bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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).
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.