bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on the Coccidae of Southern Rhodesia.—II
Authors: Hall W. J.
Published: July 2009

The present paper deals with a further 16 species and varieties of Diaspinae of which 9 are believed to be new to science.

In addition to the acknowledgements already made in Part 1 I desire to express my thanks to the Chief Entomologist of the Department of Agriculture, Pretoria, for his kindness in permitting certain authentic material of South African Coccidae from the collections of his Department to be sent to me, and to Mr. H. K. Munro of the same Department for very kindly looking out the material and forwarding it.
A new Species of Oliarus (Hom., Cixiid.) on Coconut Palms
Authors: Muir F.
Published: July 2009

Oliarus cocosivora, sp. n. (fig. 1).

Male : length, 3·5 mm. ; tegmen, 4 mm.

Length of vertex along lateral margin twice the width at base ; the areolets reaching nearly to middle of vertex ; base angularly emarginate ; a distinct, fine carina down middle of basal half. The median frontal carina forked at base. The fine carinae of mesothorax distinct. The fork of Sc+R slightly more distad than fork of Cu ; the fork of M1, 2 slightly more basad than fork of M3, 4. The genitalia are figured. The anal segment a little longer than wide. The aedeagus armed with large spines.
Two new Moths with Larvae injurious to Coffee in Uganda
Authors: Tams W. H. T.
Published: July 2009

In 1925 (Bull. Ent. Res., xv, p. 289) I described a species of Metadrepana (M. andersoni, Tams) the larvae of which were found defoliating coffee in Kenya Colony in 1922. Figures were given of the male genitalia of three species. The species described below has for some years been known by the name Metadrepana glauca, Hampson, but a year or two ago I discovered, on examining some specimens sent to the Imperial Bureau of Entomology by Mr. H. Hargreaves, that these were not M. glauca, but a new species. Mr. G. L. R. Hancock has recently sent a good series of this new species, which is a very variable one, and I am now able to describe it.
A new Form of Apparatus for photographing Insects
Authors: Marshall John F.
Published: July 2009

In the course of some six years' work, the apparatus here described has been progressively evolved from my original apparatus, which has already been dealt with in this journal (xv, p. 49).
On some Species of Gall-mites (Eriophyidae) found on Corylus avellana, L.
Authors: Massee A. M.
Published: July 2009

The nut gall-mite (Eriophyes avellanae, Nal.) is one of the commonest species of gall-mites that occurs in this country, and it may be found infesting the buds of hazel (Corylus avellana) in almost any hedgerow and copse where this plant grows. The species is found also in America and in Continental Europe. Its life-cycle is very similar to that of the black currant gall-mite, E. ribis (Westw.) Nal.
The Tobacco Capsid (Engytatus volucer, Kirk.) in Rhodesia
Authors: Roberts J. Isgaer
Published: July 2009

1. The Hemipterous fauna of the tobacco plant in Rhodesia during the growing season is confined to a Coreid, Aleurodid, Jassid and a Capsid.

2. A description of the adult and various instars of the Capsid, Engytatus volucer, Kirk., is given.

3. The habits of the insect on tobacco are discussed.

4. Attempted transmission of tobacco mosaic by Hemiptera found on tobacco plants failed.

5. Further experiments with the macerated contents of the thorax of E. volucer have proved it to cause a rolling and puckering of the leafsurface, which is termed “crinkle.”

6. Crinkle is caused by the poisonous nature of the saliva which spreads rapidly through the interior of the leaf. The salivary action does not affect localised centres to any appreciable extent so as to cause a “shot-hole” effect, as observed with other Capsids. The feeding sites are only noticeable when the leaf is held up to the light; rapid translocation currents cause its action to be spread over larger areas.

7. The injury is aggravated in weakened plants grown under adverse conditions, such as the striking of a hard pan in the sub-soil or a stone, or water deficiency.

8. Control can be effectively carried out by thorough cultivation of the soil, and the choosing of suitable sub-soils for root development. Early planting in December is recommended, or even earlier if rains are suitable, so that the plants will be well established before the height of infestation in April.
On the Ethiopian Simuliidae
Authors: de Meillon Botha
Published: July 2009

The object of this paper is to supply a means to the worker in the field for determining the Simuliidae that he may collect, with reasonable accuracy, until such time as he can have them identified by a systematist. A key to the females is given, and Mr. A. W. J. Pomeroy's figures of male genitalia and pupal filaments are reproduced. In this connection the worker is urged not to depend solely on the key to the females, which could no doubt be greatly improved upon when more materialis available, but to make use of the figures of male genitalia and pupal filaments where possible.
Entomological Aspects of Lac Research in India
Authors: Glover P. M.
Published: July 2009

Lac is the resinous encrustation secreted by the scale-insect, Laccifer (Tachardia) lacca, Kerr (Coccidae). Research with a view to the improvement in quality and quantity of this secretion consists therefore in a study of the Coccid itself and the hosts on which it lives, and the relationship between the insect and its hosts. It also entails an investigation of the insect friends and enemies of the Coccid and of its hosts.
Notes on Argas brumpti (Acarina)
Authors: Ruttledge W.
Published: July 2009

Argas brumpti was first described by Neumann, in 1907 from specimens taken by Brumpt in Somaliland (Ogaden), and has since been found to occur also in British East Africa (Kitui) and the Sudan (Erkowit, Gebelein and Nuba Mountains). In the nymphal and adult stages it has a wide range of hosts, including man, but in the larval stage is far less catholic in its tastes. Cunliffe, in 1913, failed to induce the larvae to feed on a domestic fowl; King, in 1915, having similarly failed to rear them on domestic fowls, sparrows, pigeons, doves and bats, found that they would attach themselves readily to the loose skin on the head and neck of the guinea-fowl, Numida meleagris, and engorge. Larvae so fed were reared to maturity. It was believed that the guinea-fowl was possibly the usual host of A. brumpti in the larval stage, but the examination of numbers of guinea-fowl shot in districts in which this tick occurs yielded no confirmatory evidence.
New Braconidae and other Notes
Authors: Wilkinson D. S.
Published: July 2009

Malaya: Teluk Anson, 1 ♀, iii.1923 (G. H. Corbett), 3 ♀♀, 1 ♂, 18.iv.1930; Serdang, 1 ♀, 1 ♂, 17.i.1925 (G. H. Corbett); Kuala Lumpur, 1 ♀, 10.vii.1928 (G. H. Corbett & B. A. R. Gater).

Host. The three more recent series were bred from larvae of the Limacodid moth, Setora nitens, Walk.
Gall Midges (Cecidomyidae) as Enemies of the Tingidae, Psyllidae, Aleyrodidae and Coccidae
Authors: Barnes H. F.
Published: July 2009

This is the second of a series of papers dealing with zoophagous gall midges of the world. The first, “Gall Midges as Enemies of Aphids,” appeared recently (Bull. Ent. Res., xx, 1929, pp. 433–442), while the third dealing with gall midges as enemies of mites is in course of preparation.
Notes on Asiatic Chalcidoidea
Authors: Ferrière Ch.
Published: July 2009

From many parts of the world, but especially from South Asia and Africa, the Imperial Institute of Entomology receives an increasing number of Chalcidoidea, many being important as parasites of noxious insects, but mostly still very little known or even undescribed. The study of all these varied and often difficult species will be the work of many students on parasitic Hymenoptera. For our part we intend to publish a series of notes under the above title, alternatively with notes on African Chalcidoidea, as contributions to a knowledge of the most important or interesting species, the large majority of which have been bred.
Combined spraying Trials against the San José Scale and Peach Leaf-curl in Kashmir
Authors: Kapur A. P.
Published: July 2009

Kashmir valley is the largest deciduous fruit-growing tract in India, and, owing to the increased demand for fruit, many orchards, both large and small, have recently been laid out with technical assistance from the Department of Agriculture. Apple is the first choice of the fruit-growers, but as the trees begin bearing later than many stone-fruits, it is a common practice to plant peaches and nectarines between the rows of the young apple trees; this produces early returns without disturbing and exhausting the soil by ploughing and growing annual crops. With the rapid development of road transport, it is hoped that peaches will find a market outside the valley. The peaches of Kashmir are not so well known as are its apples and pears but with better attention to the trees an increase in production and an improvement in quality should be possible.
An Apparatus for handling small living Insects
Authors: Edney E. B.
Published: July 2009

Investigations undertaken by the writer involved the determining and sexing of a large number of fleas daily, and it became clear that this would be a laborious process unless an apparatus could be designed which would facilitate separation and examination of the insects by making the process as automatic as possible. The technique finally used, though designed primarily for handling fleas, could be adapted for use with other insects of comparable size where examination under magnification is necessary.
The use of DDT as a Mosquito Larvicide on flowing Water
Authors: Ribbands C. R.
Published: July 2009

These experiments are part of the series made by No. 2 Entomological Field Unit, R.A.M.C., on the potentialities of DDT (dichlor-diphenyl-trichlorethane) for military purposes. A report on the use of DDT as a mosquito larvicide on still water has already been published (Ribbands, 1945).
The Use of adhesive Agents in DDT Sprays
Authors: Barnes Sarah
Published: July 2009

A previous investigation by the writer established that the minimum deposit of DDT on both cement and old painted wood necessary to ensure complete mortality of bed-bugs 48 hours after spraying was 0·2 mg. per sq. cm., and that the toxicity of both surfaces diminished slowly over a period of six months. The present work has shown that when DDT is applied with an adhesive agent, the minimum deposit of insecticide necessary on these surfaces to yield a similar kill at the same interval after treatment was only 0·06 mg. per sq. cm. The addition of an adhesive agent to a DDT spray thus effects considerable economy in the use of DDT. Campbell and West (1944), investigating the toxicity to houseflies of coumarine resin and DDT dissolved in white spirit, have reported an increase in the efficiency of DDT when sprayed with an adhesive agent. These authors confined their investigation to a resin only and they suggested that the coumarone resin conferred, in a manner not specified, increased insecticidal activity on the DDT. The present work has shown that relatively small doses of DDT are highly effective in the presence of at least three dissimilar adhesive agents. It is possible, therefore, that instead of increasing the activity of DDT, the agent merely blocks the minute pores of the treated surface, and by minimising absorption of the solution, increases the amount of DDT available to the insect. Alternatively, the adhesive agent may have some affinity for substances on the surface of the bug's tarsi and so assist transfer of DDT from the sprayed surface to the insect.

The residual toxicity of cement treated with DDT and an adhesive agent, like that of a similar surface treated with DDT alone, diminished slowly. The toxicity of painted wood, on the other hand, treated with doses of DDT and adhesive agent ranging from 0·005 to 0·02 mg. per sq. cm., decreased within one month, irrespective of the adhesive agent used. This fall in toxicity is puzzling, particularly in view of the fact that no such decrease occurred when the surface was treated with a heavier deposit of DDT and adhesive agent, namely 0·06 mg. of each per sq. cm. This latter observation seems to preclude a possible interference with the efficiency of DDT by a slow interaction of the paint constituents and the adhesive agent.

The application of these adhesive agents, even in relatively high doses, failed to prevent the removal of DDT from a smooth surface by repeated washing and rubbing; furthermore, an increase in the deposit of adhesive agent does not markedly increase the insecticidal efficiency of a given deposit of DDT.
Factors influencing the Interaction of insecticidal Mists on flying Insects
Authors: David W. A. L. , Bracey P.
Published: July 2009

Experiments are described which illustrate some of the ways in which the results of exposing insects to a spray mist are dependent on either their behaviour or physiological state. Only fine mist dispersals with particles below 10 microns in diameter are considered and in such mists the flight movements of the insects are very largely responsible for the collisions between the insect and the droplets. An increase in flight activity leads to the accumulation of a greater number of spray droplets and consequently a higher kill. Under these conditions insecticides such as pyrethrins which exert a strong irritating action on Aëdes in minimal amounts are superior to DDT which does not have this effect. For practical applications under circumstances where the sprays depend on mist action to produce their effect it is advantageous to mix pyrethrum with the DDT sprays so that the maximum dose of the latter may be accumulated.

Further experiments are concerned with the relative resistance of male and female Aëdes aegypti to insecticides and the change of resistance which takes place on ageing or as a result of a blood meal. It is shown that the male is innately more susceptible to both pyrethrins and DDT and that the resistance of the females is higher after a blood meal. There is also a progressive decrease in resistance with age.
The Hibernation ofMyzus persicae, Sulzer, and some related Species, including a new One (Hemipt. Aphidae)
Authors: Lambers D. Hille Ris
Published: July 2009

Myzodes, Mordv., 1914, typeMyzodes tabaci, Mordv. (═Aphis persicae, Sulzer) is a synonym ofNectarosiphonSchouteden, 1901 (nom. nov. forMacrosiphum, Del Guercio, 1900, nec Passerini, 1860). Following Baker's 1920 Generic Classification,Aphis convolvuli, Kalt. (which clearly isAphis persicae, Sulzer) is the type ofMacrosiphum, Del Guercio, and therefore ofNectarosiphonSchouteden, a subgenus ofMyzus, Pass.
A Machine for Nicotine Fumigation of field Plots
Authors: Wilson A. R.
Published: July 2009

The construction of an inexpensive, simple, hand-drawn fumigator for field plots is described. The general principle employed is the injection of liquid nicotine under pressure into the exhaust system of a two-stroke engine, close to the port. The liquid is vaporised by the heat of the exhaust stream and distributed by it below a drag sheet at the rear of the machine.

The machine is of simple and robust construction, utilising standard plumbing fittings, angle iron, strip iron and second-hand motor-cycle parts and can, therefore, be made where only limited facilities are available.

The machine is self-contained and easily transportable as it can be towed behind a car from one locality to another. It is suitable for use on a wide variety of crops since the track is variable between 43 in. and 67 in. and the clearance between 16 in. and 34 in. With the 18 ft. long sheet used it can fumigate, in good conditions, one acre in about five hours. It is pointed out that the use of a lightweight sheet about 54 ft. long would decrease the time required per acre to about if hours and would enable the machine to be drawn by a tractor if desired; these suggestions have not, however, been tried.

The machine has been in use since 1941 for controlling aphis infestation in connection with work on virus yellows of sugar beet and has given most satisfactory results. Tests showed that a kill of 88–99 per cent, of Aphids was obtained.
Some Observations on the Hunger-cycle of the Tsetse-fliesGlossina swynnertoniandG. pallidipes(Diptera) in the Field
Authors: Vanderplank F. L.
Published: July 2009

The mean hunger-cycles ofG. swynnertoniandG. pallidipeshave been studied in the field by marking tsetses with cut proboscidae, which have been released and subsequently recaptured.

The length of time that hungry flies are able to survive before dying from starvation varies with the season, probably according to the amounts of reserve fats and atmospheric humidity.

The mean hunger-cycle also varies with the season and correlates significantly with the evaporation rate or other measurements of humidity. The variation of temperature experienced in these experiments was not sufficient to have any appreciable effect on the hunger-cycle.

G. pallidipes, a thicket haunting fly and larger thanG. swynnertoni, a thorn bush species, frequently than the latter under moist conditions, but frequently under adverse conditions.

Smaller individuals probably feed more frequently than larger individuals.
Sandfly Control with DDT Residual Spray. Field Experiments in Palestine
Authors: Jacusiel F.
Published: July 2009

Field experiments carried out in 1945 at Rosh Pina in Palestine have proved the great efficiency of DDT residual spray in houses against sandflies.

A high degree of protection against P. papatasii, P. major and P. chinensis was obtained by inside spraying of rooms with DDT in kerosene.

The residual action lasted for 52–58 days during the hot summer months. At the end of this period the effect was still undiminished but the end of the sandfly season made further observations impossible. Judging from observations made elsewhere it may be assumed that the residual effect would have lasted not more than another two weeks.

Dosage of 1 g. per m2 (100 mg. DDT per sq. ft.) was fully effective, and 2 g. per m2 gave no better results. The best method of application is the treatment of all internal surfaces (walls and ceiling). As sandflies tend to congregate in the angle between wall and ceiling, treatment of walls and this angle only gives equally good results.

An attempt to protect a house by spraying “barriers” (vertical surfaces of stone walls etc., within a radius of 50 metres) failed. Sandflies on the outside surfaces disappeared after the DDT treatment but the observations recorded here and those reported by other authors suggest that much larger areas would have to be sprayed in order to make this method effective.

A marked reduction of sandflies in untreated rooms followed the spraying of other Tooms in the same house with DDT. The mechanism of this phenomenon is explained. A general reduction of the sandfly population can be expected when large-scale DDT treatment is carried out in a village or camp area.
Coccids attacking Cacao (Theobroma cacao, L.), in West Africa, with Descriptions of five new Species
Authors: Strickland A. H.
Published: July 2009

Cacao was introduced into West Africa in the latter years of the last century and for a time remained relatively free from pests and diseases. It is, in fact, only recently that two major scourges have developed to a point where they are threatening the future of the cacao industry in the Gold Coast and Nigeria. The first, the cacao Mirids (Sahlbergella singularis, Hagl., andDistantiella theobroma, Dist.) is outside the range of the present paper. The second, and most important, is a virus disease, known as “Swollen Shoot”, which is transmitted from tree to tree by at least three species of mealybugs of the family Pseudococcidae.
The Mosquitoes of Bwamba County, Uganda. VI.—Mosquito breeding in Plant Axils
Authors: Haddow A. J.
Published: July 2009

1. A study of mosquito breeding in plant axils was carried out in Bwamba County, an area with much heavy forest in the extreme west of Uganda. Attention was directed mainly to Aëdes (Stegomyia) simpsoni, a known vector of human yellow fever in Bwamba.

2. The various plants studied are described.

3. The results of preliminary surveys are discussed. These confirmed that, as far as mosquito breeding is concerned, the most important plants in Bwamba are the lowland colocasia (Xanthosoma sagittifolium), the “gonja” variety of cultivated banana and the pineapple (Ananas comosus). It was shown that A. simpsoni is the commonest axil-dwelling larva in the inhabited lowland areas, and that it occurs in widely different types of lowland country. Records are given of the occurrence of larvae of Aëdes (Stegomyia) aegypti in plant axils.

4. A survey of 12 different kinds of plants is described, and it is shown that the larval populations depend to a considerable extent on the amounts of water retained by the axils of the various plants concerned. In Bwamba, medium-sized axils with a capacity of 4 to 8 cc. appear to be the most favourable. Certain plants which yielded large numbers of larvae—such as the wild banana (Musa sp.)—were not found to harbour A. simpsoni. Apparently this is due to the fact that they are confined to forest and mountain areas, where A. simpsoni is scarce or absent.

5. A monthly survey of Xanthosoma axils, carried out over a period of 12 months, showed that A. simpsoni larvae were continually present and that the fluctuations in larval population were dependent on growth and harvesting of the plants rather than on rainfall.

6. Scrapings from dry Xanthosoma axils, taken during a short period of drought, were placed in bowls of water in mosquito-proof cages. Larvae of A. simpsoni and Harpagomyia taeniarostris hatched from this material in 2 to 3 days.

7. Temperature measurements in a Xanthosoma axil showed that the water therein was cooler than the surrounding air and also that the axil temperature was remarkably equable.

8. Systematic collections of pupae from Xanthosoma axils showed that the mosquito output (which cannot be gauged directly from the population of larvae) is high and constant. It is estimated that a plot of 500 plants of this species may, under favourable conditions, produce something like 5,000 A. simpsoni (2,000 females) per month.

The influence of predatory larvae (Eretmapodites spp.) on the populations of other species is thought to be considerable.

9. The fauna of plant axils, apart from mosquito larvae, is described briefly.
Effect of Defoliation on Reproduction of Cordia macrostachya
Authors: Callan E. McC.
Published: July 2009

The importance of finding the effect of defoliation on the reproductive capacity of Cordia macrostachya is explained in view of the proposed introduction of two species of leaf-eating beetles from Trinidad into Mauritius for the control of this weed.

An account is given of experiments in which the production of inflorescences and fruits was compared in defoliated and control plants.

The results show that defoliation has a significant effect in reducing the reproductive capacity of the plant.
A Method of assessing the acaricidal Properties of DDT and “Gammexane” Preparations in Field Trials
Authors: Wilson S. G.
Published: July 2009

DDT and “Gammexane” have many advantages over arsenic as acaricidal agents.

The sites of attachment of the common tick species on bovines are recorded and the killing properties of various dilutions of DDT and “Gammexane” are assessed by observations on R. appendiculatus attached on the ears and A. variegatum attached on the udder and flanks of cattle.

The preparations were usually applied as sprays by means of a flit-gun, an Aerograph spray gun, and Kent sprayer or “Solo” hand pump. A “swirling-jet” nozzle was found most suitable. A possible combined spraying-dipping method using a shallow bath is also described.

In preliminary experiments, a spray containing 2·5 per cent. DDT and a preparation containing 1:10 of the “Gammexane” dispersible powder P.530 killed all ticks attached at time of spraying but the residual effects were lost about the 4th day after spraying. Field experiments gave similar results, but 1:20 of the P.530 powder (0·325 per cent. active gamma) proved equal in killing value to the 1:10 preparation.

The addition of coumarone resin did not increase the residual effects of a 2·5 per cent. DDT emulsified solution.
Successful Methods of trapping Trombicula (Acarina) with Notes on rearing T. deliensis, Walch
Authors: Cockings K. L.
Published: July 2009

The parasitic larvae of a number of Trombiculid mites are of economic importance as they include the vectors of scrub typhus, and scrub-itch mites of considerable nuisance value. Methods of trapping these mites and various field and laboratory observations on them are described. The methods were evolved and observations made during the course of work, sponsored by the Medical Research Council, in Imphal, Assam and Compton, Berkshire.

Live unfed larvae in the field may be concentrated and trapped by use of a low cover with a central light-admitting aperture and collecting apparatus. This method proved very efficient in trapping harvest mites (Trombicula autumnalis) in England. The rise in temperature within the trap can be made advantageous.

Guineapigs were chosen as bait animals for the collection of T. autumnalis at Compton, most of the larvae attaching near the anus and genitalia. The larvae fed for between 30 and 60 hours.

Engorged larvae may easily be collected as they leave their host (or dead animals and débris) by the funicular laboratory light-trap described.

Observations are made on the collection of adult mites, and to a lesser extent nymphs, from soil flotation in water. The vertical migration of adults in relation to soil moisture and temperature is discussed.

Observations on the appearance of larvae of T. autumnalis on a chalk-down at Compton showed a sharp seasonal peak in September, 1946, and some evidence is adduced that this was related to a peak in oviposition.

Observations are made on attempts to rear T. deliensis, the scrub typhus vector in Assam, and notes are added on the behaviour of larval and nymphal mites.
The common House-fly,Musca domestica, L., and its Behaviour to Temperature and Humidity
Authors: Dakshinamurty Sonti
Published: July 2009

The study of the common house-fly,Musca domestica, L., has not received the attention it merits by medical entomologists. Although the correlation betweenfly-borne diseasesandclimatic factorshas interested several workers, this correlation has not been satisfactorily explained. An investigation of the influence ofclimatic factorson house-flies was therefore undertaken.

House-flies can be reared in the laboratory by a proper choice of the breeding medium and suitable technique. Manures, kitchen refuse and synthetic media may be used but the last mentioned is recommended for the production of a supply of standard insects.

M. domesticachooses the lower humidity on each of the humidity gradients, 20–40, 40–60, 60–80 and 80–100 per cent., at a constant temperature of 25°C. The choice is significant for both sexes, and for dry and wet flies, except for dry flies at the range 60–80 per cent.

The house-fly chooses 30°C. in temperature gradients of 20–30°C. and 30–40°C. at constant humidity, expressed either in the R.H. or the S.D. scale. It chooses 30°C. with dry air if possible, but with moist air if it must. In a gradient of 33–27°C. where dry air is associated with 33°C. in the S.D. scale in the one case, and 27°C. in the R.H. in the other, it chooses 33°C. or 27°C. according as it coincides with dry air. Dry air as represented by low R.H. or high S.D. did not make any difference to its choice, consequently it is not possible to decide whether house-flies choose by the R.H. scale or the S.D. scale. The activity ofM. domesticato different combinations of temperature and humidity shows maximum activity with high temperature and low humidity, minimum with high temperature and high humidity; while in the case of low temperature combinations with either high or low humidity, activity lies intermediate in degree. High and low temperatures and high and low humidity within themselves also show significant results by the χ2test.

The experimental results are explained on physiological grounds and the results obtained in these experiments are compared with those of other workers on similar problems on a variety of insects.

The general experience with regard to house-flies in the field is explained in the light of these laboratory findings.

For a correct analysis of the behaviour of the house-fly in nature, biological stimuli such as feeding, breeding and resting habits must be considered quantitatively in relation to environmental factors such as temperature, humidity, rainfall and light. The present work forms part of such a study.
The Penetration of the Insect Egg-shells. I.—Penetration of the Chorion ofRhodnius prolixus, Stål
Authors: Beament J. W. L.
Published: July 2009

The unspecialised portion of the shell and the cap ofRhodniuseggs are impermeable to almost all hydrophilic and lipophilic liquids. If water and very small ions pass through the chorion they must traverse a wax layer on the inside of the shell. Certain corrosive materials,e.g., glacial formic acid, may pass through the shell slowly.

These conclusions, based on experiments with pieces of shell, have been confirmed in ovicidal experiments. A range of materials with widely differing properties enter the embryo only through the micropyles, of which there are approximately fifteen in the rim of each shell. At least one micropyle must be traversed to kill an egg but many eggs were killed when only one had been penetrated.

A cement, applied by the female at oviposition, may occlude the outer orifice of a micropyle. The properties of the cement are described; it appears to be a tanned protein. Cement deposits are much more copious on the eggs laid by younger females. Such eggs are more resistant to ovicides because penetration is delayed. This increased resistance is more pronounced when oleophilic liquids are used owing to the rapidity with which they kill eggs from older females. The random distribution of cement is one cause of the variability of replicates in ovicidal tests.

A detailed investigation has been made of factors governing liquids traversing the micropyles. Hydrophilic liquids invade the outer lipophilic part of the micropyle slowly; the displacement of air is the most important factor and small changes in the wetting power of the liquid make little difference to the rate of entry.

Aqueous liquids aie absorbed into the protein lining of the inner portion of the micropyle. They reach the wax layer on the inside of the shell by migrating into and through the inner protein layer. The area which is invaded increases linearly with time. Mortality, therefore, increases as the square of the time of immersion, but it is proportional to the increase in concentration of a solute if the period of immersion is constant.

Oleophilic liquids wet the micropyle actively. They may by-pass air and flow rapidly to the wax at the inner end of the tube. Wax solvents kill very quickly and are much more toxic than other lipophiles.

Water in the micropyle and shell may affect the entrance of either type of liquid. In general it increases the toxicity of aqueous solutions and retards the entry of oils.

Wax-emulsifying materials added to aqueous solutions do not produce great increases in toxicity. They are “filtered out” at the protein lining of the micropyle and do not reach the wax layer for a considerable period of time.
Stimuli involved in the Attraction of Aëdes aegypti, L., to Man
Authors: Parker Alec H.
Published: July 2009

The reactions of Aëdes aegypti females to certain stimuli normally associated with the human surface body have been investigated. The apparatus used was such that the insects were unable to touch the source of stimulation. Attraction to the latter was indicated by the congregation of females in its vicinity.

The following stimuli proved attractive: the intact palm of the hand; collected sweat at room temperature; moisture at room temperature; moisture at body-surface temperature. A warm surface at body-surface temperature produced no apparent effect, either of attraction or of repulsion.

The four types of stimulus found to be attractive also had marked activating effects. The magnitude of these effects was much greater for the hand and warm moisture, than for cold sweat and cold moisture.

Due allowance for the complication introduced by these differences in activation having been made, cold sweat appeared to be slightly, but significantly, more attractive than cold moisture. A reaction to olfactory stimuli is presumed to have been responsible for this. Such stimuli, however, are not considered to have been of much importance in comparison with warmth and moisture; moisture at body-surface temperature had very nearly, and possibly the same, attractive effect as the intact hand.

The results are compared with those of other recent investigations, and the need for caution in applying them where conditions differ from those under which they were obtained is emphasised.
The Leucoptera Leaf Miners of Coffee on Kilimanjaro. I.—Leucoptera coffeella, Guér
Authors: Notley F. B.
Published: July 2009

Two leaf miners of coffee, Leucoptera coffeella and L. caffeina are present in the Kilimanjaro and Usambara districts of Tanganyika. The life-histories of L. coffeella and its parasites and a study made during 1937–40 of the populations of the host and its parasites in the Kilimanjaro area in both unshaded and shaded coffee are described. Some observations are made on the “dominant stage” of the host.
Notes on Pseudococcus comstocki (Kuw.) and some allied Species (Homoptera: Coccoidea), with Descriptions of three new Species
Authors: Borkhsenius N. S.
Published: July 2009

The determination of mealybugs closely related to Pseudococcus comstocki (Kuw.) has presented considerable difficulty in the past. Green (1921, p. 189) and Hough (1925, p. 52 and 1925a, p. 13) have given details of the distinguishing features for P. comstocki (Kuw.) and P. maritimus (Ehrh.) but the grounds given for the separation of the former from other closely related species are not fully satisfactory. The representatives of this group of mealybugs are becoming more and more widely spread throughout the world and of greater economic importance yearly. A correct designation of these insects is, therefore, of particular importance not only from the point of view of quarantine legislation but also of control measures. Research work on the morphological characteristics of species closely related to Pseudococcus comstocki (Kuw.) has been carried out on very large quantities of material from different parts of the world.
The Penetration of Insect Egg-shells
Authors: Beament J. W. L.
Published: July 2009

During development, membranes are added to the inner surface of the chorion in eggs ofRhodnius prolixus. The chemistry and permeability of the membranes have been investigated.

A true fertilisation membrane is produced immediately before oviposition when the egg is fertilised. It is attached to the inner surface of the primary wax layer, recessed into the micropylar region and covers the whole inner surface of the shell.

The membrane is very thin when first formed. It is colourless, comparatively resistant to solvents and apparently composed of “vulcanised” protein. It is semi-permeable to salt solutions but made very permeable to small molecules when immersed in absolute alcohols.

In the following five days of incubation, further material is added to the fertilisation membrane. Over the main part of the shell and cap, this does not cause a great increase in the thickness of the, membrane. The added material is probably proteinaceous, with tanning- and vulcanising substances and it is mostly a product of the serosa.

Opposite the inner openings of the micropyles, material is accumulated at a much greater rate and by six days incubation the membrane may be fifteen microns thick. The inner surface of the egg-shell thus becomes a uniformly ellipsoidal body. The thickened material has been called the epembryonic ring.

At about the, sixth day of incubation, shortly before blastokinesis, the membrane is partially impregnated with a high-melting-point wax. This raises the “transition point” in the egg's water-loss/temperature curve from 42·5°C. to 68°C. Evidence is against this material being arranged as a second wax layer on the inner surface of the membrane.

No further changes were detected until the thirteenth day when the innermost part of the membranes are broken down by the embryo. On the day before eclosion the embryo is surrounded by a liquid containing emulsified wax and proteinaceous material. The properties of the membranes return towards those of the one-day-old egg but do not attain them ; the egg hatches on the 16th day.

The changes in the membranes produce considerable changes in the apparent toxicity of ovicidal liquids; ovicidal experiments are recorded and explained. In general, the egg becomes more resistant to lipophiles over the first six days and less resistant afterwards, due to the wax impregnation. The resistance to hydrophiles increases during development due to the epembryonic layer and secondary wax, but decreases when the membranes are broken down just before eclosion.
Acrodendrophilic Mosquitos of the Langata Forest, Kenya
Authors: Garnham P. C. C.
Published: July 2009

Langata Forest is a small, detached forest, 11 square miles in area, of the African plateau type, lying 5 miles west of Nairobi at an altitude of 6,000 ft. The forest is mostly secondary and although of evergreen character, much foliage is lost during the long dry seasons. The indigenous trees include olives (Olea chrysophylla), crotons (Croton megalocarpon), muhugu (Brachylaena hutchinsonii) and cape chestnut (Calodendron capense).
On the Indian Species of Rodolia Mulsant (Coleoptera—Coccinellidae)
Authors: Kapur A. P.
Published: July 2009

Species of Rodolia Mulsant (1850) are important as predators of mealybugs, some of which are notorious for their injury to plants. Rodolia cardinalis Mulsant is a classical example of a species that has been successfully introduced into several countries against the cottony-cushion scale, Icerya purchasi Maskell. A campaign against the latter, in South India, has be.en in progress for some time, and a number of local Coccinellid predators, collected by the staff responsible for the work, were sent for identification to the Commonwealth Institute of Entomology. The present study is based mainly on this material, and also on that in the British Museum (Natural History). All the known Indian species are redescribed and three new ones added to the list.
Control of Empoasca lybica, de Berg., On Cotton in the Anglo-Egyptian Sudan
Authors: Cowland J. W. , Edwards C. J.
Published: July 2009

A short account of the life-cycle and symptoms of damage of the cotton Jassid, Empoasca lybica, de Berg., is given. In the initial cage experiments it is shown that DDT emulsion was superior to the copper compounds used. Experiments on the residual toxicity of DDT and “Gammexane” sprays are described. Tests with DDT emulsion showed that very young cotton is injured by emulsion containing as little as 0·025 per cent. DDT, but that emulsions containing up to 0·5 per cent. DDT can be used with safety on plants which are two months old. A coarse DDT suspension caused severe leaf distortion, but a fine suspension used later was quite safe at the concentration used.
The Parasites and Predators Of Potato Aphids
Authors: Dunn J. A.
Published: July 2009

The parasites and predators found attacking the Aphids,Myzus persicae, Macrosiphum solanifoliiandAulacorthum solani, during field survey work of potato Aphids in the Northern Agricultural Advisory Province during 1944 and 1945, are treated individually, receiving the proportionate attention which their occurrence merits.

Aphidius avenaewas the most important primary parasite, and in potato seed growing areas, the only one; whileAsaphes vulgarisin particular, augmented byLygocerus testaceimanuscomposed the majority of hyperparasites. The effect and relative importance of both types of parasite upon the Aphid populations of the survey are discussed with their percentage figures.

Predacious Syrphids includedPlatychirus manicatusandP. immarginatuswhose life-histories were previously unknown; feeding records are also given for these two, and the former species accompanied invariably byP. scufatusoccurred regularly on potatoes. More unusually, but often more effectively,Syrphus balteatusappeared. Other species were found.
Studies on West African Forest Mosquitos.—Part I. The seasonal Distribution, biting Cycle and vertical Distribution of four of the principal Species
Authors: Mattingly P. F.
Published: July 2009

The present paper is the first of two dealing with the seasonal distribution, hourly variation in biting activity, and vertical distribution of certain Southern Nigerian mosquitos. The technique employed in the studies under discussion resembled that used by Haddow (1947) in Uganda. Human bait was used in both cases and the agreement between the results obtained in the two localities is felt to be such as fully to justify the employment of such methods. Over fifty species of mosquitos were taken in all and fourteen of these proved to be sufficiently abundant to yield significant figures. Four of these are discussed and the remainder will be dealt with in the second paper.

The most remarkable feature of the seasonal distribution was the very restricted period during which Anopheles gambiae was present in any abundance. This species occurred in large numbers only during the heavy rains of June and July and, to a less extent, in association with the small rains of September–October. During the dry season it almost disappeared. Aëedes africanus showed a similar distribution to that of gambiae but Taeniorhynchus africanus and Anopheles hargreavesi were most numerous during the dry season. It is suggested that in the area under consideration the latter species may well be a more important malaria vector than gambiae owing to its greater abundance and more uniform seasonal distribution.
Observations on the Control of Kenya Coast Glossina
Authors: Moggridge J. Y.
Published: July 2009

A small reclamation experiment staged in the coral rag thicket under unfavourable conditions proved successful in eradicating Glossina austeni and G. brevipalpis and in virtually eradicating G. pallidipes. Applied with adequate protective clearings, it is thought that the method may prove entirely successful in eradicating G. pallidipes as well as G. austeni and G. brevipalpis.

Under both dry and wet season conditions traps proved quite ineffective.
A simple Method for the Estimation of Contact Insecticides
Authors: Krijgsman B. J. , Berger Nelly E.
Published: July 2009

The great increase, in recent years, in the number of contact insecticides has created a demand for methods whereby the content of active substance in samples of these insecticides may be estimated quantitatively in a simple manner. Such methods are important, because on the one hand the producer wishes to know if his product meets the necessary requirements and on the other hand the official services concerned with the control of insect pests must be able to test the fundamental value of commercial preparations. Moreover quantitative methods for the estimation of contact insecticides are useful for scientific research in this field.
The Duration of the Aquatic Stages of Anopheles minimus, Theo., determined by a new Method
Authors: Ribbands C. R.
Published: July 2009

A new method of determining the duration of the aquatic stages of Anophelines in nature is described. Repeated daily dippings of a stretch of stream were made, and the numbers of pupae and of larvae of each instar were recorded. The duration of the aquatic stages was then determined by analysis of the sequences of peaks in these numbers.

The duration of larval life of A. minimus, when living in a stream at an average daily range of water temperature between 26·5°C. and 30·6°C, was seven days.

The full life cycle of A. minimus, under monsoon conditions in Assam, probably occupied 14 days—egg 2 days, larva 7 days, pupa 2 days, adult to first egg-laying 3 days.
On the Introduction of Scolia ruficornis, F., into western Samoa for the Control of Oryctes rhinoceros, L.
Authors: Simmonds H. W.
Published: July 2009

Oryctes rhinoceros, L., the Asiatic Rhinoceros beetle, was accidentally introduced into Western Samoa, apparently with rubber plants from Ceylon, sometime prior to September 1910. The results were disastrous to the coconut industry, and caused grave anxiety to coconut planters in the adjoining groups.
The Breeding of the Red Locust in Captivity
Authors: Albrecht F. O.
Published: July 2009

Considerable difficulties have been experienced in the past in keeping adults of the Red Locust,Nomadacris septemfasciata(Serv.), alive in cages for any length of time. No satisfactory explanation as to why they die in captivity has so far been given (Hamilton, 1936).
Some Notes on Anoplonyx destructor Benson
Authors: Crooke Myles
Published: July 2009

A new member of the larch-feeding genus Anoplonyx has recently been described in Britain. The species, A. destructor Benson, has been common in British larch woods for some years without, however, causing any very serious amount of damage to the tree crops. Notes on the biology of the species, including larval descriptions, are given and the present forest status of the species is reviewed. Apparently unsuccessful attempts to achieve biological control by the release of Dahlbominus fuscipennis (Zett.) are recorded.
Lead Cable severely damaged by Ptinus tectus Boieldieu (Coleoptera, Ptinidae)
Authors: Duffy E. A. J.
Published: July 2009

An account is given of damage in Kent to a lead cable and its drum by larvae of Ptinus tectus Boield. The original infestation resulted from the accumulation of discarded food in the drum hub. The mature larvae, in order to pupate, bored into the hub of the drum and the sheath of the cable, thus producing innumerable excavations and some perforations in the sheath of several hundred feet of cable.
A revised Key to the Larvae of the Ptinidae associated with Stored Products
Authors: Hall D. W. , Howe R. W.
Published: July 2009

During the past 12 years, records of beetles of the family Ptinidae as pests of stored products in Britain have been increasing in frequency. Kloet & Hincks (1945) record 21 British species of Ptinids, but of these, three species, Ptinus palliatus, Perris, P. pilosus Mueller and P. latefasciatus Gorh., have not so far been recorded from warehouses or stored products and a furthertwo species, P. lichenum Marsh. and P. subpilosus Sturm have only rarely been recorded from such habitats. The importance of birds' nests as reservoirs of pests of stored products is being shown in a paper to be published shortly by Woodroffe and Southgate who carried out a survey of the fauna of the nests of birds associated with buildings. They found that the fauna of such a habitat was extraordinarily similar to that of warehouses in this country and that very large numbers of several species of Ptinids were present. The risk of this habitat being a possible source of many Ptinid infestations can be gleaned from the following list of species which they found:—

Ptinus tectus Boield., P. fur (L.), P. sexpunctatus Panz., P. pusillus Sturm, P. subpilosus Sturm, Eurostus hilleri (Reitt.), Niptus hololeucus (Fald.), Mezium affine Boield., Trigonogenius globulus Sol.
On Swarming and Mating in Anopheles aquasalis Curry
Authors: Senior white R. A. , Lewis G. , Lee P.
Published: July 2009

In Trinidad A. aquasalis swarms over open areas, mostly grass, and over drains and not over scrub vegetation.

Swarming commences at a light incidence not exceeding 5 foot,-candles.

Mating has been observed in 54 per cent. of the swarms, the fertilisation index of females captured in them being 65 per cent.

The lag between the first sight of a swarm and the first observation of a mating pairaverages 6·5 minutes, the light incidence at commencement of mating being no higher than an average of 0·8 foot-candles.