bluuebunny/crossref_metadata_2025 huggingface dataset:
The Identity of Phalaena chrysorrhoea, Linnaeus, 1758
Authors: Collenette C. L.
Published: July 2009

Rothschild in 1917 (Novit. Zool., 24, p. 355) stated that the above name, which had previously been accepted as the “Brown-tail” or “Cul brun”, really represents the “Gold-tail” or “Cul doré”. Although this opinion was discussed and agreed to by such writers as Barnes and Benjamin in 1924 (Proc. ent. Soc. Wash., 26, p. 213) and Joannis in 1928 (Encyc. ent., Sér. B III, Lep. 3, p. 99), the great majority of systematic works since published in Europe still adhere to the interpretation of P. chrysorrhoea as the Brown-tail.
A new Species of Encyrtidae parasitic in Coccus hesperidum, L
Authors: Compere Harold
Published: July 2009

The species described as new is placed in the genus Adelencyrtus, Ashmead, provisionally. The description is published at this time to provide a name, so that biological information concerning the species can be made a matter of record. The new species is most closely allied to Adelencyrtus. It differs from typical species of this genus with regard to the mandibles. In typical Adelencyrtus the mandibles are quadridentate, and the ventral margin is provided with a stout, cone-shaped seta. In the new species only the ventral tooth is distinct; the dorsal margin of the cutting edge appears as a wide truncation, which can scarcely be described as subdivided, and the ventral margin of the mandible lacks the stout conical seta. The most useful character for the identification of this species, and the one which reveals its relationship to Adelencyrtus most surely, is the distinctive male antennae. In this sex the antennal club is enormously cylindrically elongated, and the funicle is composed of two vestigial segments that are contained in a recess at the base of the club. Antennae of a similar kind have been described in the males of Habrolepis, Förster and Anabrolepis, Timberlake, two genera which are closely allied to Adelencyrtus. The males of Adelencyrtus have not been described.
The Climatology of Blowfly Myiasis
Authors: MacLeod John
Published: July 2009

The relationship of oviposition to weather, with a standard stimulus (4 per cent. ammonium carbonate), has been tested by a series of 134 exposures of a group of three sheep for one hour. 190 egg clusters were obtained, of which 169 were identified. With the exception of one cluster of L. caesar all were L. sericata.

There was a fairly close correlation (0·586) of oviposition with air-temperature. When the possible effect of other factors was eliminated, the correlation was little affected, showing that temperature was in itself responsible for the variations in oviposition. The lower critical limit of temperature was in the neighbourhood of 56°–58°F.

Solar radiation and oviposition had an apparent correlation, but this was found to be spurious, the effect being due to related air-moisture changes. At temperatures near the lower critical limit, insolation did not increase the oviposition rate, or lower its temperature threshold.

Humidity had an apparent inverse correlation with oviposition, but this also was an indirect effect, due to related temperature changes. Humidity showed a closer correlation when expressed as saturation deficiency than as relative humidity. Evaporation rate from a white atmometer sphere had only a low correlation with oviposition.

It is shown that the partial correlations of both saturation deficit and insolation with temperature effects eliminated, are insignificant, i.e. their apparent effects are due to related temperature changes. The multiple correlation coefficient for temperature humidity and insolation is practically identical with that for temperature.

Independent variations of insolation, i.e. variations not simultaneous with related temperature changes, had a significant effect on oviposition; for a given temperature, a high intensity of insolation was less favourable than a low, and this appeared to be a true insolation effect, and not due to associated humidity changes.

Independent variations of humidity had a suggestive but statistically insignificant effect, humidity tending to be inversely related to oviposition.

The regression of log oviposition on temperature, within the limits of this experiment, i.e. at temperatures up to 72°F., was linear. The slope was not significantly affected by the insolation and humidity factors, the total coefficient being 0·, and the partial coefficient 0·0428. These coefficients are the increase of the log number of egg clusters (plus one) for 1 degree F. increase, i.e. the oviposition rate increased in geometric progression for unit increase of temperature, the value (N+l) for egg clusters doubling itself for 7° increase.
Notes on the Tachinid Parasites of Cotton Stainers (Dysdercus spp., Pyrrhocoridae) in South Africa
Authors: Rainey R. C.
Published: July 2009

(1) Up to 35 per cent, of adult Dysdercus nigrofasciatus from a heavily infested late cotton crop at Barberton were found to be parasitised by Tachinid larvae at the end of the season.

(2) The predominant Tachinid species was Alophora nasalis; Bogosilla fasciata was present in smaller numbers, and appears to be more common in regions of higher rainfall.

(3) The development of the Tachinid larva within the stainer was a protracted process under local winter conditions, the larval period of A. nasalis being of the order of 2–3 months, and parasitised stainers were correspondingly long-lived.

(4) The possible economic significance of the parasites is discussed.
DDT residual Films
Authors: Parkin E. A. , Green A. A.
Published: July 2009

Exposure of house-flies to residual films of DDT, deposited on wall-board from kerosene solutions, has shown that the initial toxicity increases (1) as the deposit of DDT per unit area increases, and (2) as the concentration of DDT in the solution increases, although the amount of DDT applied is kept constant. In practice, DDT in kerosene should be applied to absorbent materials at as high a concentration as possible, consistent with reasonable coverage, in order to avoid much of the DDT being carried by the solvent into the substrate, where it is no longer available for contact with the insects.

With wall-board, a critical value for the product of concentration and deposit of DDT has been shown to exist, above which any mechanical stimulus, including movement of flies on the treated surface, will cause the DDT present in supersaturated solution to crystallise, with consequent marked increase in toxicity of the film. Under some circumstances, removal of the crystal carpet is followed by its partial regeneration. If the product of the concentration and deposit falls below the critical value, the residual film is at no time very effective and soon loses its initial toxicity.

The persistence of toxic films of DDT on wall-board has been shown, over an exposure period of 18 months, to be closely bound up with the crystallisation of the deposits and their powers of regeneration during intermittent exposure to flies.

This work has been carried out as part of the programme of research of the Pest Infestation Laboratory, and this account is published by permission of the Department of Scientific and Industrial Research.
An Experiment with DDT against Pests of stored Products
Authors: Jones B. M.
Published: July 2009

(1) The experiment was carried out on a short term basis due mainly to the limited time available for stored food products work, but it does show the possibilities of giving to the carrier medium an “adhesive” quality for the purpose of retaining an external layer of DDT upon bagged commodities.

(2) The increased activity at night of insects attacking stored food is interesting and the movement of insect densities in bags containing foodstuffs needs further detailed investigation. It does seem that a very high percentage of adult beetles will migrate to the surface of bags from inside the contained foodstuffs, and this makes it possible to achieve a fair measure of control by coating bags with a deposit of DDT.

(3) When a concentrate mist of a DDT emulsion-gum arabic solution is allowed to settle upon a bag surface, there is no detectable penetration of DDT through the sacking texture and therefore no danger of contaminating the contained foodstuffs.

(4) A deposit of such a DDT film, at a concentration rate of 50 mgm. DDT/sq.ft. upon a jute bag surface, remains appreciably toxic to Tribolium castaneum, Calandra oryzae, Rhizopertha dominica and Laemophloeus spp. for a period of approximately 60 days.
The Biology of the Parasites of Loxostege sticticalis, L., in North America—Meteorus loxostegei, Vier. (Braconidae, Meteorinae)
Authors: Simmonds F. J.
Published: July 2009

Meteorus loxostegei, Vier., is another important endoparasite of Loxostege sticticalis, L. It is perhaps second to Bracon vulgaris, Cress., in general importance as a control agent; it appears to be somewhat more variable in numbers than the latter species, but neither in the present work has been seen to reach the degree of parasitism shown by Phytodietus in Alberta in 1942.
Development ofEphestia elutella, Hb. (Lep., Phycitidae) on some natural Foods
Authors: Waloff N.
Published: July 2009

1. A selected stock bred on middlings and not diapausing at 25°C. was used in these experiments. None of the larvae reared on Manitoba wheat diapaused at 25°C., 70 per cent. R.H.; some diapaused at 21°C. and 17°C., 70 per cent. R.H. At these lower temperatures development was slower, more food by weight was eaten, and the moths were heavier.

2. More larval substance by weight was needed to produce a male than a female adult.

3. It was possible to subdivide natural foods into 3 groups: (i) Those on which no larvae diapaused at 25°C., 70 per cent. R.H. (ii) Foods on which a fairly low percentage of larvae diapaused at 25°C. 70 per cent. R.H. (iii) Foods on which most, or all of the larvae diapaused at 25°C., 70 per cent. R.H.; these foods were all characterised by a high content of starch. The possible cause is discussed.

4. Larvae moult 4 or 5 times on Manitoba wheat at 25°C. 70 per cent. R.H. Most of the larvae developing on this food under warehouse conditions could be allocated to 6 instars. At 25°C., 35·5 per cent. R.H. the number of larval instars is increased— one larva died in 12th instar.

5. The growth curves, obtained by measuring head capsules of successive instars roughly follow Dyar's law, although the ratio of increase falls off in the last 2 instars.

6. The prepupal stage inE. elutellacan be subdivided into five stages, on the basis of withdrawal of ocellar pigment, described inE. kühniellaby Kühn and Piepho. Only those prepupae which have reached stages four and five attempt to pupate after the head is ligatured, the other stages remain as “permanent larvae”.
A new systemic Insecticide bis (bis dimethylamino phosphonous) anhydride
Authors: Ripper W. E. , Greenslade R. M. , Hartley G. S.
Published: July 2009

Bis(bis dimethylamino phosphonous)anhydride is shown to be a systemic insecticide when sprayed on the leaves of numerous plants. The translation of it from one part of the plant to another, over distances varying from the thickness of a leaf to three feet, was shown with Aphis fabae, Myzus persicae, Brevicoryne brassicae, Macrosiphoniella sanborni and Pseudococcus citri.

Plants treated with it are shown to be toxic to 14 Aphid species, one Aleurodid, one mealy-bug, two Jassids and two species of red spider.

It is not found to be toxic to non-plant-sucking insects, notably predators and parasites. It is, therefore, a selective insecticide for the control of Aphids, and field experiments have shown that treatment with it gives plants prolonged toxicity to Aphids and allows the parasites and predators to keep in check any survivors or newly arrived individuals.

Non-selective organic phosphorus insecticides such as Parathion, Paraoxon and HETP give a high mortality, but the Aphid population builds up again very rapidly after treatment with them, leading, in many cases, to a heavier infestation than before.

Plants treated with bis(bis dimethylamino phosphonous)anhydride, on the other hand, keep free from Aphids for prolonged periods (2 to 5 weeks depending on the species of Aphid, the stage of growth of the plant and its physiological condition).
Studies on the Attractiveness of human Populations to Anophelines
Authors: Ribbands C. R.
Published: July 2009

Many female Anophelines wander into huts at random, possibly for shelter, and afterwards feed upon any suitable inhabitants.

This random wandering can be eliminated by pyrethrum spraying, and the acute discrimination of those Anophelines which enter primarily for food can then be demonstrated.

In sprayed huts there was a close relation between the number of men sleeping and the number of Anophelines attracted. The proportions attracted by 3 men and by 1 man were, for A. melas, 2·72; 1: A. gambiae, 2·38; 1: A. funestus, 2·28; 1. Discrimination was reduced at one period by the masking odour of cut and withering bush.

There were marked fluctuations in the attractiveness of individuals to Anophelines. On several occasions one or other of the men used as bait suddenly became much more attractive than his fellows, and remained so for several days.

The removal of a village increased by only 25–50 per cent. the proportion of mosquitos caught in two huts which were allowed to remain on the village site. This result indicates that most of the mosquitos which had infested the village had been attracted from a distance by the scent, and had not merely arrived in the vicinity of the village by chance.
Studies on the Toxicity of insecticide Films. II.—Effect of Temperature on the Toxicity of DDT Films
Authors: Pradhan S.
Published: July 2009

1. A series of exploratory experiments on the relationship between temperature and toxicity of DDT films to adults of Tribolium castaneum, and larvae of Plutella maculipennis, are described. The main conclusions with T. castaneum are:—

(a) When the insects are continuously kept on the film at different temperatures there is a higher kill at higher temperatures.

(b) When the insects are exposed to the film for about 24 hours at the same temperature and then kept away from it at different temperatures there is a higher kill at the lower temperature.

(c) When the insects are kept on the film at different temperatures for about 24 hours and then kept away from the film for reaction at the same temperature, there is a higher kill in those kept on the film at the higher temperature.

(a) and (b) above apply equally to larvae of P. maculipennis but (c) is reversed. The probable cause of this reversal appears to be the observed fact that at higher temperatures these larvae cover the film with much more silk thread and thus avoid contact to a greater extent than at lower temperatures.

2. A review of literature, in the light of the conclusions arrived at, indicate that many of the observations made upon the temperature-toxicity relationship can be accounted for by the following generalisations:—

(a) Insect resistance to poisons changes with temperature as do its other vital activities, increasing up to a critical degree and afterwards declining.

(b) The amount of poison reaching the site of action in unit time also varies with the temperature, generally but not always, increasing with its rise. Insect activity, especially locomotor and respiratory, may play an important part in these effects.

(c) The apparent effects of temperature on insecticidal action is the combination of these two factors, namely, resistance and pick-up.
Studies on Wheat Bulb Fly, Leptohylemyia coarctata, Fall
Authors: Gough H. C.
Published: July 2009

A quantitative survey of Wheat Bulb Fly (Leptohylemyia coarctata) was made in Yorkshire in 1945, and the distribution of the fly is discussed in relation to general observations and records in the years 1935–1946. The distribution is shown in themap (fig. 2).

One hundred and thirty-six fields on 86 farms were examined and Wheat Bulb Fly was present in over half of the farms and fields; in 8 fields (6 per cent.) it was present in moderately high numbers, and in 2 fields (1·5 per cent.) it was present in numbers sufficiently high to be likely to cause a failure in a bad wheat year. It was estimated that two or three thousand acres of wheat and rye in Yorkshire are likely to have a reduced crop as a result of Wheat Bulb Fly attack in an unfavourable season. Over half the dangerous area is near Selby. The only large area where Wheat Bulb Fly was virtually absent was the Yorkshire wolds.
Aircraft Applications of Insecticides in East Africa. III.—Atmospheric Turbulence in Woodland
Authors: Thompson B. W.
Published: July 2009

An effort was made to determine the best conditions to achieve maximum saturation and persistence of small droplet insecticide (5-200 microns droplet diameter) within a type of African woodland. The problem is entirely one of atmospheric turbulence within the woodland. No attempt was made, or is likely to be fruitful, to introduce a detailed or mathematical argument. The relevant factors pertaining to atmospheric turbulence were observed and in some cases were directly compared with simultaneous observations made in the open.

The absence of zero wind speeds, considerations of changing lapse rates, bi-directional wind vane records, and visual observations of smoke, all combine to suggest that when conditions of calm or light winds exist in the free air, there is, under moderately dense woodland canopies, an almost continuous and slow transfer of air between the canopy and the ground, these movements tending towards laminar or sheet flows. With stronger winds, eddying about the trees swamps these gentle movements and air motion becomes erratic and turbulent, although such turbulence is less the denser the canopy. During the daytime there is notable horizontal movement of air towards clearings where convection is at a maximum.
Aircraft Applications of Insecticides in East Africa. IV.—The Application of Coarse Aerosols in Savannah Woodland containing the Tsetse FliesGlossina morsitansandG. swynnertoni
Authors: Hocking K. S. , Parr H. C. M. , Yeo D. , Anstey D.
Published: July 2009

Attempts have been made to eradicate the tsetse fliesG. morsitansandG. swynnertonifrom two blocks of savannah woodland situated in the Central Province of Tanganyika.

The insecticides were applied from aircraft. Coarse aerosols were used, with mass median diameters of approximately 90 microns; droplet diameters varied from 4 microns to 250 microns approximately.

Eight applications of insecticides were made at intervals of two weeks. Each application was carried out at a nominal dosage of 0·25 gallons per acre, which was equivalent to 0·20 1b. per acre of the p, p'isomer of DDT or 0·03 lb. per acre of the γ isomer of BHC.

In the area treated with DDT it is possible that both species of flies were eradicated for a short period, but small populations were re-established there by immigrant flies. In the other block the reduction was not so great, but it is not considered that this was due to a lesser effectiveness of the BHC, but to a combination of circumstances that led to less effective applications.

Some general observations are made upon the use of aircraft for this sort of work, particularly in connection with the effect of meteorological conditions.
Observations on the Biology and Mass-breeding of Spalangia drosophilae Ashm. (Hymenoptera, Spalangiidae), a Parasite of the Frit-fly, Oscinella frit (L.)
Authors: Simmonds F. J.
Published: July 2009

A description is given of a technique for breeding the parasite Spalangia drosophilae Ashm. (Spalangiidae). Various biological “constants” such as fecundity and longevity were studied at 70°, 75° and 83°F., and the variation in the figures for these is given. The oviposition rate, efficacy of single matings, sex ratio, percentage in diapause, developmental period of both male and female at the different temperatures are also give.
Variations in the Wing Ornamentation of Anopheles funestus, Giles
Authors: Leeson H. S.
Published: July 2009

1. The ornamentation of the wings in Anopheles funestus, Giles, is variable.

2. Nine distinct arrangements of the wing scales were observed in a random sample of 1,084 individuals.

3. Nearly nine-tenths of the specimens occurred in one group, in which there were dark and pale forms.

4. Variations in wing markings are not solely related to sex or to habitat.

5. The pale form was more prevalent in the wet season and the dark form in the dry season.

6. It is suggested that further study may reveal whether the dark form is the hibernating variety and whether one form is more important as a carrier of malaria than the other, and that these details of wing ornamentation should be recorded in future.
The Nutrition of Mosquito Larvae, with special Reference to their Algal Food
Authors: Howland L. J.
Published: July 2009

1. Algae are ingested by many species of mosquito larvae and appear to form an important part of the food of these larvae.

2. The algae are digested in the gut, but the digestion is often by no means complete.

3. It is quite possible that the rôle played by the algae may also be assumed by other forms of organic matter, for larvae may be reared to maturity in solutions containing little or no algae.

4. Different algae react differently in the guts of the larvae, some being noticeably digested and some hardly at all.

5. Those algae which are digested the most are easily stained and are forms of low osmotic pressure.

6. Cytological investigation revealed no character that indicates that algae are an especially nutritious diet.

This work was carried out at the Farnham House Laboratory of the Imperial Institute of Entomology, Buckinghamshire, under the guidance of Dr. P. A. Buxton, to whom my thanks are due.
Studies on the Galleries of the Bark-beetles
Authors: Trägårdh Ivar
Published: July 2009

The galleries of the bark-beetles are as a rule such characteristic features of the different species that sometimes these are more easily recognised by the shape of their galleries than by their own structure, as, for example, in the case of the two pine-beetles, Blastophagus piniperda and B. minor, in which the distinguishing features of the insects cannot be discerned without the help of a good pocket-lens. But, on the other hand, the galleries of many species are subject to a certain amount of variation and show typical modifications which are responses to various external factors, such as the size of the trunk or of the branches, the thickness of the bark, and the orientation of the trunk, viz., whether the tree is standing or felled.
New Species and Host Records of Braconidae
Authors: Wilkinson D. S.
Published: July 2009

None of the species so far described under Urosigalphus is known to me, but Cameron's Rhyssosigalphus is clearly a synonym of Ashmead's interesting genus.

Szépligeti (Genera Insectorum, fasc. 22b, 1904, p. 90) synonymised Urosigalphus under Sigalphus, Latr. (i.e., Triaspis, Hal.); I do not know what authority he had for his action, which was ignored by subsequent writers (Crawford, 1907, 1914; Cushman, 1922).
Mosquito Notes.—X
Authors: Edwards F. W.
Published: July 2009

The following remarks are based chiefly on the revision of the East Indian species of the subgenus Mansonioides just published by J. Bonne-Wepster (Geneesk. Tijd. Ned.-Ind., Deel 70, pp. 940–966, Sept. 1930). A re-examination of the British Museum collection in the light of Mrs. Bonne's work has shown that certain points need elaboration or correction.
New injurious Curculionidae (Col.)
Authors: Marshall Guy A. K.
Published: July 2009

Head continuous with the rostrum, not constricted behind the eyes, which are moderately convex, the forehead as broad as the base of the rostrum. Rostrum narrowing from the base to the antennae ; mandibles squamose, mentum bare. Antennae with the scape exceeding the hind margin of the eye, the distal joints of the funicle elongate, joint 2 longer than 1. Prothorax with the base depressed, at a lower level than the apical margin, sinuate or bisinuate. Elytra obovate, widest behind the middle, with or without shoulders. Legs with only the front femora armed with a small sharp tooth ; front tibiae only finely denticulate and with the dorsal edge curved, hind tibiae with the corbels enclosed and not ascending the dorsal margin ; joint 2 of hind tarsi not transverse ; front coxae nearer to anterior margin of prosternum ; claws free. Sternum with the metasternum not longer than a median coxa. Venter with the intercoxal process about as wide as a hind coxa.
The Mediterranean Fruit-fly (Ceratitis capitata, Wied.) in the Jordan Valley
Authors: Grünberg A.
Published: July 2009

The fruit-fly damage in the Upper Jordan Valley is limited to the southern belt of Citrus plantations ; further north the fly's activity remains, so far, restricted. There is a permanent fluctuation in the fruit-fly's population density according to ecological conditions, which may change from year to year. This fluctuation is of an irregular character. In years of severe infestation the damage attains 10–15 per cent. of the total crop ; there are seasons, however, when the damage is practically negligible. There is constant danger in the fruit-fly situation, because this fly is able within a short time to increase immensely its population density, if environmental conditions are suitable.

The number of hosts is relatively small in the Jordan Valley ; the Citrus plantations supply sufficient food during 7–8 months, and there is a relatively long summer quiescent period (about 2 months) with an extremely low fruit-fly population ; during the remaining period figs, grapes and other occasional plants serve as hosts.

The fruit-fly is spread chiefly by mechanical agents (wind and transport of infested fruits).

There are 8 generations during the year in the Jordan Valley.

There are two peak infestation periods (October and April-May) and two quiescent periods (winter and late summer).

Fruit-fly control under present cultural conditions should be confined to peak infestation periods only, as unfavourable climatic conditions are responsible for an extremely high mortality of fly later in the winter and in summer.
Distribution and Fate of Anopheles gambiae and A. funestus in two different Types of Huts treated with DDT and BHC in Uganda
Authors: Wilkinson P. R.
Published: July 2009

Wood-and-fibre-board huts fitted with one-way entry and exit traps were sprayed with DDT and BHC wettable powders at dosages 3·3 and 1·5 times the dosages reported by Muirhead Thomson in Tanganyika. Mud huts similar to his design were sprayed at 1·4 times his dosage of DDT and 1·1 times his dosage of BHC. Catches of Anopheline mosquitos continued for 16 weeks.

In the first-named huts kills of A. gambiae were 97 per cent. for both treatments. Kills of A. funestus were 100 per cent. and 97 per cent. for DDT and BHC respectively.

In the mud huts kills of A. gambiae were 62 per cent. and 98 per cent. for DDT and BHC respectively. For A. funestus kills were 78 per cent. and 93 per cent. in the same order.

The advantages claimed for the wood-and-fibre-board huts include :—

(a) freedom from ants, which may remove dead mosquitos.

(b) ease of catching live adult mosquitos.

(c) rigid construction of exit trap.

(d) lack of adventitious exits other than exit trap.
The Entomology of Swollen Shoot of Cacao. II.—The Bionomics and Ecology of the Species involved
Authors: Strickland A. H.
Published: July 2009

A method for the routine quantitative estimation of mealybug populations on cacao trees is described and the results obtained from 24 successive monthly samples are tabulated.

The quantitative results obtained are of such variability that only gross differences in population density are shown as statistically significant.

From a series of analyses based on the survey data the following conclusions have been reached with regard to P. njalensis, the most important mealybug vector of swollen shoot virus :—

(a) The species is almost invariably attended in the field by Crematogasterine ants, the most important ant species building protective carton tents over the mealybug colonies.

(b) Crematogaster density is closely correlated with mealybug density and the ants construct their carton tents in relation to the numbers of mealybugs to be protected. Some of the arboreal Crematogasterine groups investigated are shown to be consistently associated with higher mealybug populations, and to have a more advanced tent building habit, than others.

(c) Tree to tree variation in mealybug density is shown to be largely dependent on the identity of the dominant ant group.

(d) No direct correlation is apparent between mealybug density and incidence of swollen shoot though populations in areas devastated by virus are usually smaller than in areas in which virus is actively spreading.

(e) The factors of importance in the natural control of P. njalensis populations have been discussed in some detail. It is clear that the species is maintained by ant protection at a density level considerably above that prevailing amongst closely related pseudococcid species which are not ant attended to the same extent. At this level of “ protected steady density ” balance is maintained partly by losses during crop harvesting, and partly by swollen shoot rendering the host plants unsuitable as feeding stations. It is concluded, however, that natural enemies must, in the last analysis, be responsible for maintaining balance.

(f) Since the protected density of P. njalensis is a direct result of ant associations it follows that factors tending to control the attendant ant species will have a delayed effect on mealybug density. In this respect it is believed that Oecophylla, which is strongly negatively correlated with Crematogaster spp., is of importance. Any attempts that may in the future be made to control the mealybugs by killing the ants will have to be designed as specific against the Crematogasterini and non-lethal to Oecophylla and the other large predatory ants common on cacao.
Studies on the Responses of the Female Aëdes Mosquito. Part II.—The Action of Liquid Repellent Compounds
Authors: Sarkaria D. S. , Brown A. W. A.
Published: July 2009

A number of liquid mosquito repellents were assessed for vapour repellency power in an olfactometer mounted in a very large cage filled with females of Aëdes aegypti. They were also tested for their knockdown power in fumigation bottles. Their vapour pressures were determined by the Ramsay-Young method.

All the liquids showed vapour repellency, and in 39 out of the 42 tested this effect was highly significant. The highest vapour repellency ratings were shown by compounds already known to be the most effective repellents.

Although the more volatile compounds such as citronellal tend to show the highest repellency ratings, nevertheless compounds of low vapour pressure such as indalone, DMP and isobornyl morpholinoacetate may also show high vapour repellency. It is concluded that vapour repellency, although in the first instance dependent upon volatility, can vary independently of vapour pressure, so that compounds may be found which afford not only a long protection period due to their nonvolatility, but also a high vapour repellency due to the potency of the comparatively few molecules that are volatilised.

The vapours of most of the repellents were found to induce knockdown of mosquitos, but there was no correlation between the speed of this process and the vapour repellency of the compounds.
Physiological Investigations into the Heart Function of Arthropods
Authors: Krijgsman B. J. , Krijgsman-Berger Nelly E.
Published: July 2009

Perfusion of the isolated heart ofPeriplaneta americanawith caffeine, digitalin, acetylcholine, nicotine and lobeline shows that the pacemaker of this heart is different from the “ myogenic centre ” of the vertebrate heart.

The action of strychnine, morphine and apomorphine on this heart preparation affords evidence of the existence of a neurogenic pacemaker.

This pacemaker is stimulated by suitable concentrations of acetylcholine, nicotine, lobeline and pilocarpine, while it is inhibited by atropine. Acetylcholine and tetraethyl pyrophosphate show a synergistic action. Atropine and tetraethyl pyrophosphate, like acetylcholine and curare, show an antagonistic action. These results prove that the neurogenic pacemaker possesses cholinergic properties.

Adrenaline stimulates the insect heart and ergotamine inhibits it, thus suggesting that the insect heart probably also has adrenergic properties.

On the basis of the present work and the results obtained by other investigators, a theory is put forward that the heart mechanism of most arthropods consists of a neurogenic pacemaker with adrenergic properties, controlled by a cholinergic accelerating nerve. This mechanism bears some resemblance to the sympathetic nerve system of vertebrates.

Rotenone strongly counteracts the action of acetylcholine, tetraethyl pyrophosphate, nicotine, lobeline, pilocarpine and digitalin on the insect heart. Its point of action, however, remains obscure at the moment.

The opposing action of rotenone and tetraethyl pyrophosphate is an indication that a combination of these insecticides for pest control is not to be recommended.
Pink Bollworm, Platyedra gossypiella (Saund.), as a Pest of Cotton at Zeidab, Northern Sudan
Authors: Darling H. S.
Published: July 2009

Losses from Pink Bollworm (Platyedra gossypiella) and from Spiny Bollworm (Earias insulana) were studied in the American Upland cotton crop grown on Zeidab pump irrigation scheme in the Northern Province of the Sudan. In 1948, a year of normal attack, 12·9 per cent. of the estimated potential yield was destroyed by bollworms. Pink Bollworm was responsible for 10·7 per cent. or a loss of 135 pounds of seed cotton per acre. Spiny Bollworm damaged 2·2 per cent. or 28 pounds per acre.

Four-fifths of the total yield is derived from the bottom crop which is harvested before the end of September and consists of high grade seed cotton. The other fifth is produced as a top crop and consists of low grade seed cotton ripening in October and November. Only 3·5 per cent. of the bottom crop is lost on account of Pink Bollworm as against 33·3 per cent. of the top crop. The corresponding figures for Spiny Bollworm are 1·6 per cent. and 4·1 per cent.

Some factors influencing the extent of pink bollworm attack are outlined. The Zeidab crop escapes serious damage through rapid maturity and even growth. Correct agricultural management is of great importance. Attack by Laphygma exigua in the seedling stage may result in increased damage by Pink Bollworm in the ripening crop.

The origin of the initial pink bollworm infestation is discussed. Available evidence, which is not conclusive, suggests that local carry over of the dead season may not be sufficient to account for the initial infestations observed in the crop.

Atmospheric water vapour saturation deficit appears to influence the duration of larval diapause in Pink Bollworm in the northern Sudan. Maximum emergence of moths from resting larvae in three areas occurs at or near the lowest saturation deficit of the year. The possibility is discussed that the degree of fixity of the diapause may be related to the gradient of the saturation deficit curve during the development of the resting larvae in the crop, a rising curve being associated with a well fixed diapause which lasts until the saturation deficit falls, and a falling curve being associated with a poorly fixed diapause which does not last but begins to break at once.
A new Species of Afrius (Hem., Pentatomidae) predacious on Schematiza cordiae Barb., in Mauritius
Authors: Miller N. C. E.
Published: July 2009

Specimens of the new species here described were received by the Commonwealth Institute of Entomology, London, from Mr. J. R. Williams, Entomologist of the Department of Agriculture, Mauritius, who reported it to be predacious on the Galerucid, Schematiza cordiae Barb., which has been introduced there to control the weed, Cordia macrostachya.
The Rôle of Aëdes leucocelaenus in the Epidemiology of Jungle Yellow Fever in Brazil
Authors: Kumm Henry W. , Cerqueira Nelson L.
Published: July 2009

Aëdes leucocelaenus transmits yellow fever virus readily in the laboratory and has twice been found infected in nature.

Except in south Brazil this species is much less common than Haemagogus spegazzinii among day-biting sylvan mosquitos captured with human bait.

A. leucocelaenus has a wide distribution throughout the forested area of this country.

As a natural vector of jungle yellow fever in the northern part of Brazil it is of secondary importance when compared to H. spegazzinii.
Seasonal Variation in the Incidence ofTrypanosoma vivaxinGlossina palpalis(R.-D.)
Authors: Squire F. A.
Published: July 2009

Over 3,000 examples ofG. palpaliswere age-grouped and dissected forT. vivaxover a period of a year. The incidence of infection throughout was highest in Age-group 3 and lowest in Age-group 1. There was a marked seasonal fluctuation, the incidence being highest during the months of heavy rainfall,i.e., August to October, and lowest in the driest.

It has been suggested that the rise in the rate of infection during the rains is merely due to the increasing average age of the fly population, but by the method of age grouping it is shown that this is not the case.

The degree of infection inG. palpalisin Sierra Leone is comparable with that ofG. tachinoidesin Nigeria.

It is not thought that the seasonal variation in the incidence of infection can be ascribed to changes in the type and abundance of food. The true cause of the fluctuating incidence of infection like the source of infection is unknown.

The failure to recognize seasonal differences in the rate of infection has led to some important practical misconceptions.
The Effect of Parathion Dusts on Eurygaster integriceps Put. (Hem.)
Authors: Talhouk A. S.
Published: July 2009

Eurygaster integriceps is a serious pest of wheat in Syria against which various methods of control have been tried.

Laboratory tests with a 0·8 per cent. parathion dust applied at the rate of 0·1 mg./sq. cm. are described.

Three sets of field experiments were carried out with 0·75 per cent. and 0·8 per cent. parathion dust. Applied at a rate of 75 kg. /ha. these were very efficient but not economical. Applications of 0·8 per cent. dust with a knapsack duster at between 15 and 17·5 kg. /ha. gave about a 20 per cent. reduction in the infestation. A larger experiment in which 0·75 per cent. dust at a rate of 48 kg. /ha. was applied to a hectare of wheat, by means of a 6 h.p. duster mounted on a Jeep fitted with a drag sheet, gave a 70 per cent. control.
Studies on Beetles of the Family Ptinidae
Authors: Howe R. W.
Published: July 2009

An account is given of an attempt to estimate changes in the rate of egg laying in a warehouse and in an unheated outbuilding at the laboratory. Small samples of food were placed on pieces of newspaper on the floor, and were renewed regularly, weekly or fortnightly in the warehouse and daily at the laboratory. Larvae were bred from these food samples and counted.

The rate of oviposition was found to depend on temperature, especially in winter, and on relative humidity, especially in summer. It was seldom cold enough indoors, in unheated premises, to prevent oviposition entirely for more than a few days at a time, 5°C. being the approximate minimum temperature for oviposition. It was never so dry at the laboratory that egg laying stopped but this did happen at the warehouse in July, 1946. Free drinking water is necessary for continued oviposition and this was available from rain in both buildings.

Darkness causes an increase in activity and in oviposition and most of the eggs in the foods supplied were laid at night. Foods placed near the daytime hiding places of adults were most used for oviposition.
Four new Species representing two new Genera of Bryocorinae associated with Cacao in New Britain (Hemiptera, Miridae)
Authors: China W. E. , Carvalho José C. M.
Published: July 2009

Thanks to the courtesy of Mr. G. S. Dun, Government Entomologist to the Territory of Papua and New Guinea, we have been able to study three interesting new species of Mirids found damaging cacao plants in New Britain. The first was discovered by Mr. Dun early in 1950 in abundance at Kabeira Plantation about six miles from the Lowland Experimental Station at Keravat where considerable damage had been done to the crop. This species was at first thought to be the West African Bryocoropsis laticollis Schumacher, 1917, which might have been accidentally introduced into New Britain. Closer investigation showed that it belonged to a distinct genus and species (Parabryocoropsis typicus, gen. et sp. n.). In September 1950, Mr. Dun found a second species attacking an isolated block of Cniollo cacao at the Keravat Experimental Station. On examination this proved to belong to still another genus and species (Pseudodoniella pacifica gen. et sp. n.).
Review of the Biological Control of Coccids on Coconut Palms in the Seychelles
Authors: Vesey-FitzGerald D.
Published: July 2009

Reference is made to the several species of scale insects which were pests on coconuts and to the Coccinellids which were introduced to combat them.

The introduction and life-history of Chilocorus nigritus is described.

The survival of the introduced Coccinellids and the part each has played in controlling the several species of scale is noted.

The habits of some indigenous Coccinellids are recorded.

The coconut-feeding Coccids of the Seychelles are listed and their economic role mentioned.

The incidence of “sooty-mould” and the species of Coccids responsible for its growth are discussed.

An estimate is made of the value of the control effected by the Coccinellids in terms of increased copra production.
The Effect of Hydrogen Cyanide on the Eggs of the Common Furniture Beetle, Anobium punctatum (Deg.)
Authors: Bletchly J. D.
Published: July 2009

The effect on the eggs of the common furniture beetle, Anobium punctatum, to fumigation with hydrogen cyanide at a concentration of 4·25 mg./litre and four concentration/time exposures, varying from 4·3 to 42·5 mg. hr. per litre has been determined. Complete mortality was obtained in all cases. Comparison with data available for larvae show that the eggs are less resistant, from which it is concluded that commercial treatments adequate for infested wood will also kill eggs.
The Susceptibility to DDT Dust of Coleoptera infesting Stored Products
Authors: Parkin E. A.
Published: July 2009

The resistance to a 5 per cent. DDT powder of 36 species of adult and larval Coleoptera which infest stored products has been determined. The species are grouped according to the time required to effect 95 per cent. kill. In the data for adults, the slopes of the probit regression lines were not significantly correlated with the log-times for 50 per cent. kill. No obvious connection could be seen between the degree of resistance to the insecticide and size, activity, hairiness, etc., but larvae tended to be much more resistant than the corresponding adults.
The Rate of Digestion of Blood Meals of various haematophagous Arthropods as determined by the Precipitin Test
Authors: Weitz B. , Buxton P. A.
Published: July 2009

The period of digestion of the blood meal of 10 different blood-sucking arthropods which had been artificially and naturally fed on known hosts was studied by means of specific precipitin tests.

A large proportion of positive feed (80–100 per cent.) was found with midges and mosquitos up to 24 hours, whether naturally (Anopheles aquasalis) or artificially fed (A. maculipennis atroparvus, Culex molestus, Culicoides nubeculosus, Aëdes aegypti).

Tsetse flies showed greater differences between the rate of digestion of captive flies (Glossina morsitans), which showed 90–100 per cent. positive feeds at 3 days after the experimental blood meal, and wild flies (G. swynnertoni) which showed only 28 per cent. positive meals after a similar period of digestion. Arachnids showed both the longest period of digestion, more than 6 months for Ornithodoros moubata and also the shortest period as represented by Bdellonyssus bacoti (about 1 day).

Cimex lectularius showed 90 per cent. positive feeds after 10 days.
Studies on Beetles of the Family Ptinidae IX.—A Laboratory Study of the Biology ofPtinus tectusBoield
Authors: Howe R. W. , Burges H. D.
Published: July 2009

Ptinus tectusoccurs on a large range of foodstuffs in all types of storage places, in warehouse refuse and in the nests of birds. It is widely distributed in cool and temperate areas but is very rarely found in hot climates. In Britain it can survive the winter when exposed in a Stevenson screen to outdoor shade conditions.P. tectusis seldom found on imported cargoes inspected aboard ship, but many British warehouses carry a population of the species resident in the fabric of the premises.

The larva is able to bore through cellophane, card and textiles and can also make impressions on wood. The fully fed larva spins a cocoon on the fabric of containers and buildings. Holing of packages and contamination by silk of high grade produce form the chief economic losses caused by the species, but occasionally large populations are found, sufficient to reduce the food value of produce. Unlike the larvae, adult beetles cannot penetrate sound linen bags, but lay eggs through the meshes.

In a series of consecutive experiments, performed identically as far as possible, variations in the length of developmental period and in emergence weight of adult beetles were greater than would be expected by chance. The variations could not be related to any single observed or suspected inconsistency of technique or environment. It is desirable therefore to conduct comparative experiments simultaneously.
Some Notes on the recorded Distribution of Old World Species of Ornithodoros (Acarina)
Authors: Leeson H. S.
Published: July 2009

These notes are the result of an examination of the literature and are concerned with geographical distribution. The Review of Applied Entomology, Series B, and the Tropical Diseases Bulletin were consulted and many papers were seen in the original; references to a selection of the more important of these is appended herewith. Of the ticks of the genus Ornithodoros occurring in the Old World about 40 names appear in published papers; of these about 20 seem to be valid species and five are well known and readily recognised: erraticus, lahorensis, moubata, savignyi and tholozani.
Studies of British Anthomyiid Flies
Authors: Miles Mary
Published: July 2009

Onions and related crops are attacked by the onion fly, D. antiqua (Mg.), and by the bean seed flies, D. cilicrura (Rond.), and D. trichodactyla (Rond.). The eggs, larvae and puparia of the three species are similar in form, and the only morphological difference so far observed is in the number of processes of the anterior spiracles of the larvae. In D. antiqua the anterior spiracles have 10–13 processes; in D. cilicrura and D. trichodactyla, the immature stages of which cannot yet be distinguished from each other, the anterior spiracles have 5–8 processes.

Onion flies and bean seed flies have different habits and consequently the circumstances of their attacks differ. The onion fly is a specific feeder and its attacks are likely to be serious in spring and early summer. The bean seed flies are general feeders and attack on onions in spring is unlikely because the preparation of the soil, which attracts the flies, is usually completed before they emerge from the over-wintering puparia. Bean seed fly attack on onions is likely to take place in August when onions for bunching are sown. The preparation of the seed bed attracts the flies of the third generation from the surrounding crops and the soil may become heavily infested with larvae which subsequently destroy the germinating seeds. In August and September it is unlikely that young crops will attract onion flies from the mature crops on which they are established.