produced by the accumulation of these sub-lethal doses on individual insects over a period of time. The object of the present experiments was to determine whether such doses applied at intervals are wholly additive in their effects. The poison used was dinitro-o-cresol (Mk. IV DNC solution) and to shorten the experimental procedure, the locusts, Schistocerca gregaria (Forsk.) and Locusta migratoria migratorioides (R. & F.), were dosed by means of a single drop of poison applied to the ventral surface of the abdomen by a micro-drop syringe.

When locusts are given regular daily doses of DNC the doses are not wholly cumulative in their effect. After the second or third day the lethal effect of each dose becomes steadily less, and after the fourth or fifth day it tends to zero, representing a steady state in which the rates of application and loss of insecticidal activity in the survivors are equal.

When the dose is applied in two halves with various time intervals between them, the cumulative effect during the first 24 hours is less in S. gregaria than in L. migratoria. In the latter species it is possible that sensitisation occurs. After three days, the first half-dose has fallen to an estimated 20 per cent, of its initial effectiveness in each species.

These two species are equally susceptible to a single dose expressed as μg. DNC/g. body weight. The females are more resistant than the males to daily doses (relative susceptibility in S. gregaria, 1·54) but probably not to single doses (relative susceptibility, 1·09).

Resistance to a daily dose correlates roughly with resistance to a single dose, the total dose required to produce 50 per cent, mortality in four days being about twice the LD50 for a single dose.

If flight activity does not materially alter the present results, it is evident that the non-cumulative effects of sub-lethal doses could cause a serious loss in the efficiency of an air-spray operation if it were unduly prolonged. Thus a quantity of insecticide sufficient to kill over 99 per cent, of the locusts if applied as a single dose would kill less than 40 per cent, if the application were spread over four days.
Studies on Wheat Bulb Fly (Leptohylemyia coarctata (Fall.)). IV.—The Distribution of Damage in England and Wales in 1953
Authors: Gough H. C.
Published: July 2009

It is estimated that in 1953, as a result of attack by Wheat Bulb Fly, Leptohylemyia coarctata (Fall.), 59,000 acres of wheat were re-drilled and 58,000 acres were patched with spring-sown wheat; another 85,000 acres were affected without any action being taken by the farmer. The cost of new seed and the reduction of yield of spring wheat as compared with winter wheat represent a minimum financial loss of about £1,200,000. With the aid of maps it is shown that the distribution of damage is similar to the distribution of wheat and to the area with less than 30 in., rainfall annually. In districts where over 5 per cent. of the combined crops and grass acreage is in potatoes, there is a tendency for the amount of damage by Wheat Bulb Fly to increase with increasing potato acreage.

It is tentatively suggested on circumstantial evidence that high rainfall on the west side of the country is partly responsible for the absence there of damage by Wheat Bulb Fly. Many of the variations in the distribution of damage on the eastern side of the country could be accounted for by differences in cropping.

In Scotland, the distribution of the fly is also confined to the eastern side. There are a few records of the fly in the Republic of Ireland.
The developmental biology of Telenomus remus Nixon (Hym., Scelionidae)
Authors: Gerling Dan
Published: July 2009

The developmental biology of Telenomus remus Nixon is described from rearings within the eggs of Spodoptera littoralis (Boisd.). It has two larval instars and its developmental duration at 25°C is about ten days. Superparasitism can be easily induced in the laboratory, but only one adult emerges from each host egg.
The biology of Physcus seminotus Silv. and P. subflavus Annecke & Insley (Aphelinidae), parasites of the sugar-cane scale insect Aulacaspis tegalensis (Zhnt.) (Diaspididae)
Authors: Williams J. R.
Published: July 2009

Physcus seminotus Silv. (properly P. sp. nr. seminotus Silv.) and P. subflavus Annecke & Insley (Aphelinidae) are parasites of the sugar-cane scale insect Aulacaspis tegalensis (Zhnt.) (Diaspididae) in East Africa and they have been purposely introduced into Mauritius where A. tegalensis is an important pest. P. seminotus has brachypterous, flightless females and P. subflavus winged females but their biology is essentially similar. The parasites are arrhenotokous and fertilised and unfertilised eggs are deposited in different sites concomitant with development of female and male larvae on different primary hosts. Female larvae develop endoparasitically in A. tegalensis from fertilised eggs deposited in the host's body cavity. Male larvae develop ectoparasitically on immature Hymenoptera in A. tegalensis from unfertilised eggs deposited in the air-filled cavity of the latter's integumentary remnant. The males of the two Physcus spp. are therefore hyperparasitic and they frequently develop on the immature stages, both male and female, of their own kind (autoparasitism). Unfertilised eggs are laid by virgin females and also by mated females, the latter being able to deposit fertilised and unfertilised eggs at will, depending on the egg site encountered. Sexual dimorphism occurs at all stages, including the deposited egg. The preovipositional adult is the preferred stage of A. tegalensis for deposition of fertilised eggs and development of females is most rapid in such hosts. Development in young hosts is arrested until the hosts have grown to virtually their full size. The host of a male is apparently a matter of chance in so far as evelopment will occur on larval and pupal Hymenoptera of various species found in the empty, inflated, brittle integument of parasitised A. tegalensis. Only one individual, whether male or female, develops per host. Oviposition behaviour of mated females is such that superparasitism is largely avoided but it is liable to occur frequently when virgin females oviposit. Adult females will feed on the body fluids of A. tegalensis that are released by insertion of the ovipositor and also on sugary fluids. They live a month or more, ovipositing continually at a gradually decreasing rate, and laying usually 50–100 eggs.
Studies on mealybug (Planococcoides njalensis (Laing)) nutrition: a comparative analysis for the free carbohydrate and nitrogenous compounds in cocoa bark and mealybug honeydew
Authors: Adomako Daniel
Published: July 2009

To obtain dietary information for the laboratory rearing of Planococcoides njalensis (Laing) the bark tissue of cocoa shoots and mealybug honeydew were analysed for their free sugar and amino acid contents. Paper chromatographic analysis showed the bark tissue to contain mainly sucrose, with smaller amounts of glucose, fructose and raffinose. The proportions of sucrose and glucose+fructose in the honeydew were 24–27% and 24–35%, respectively, with the bulk of the 80% ethanol fraction composed of ketose oligosaccharides. The latter compounds may result from the glycosyltransferase action of mealybug invertase which has been partially characterised. Of the free nitrogenous substances, ethanolamine, asparagine, cysteine, lysine and γ-aminobutyric acid, alanine and glutamic acid are preferentially absorbed. It is concluded that these are important mealybug metabolites, which may be supplied with small amounts of sugar in future liquid-diet trials. Their approximate physiological concentrations were estimated by a semi-quantitative method.
An automatic device for the study of tethered flight in insects
Authors: Cullis N. A. , Hargrove J. W.
Published: July 2009

A flight mill is described which permits the automatic measurement of flight duration, speed, periodicity and wing-beat frequency.