bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Uptake of DDT and other lipophilic Particles by Blowflies walking over Deposits
Authors: Gratwick M. 
Published: July 2009

Estimations have been made of the weight of material accumulated by adults of Phormia (Protophormia) terraenovae R.-D. from deposits of DDT and other lipophilic particles on different types of substrate on which the flies were exposed.Uptake of dry DDT particles is shown to be similar to that of dry lipophilic dye particles of similar size so that conclusions on the contamination of insects by dry lipophilic dyestuff may be extended to contamination by DDT dust.The presence of oil greatly reduces the uptake of DDT particles from a fibrous substrate, the uptake decreasing logarithmically with increase in the amount of oil applied to the substrate. The viscosity of the oil has no more than a very small effect on the uptake of lipophilic particles from oily deposits and the solubility of the particles in the oil has no significant effect.A reduction in the uptake of dry lipophilic particles from filter paper and from a hard, waxy substrate occurs when a wetting agent solution is applied immediately before the particles. When the particles are applied after the drying of the wetting agent on the substrate, a reduction in uptake also occurs on the non-absorbent, waxy surface, but is not so large as when the particles are applied before drying of the wetting agent. No reduction in uptake occurs on the absorbent substrate under these conditions.On the basis of the experimental results the variations in the adhesion of lipophilic particles to substrates are discussed.While differences in the affinity of particles for substrates of different types cause variations in adhesion, the physical structure of the surface may be more important in determining the amount picked up from it. The presence of oil or wetting agent on the surface increases adhesion, probably by increasing both the affinity of the lipophilic particles for the substrate and the area of contact between the particles and the substrate.
The Contamination of Insects of different Species exposed to Dust Deposits
Authors: Gratwick M. 
Published: July 2009

The quantities of lipophilic dyestuff picked up by specimens of five insect species, namely Vespula vulgaris (L.), Feronia madida (F.), Rhagonycha fulva (Scop.), Dysdercus fasciatus Sign, and Notostira erratica (L.), in their first few steps on a dust deposit of the dyestuff have been estimated. The uptakes per step by insects of different size and structure were shown to differ only slightly. While the uptake was found to be greater for the larger insects, the smaller insects picked up more particles per unit body weight at each step.The ratios of the actual amounts (estimated by a colorimetric method) picked up by the different pairs of legs are similar for all the insects that have been studied and in all cases the hind legs were shown to pick up an amount at least equal to the sum picked up by the fore- and middle legs.
Seasonal changes in larval populations of Leptoconops becquaerti (Kieff.) (Dipt., Ceratopogonidae) in Jamaica, with observations on the ecology
Authors: Linley J. R. 
Published: July 2009

Seasonal changes in two natural larval populations of Leptoconops becquaerti (Kieff.), a biting sandfly of economic importance in the Caribbean area, are described from studies in 1963–64 near Montego Bay. Aspects of the ecology arising from these observations are included. An attempt is made to relate the seasonal changes in the larval populations to the seasonal distribution of adults, and in addition, a separation is made between the autogenous and anautogenous forms of the insect.Larvae of both autogenous and anautogenous forms lived together in the same breeding sites and did not appear to differ in their spatial distribution. The two populations studied consisted mainly of larvae associated with the small, autogenous form. Drastic reduction in both populations occurred following events such as wave action and heavy rain that had a mechanical action on the sand in which the larvae lived. The distribution of both forms of larvae was dependent upon the surface elevation with respect to the level of free soil water, since this to a large extent, owing to the upward capillary movement of water, governs moisture content of the surface sand. Elevations between about 9 and 17 in. appeared to be the most favourable. Permanent breeding probably does not occur in sand at elevations greater than about 21 in., though temporary breeding may occur at higher elevations if some other source of moisture (e.g., frequent rain) is available.In the autogenous form, a prolonged period was spent in the third larval instar. This was probably induced by some factor associated with lack of moisture in the sand, and appears to be broken (causing completion of development) by an effect of increased moisture content after heavy rain. This phenomenon probably does not occur in the anautogenous form.
The timing of adult eclosion in blackflies (Dipt., Simuliidae) in West Cameroon
Authors: Disney R. H. L. 
Published: July 2009

A description is given of an artificial stream for studying pupation times and pupal periods of Simulium spp., of emergence traps for studying emergence times in rivers, and of a convenient arrangement for rearing batches of pupae in the laboratory.S. damnosum Theo., S. kenyae De Meillon and S. unicornutum Pomeroy pupate mainly by day, each species having a characteristic period of peak pupation.In S. damnosum and S. kenyae the time of pupation influences the pupal period, and for these and other species the pupal period is prolonged by lower temperatures. The pupal period is partly independent of these influences in so far as emergence by night is normally avoided.The timing of adult eclosion is influenced by the temperature on the day of eclosion. On warm days (midday temperature of the river 24·1–28°C) S. damnosum and other forest zone species show a peak of emergence between 06.00 and 09.00 h, while on cool days (midday temperature of the river 20·1–24°C) the peak is delayed until 09.00 to 12.00 h. On artificially cold days (refrigerator temperature 16–20°C), the peak is shifted to the late afternoon.The study of the timing of adult eclosion from pupae brought into the laboratory is complicated by the fact that the normal pattern of emergence is liable to disturbance.In the laboratory a seasonal fluctuation in the sex ratio of emerging flies occurred in S. damnosum.
A study in East Africa of the bean flies (Dipt., Agromyzidae) affecting Phaseolus vulgaris and of their natural enemies, with the description of a new species of Melanagromyza Hend
Authors: Greathead D. J. 
Published: July 2009

Examination of infested bean plants (Phaseolus vulgaris) showed that “bean fly” in East Africa consists of three species, Melanagromyza phaseoli (Tryon), M. spencerella sp. n. and Ophiomyia centrosematis (de Meij.). M. spencerella is described, and notes are given on the life-cycle, host-plants and distribution for all three species. Their importance in East Africa is discussed and it is concluded that M. spencerella is the most damaging because it oviposits and feeds in the hypocotyl, is frequently the most abundant species and is less effectively parasitised. Bean plants able to produce adventitious roots freely are able to grow away from the important early attack in the stems. Published work on chemical control measures is summarised.The parasite complex associated with bean fly in East Africa was studied, and notes are given on the species present, the recognition of their early stages, their host ranges and abundance. Parasitism is discussed in relation to the infestations found on beans, with special reference to Opius melanagromyzae Fisch., the most important parasite of M. phaseoli, and Eucoilidea sp., the most important parasite of M. spencerella. It is concluded from graphical analysis that O. melanagromyzae is density-dependent and an important factor in limiting M. phaseoli populations in East Africa. Eucoilidea sp., on the other hand, shows signs of delayed density-dependence and is less effective in controlling its principal host. O. melanagromyzae has recently been sent to Hawaii for release against M. phaseoli; some field recoveries have been made already.
On the Control of Antestia lineaticollis, Stål (Hem., Pentatom.) on Coffee in Kenya Colony
Authors: Le Pelley Richard H. 
Published: July 2009

1. The damage done to coffee by Antestia lineaticollis, Stål, is shortly described and notes on its life-history are given.2. It is parasitised in the egg-stage by two important species of Proctotrupoid parasites, the percentage of parasitism usually varying around 80 per cent. and in one case quoted being as high as 91 per cent.3. Of the control measures employed, contact-spraying has not proved satisfactory; hand-picking of the bugs and egg-clusters and liberation of the parasites are widely practised and, though troublesome and expensive, are of considerable value; another method of value and widespread adoption has been called the “poison-baitspray” method. This is described in detail; it consists in the application of a stomach-poison in the form of a solution of sodium arsenite and sugar to the tree by spraying. Laboratory observations show that the insect imbibes the poisoned solution by lifting the proboscis into small drops on the leaf surface, and there is a definite kill due to the use of this poison.4. In Kenya, its use commercially, while often of proved value, has not been invariably successful. Experiments showed that the egg parasites of the bug were strongly attracted by the poison spray and quickly died after feeding on it. It is suggested that this may be the cause of some of the unsuccessful results.
Sodium Fluosilicate as a Poison against the Hoppers of Locusta migratoria migratorioides, R. & F., in Nigeria
Authors: Golding F. D. 
Published: July 2009

(1) For the first time sodium fluosilicate has been tested as a poison against the hoppers of Locusta migratoria migratorioides. This poison was found to be as effective as sodium arsenite in baits when used at the same concentration, viz., 2·44%, but was slower in its action. When guinea-corn bran is used as the carrier it is necessary to add salt to the bait as an attractant; the reason for this is not known, fluosilicate baits containing sawdust, chopped hay and chaff from cereal crops respectively were effective without salt being added.(2) From an examination of the results of experimental work on the relative toxicities of sodium fluosilicate and arsenical compounds to domesticated animals in various parts of the world, it is concluded that the former is less toxic to stock, but that the increased degree of safety acquired through the use of sodium fluosilicate is not so great as is popularly supposed. A definite advantage of baits containing fluosilicate is that they are repellent to many animals, whereas baits containing sodium arsenite are attractive to stock.
Ecological Studies on Aphides infesting the Potato Crop
Authors: Davies W. Maldwyn 
Published: July 2009

1. Ecological studies on aphides attacking potatoes were commenced in 1928 with a view to elucidating certain problems of entomological interest and also the role of these insects as vectors of disease. The species include, Myzus persicae, Sulz., Macrosiphum gei, Koch, and Myzus pseudosolani, Theo.2. The present study is confined mainly to the infestation of aphides on potatoes at a selected centre which is described.3. Solitary apterous viviparous females were in a majority on potatoes during the period of initial infestation in early June. Their presence is explained by (1) the overwintering of aphides on weeds and field plants, (2) the first few alatae depositing single nymphs and then migrating, (3) infection from infested seed.4. The maximum infestation was reached during mid-July, when 86 per cent. of the leaves were infested and there was an average of 2·8 aphides to a leaf. The infestation was below that of the previous three years. Macrosiphum gei bred up rapidly, at first on the flower-heads, and was the predominant species, its decline in numbers being equally rapid. Myzus persicae increased more slowly and did not reach such numbers, but the maximum was maintained longer and the disappearance of the species was delayed. Myzus pseudosolani was only taken in August and then in small numbers.5. An estimate of the intensity of the aphis population is attempted, and in the present moderate infestation of 2·8 aphides to a leaf it was of the order of 2,000,000 aphides to an acre of potatoes.6. A technique was established to ascertain the movement of aphides within the crop. Weekly records on observational leaves revealed that 100 per cent. of the aphides moved their site and at least 84 per cent. of each species moved from leaf to leaf within the weekly period. Daily records during the period of maximum infestation showed that 84 per cent. of Macrosiphum gei and 73 per cent. of Myzus persicae changed site within 24 hours, and of these at least 50 per cent. moved from the leaves upon which they had been observed.7. It was noted that no attempt was made to maintain large local colonies, for the movement of both adults and nymphs was frequent, and observed colonies soon dispersed. The extended infestation of Myzus persicae is discussed with reference to its establishment on field plants, other than potatoes, during the autumn and winter.
Ecological Notes on theSirexWood Wasps and their Parasites
Authors: Hanson H. S. 
Published: July 2009

1. The ecological study ofSirexand its parasites was begun in 1927 and continued while making large-scale collections of the parasites for shipment to New Zealand with the ultimate object of the control ofSirex noctilio, a species of woodwasp which has been established in the Dominion for many years.2. A brief outline of the life-cycle ofSirexand the parasites is given. The difference in the method of attack by the parasites on the host is described, and some points of interest in connection with insect behaviour are discussed.3. The methods of collection are described and particulars given about the number of parasites collected.4. The inter-relationship of the host and parasites is discussed. It is shown that a single generation ofSirexcan support three generations ofRhyssaand one generation ofIbalia, and that the effects of parasitism byRhyssaare cumulative. The percentage of parasitism byRhyssacannot, therefore, be calculated on the results of any one year.Rhyssais intrinsically superior toIbaliaand super-parasitism ofIbaliabyRhyssais of very frequent occurrence. It is shown that the figures for parasitism byIbaliaobtained by the dissection ofSirexlarvae collected from a number of logs, over a period including summer months, are liable to be very misleading.
Problems concerning the Efficiency of Oils as Mosquito Larvicides.—II. The spreading Power of Oils and Methods of increasing it
Authors: Murray David R. P. 
Published: July 2009

1. A method is described of using the Adam-Langmuir surface pressure trough for the direct measurement of the spreading power of oils against surface contamination.2. Pure higher paraffins are non-spreading and pure aromatics have only a small spreading pressure. Commercial grades of oils owe what spreading pressure they have to impurities which are only present in small quantities and can be removed.3. The spreading power of oil is greatly increased by irradiation of very thin layers of the oil. Even so, only a small fraction undergoes chemical change, the great bulk being recoverable with its original properties.
The Ecology of the Puparium of Glossina in Northern Nigeria
Authors: Nash T. A. M. 
Published: July 2009

1. The female tsetse extrudes her larva on soils ranging from fairly heavy clay to coarse sand; the presence or absence of organic matter seems to be immaterial.2. The soil temperature varies greatly in different breeding-grounds in the dry season, but little in the rains.3. The soil water content varies greatly in different breeding-grounds in the rains, but little in the dry season.4. The soil water content in some of the breeding-grounds falls so low in the dry season that there can be no doubt that the atmosphere in these soils is below saturation.5. Evaporation measured at 5 inches above ground-level varies little from site to site; bigger and important differences occur at greater heights above the ground where the screening effects of thicket become operative.6. The seasonal changes are so great at Gadau that no one breeding-ground can satisfy the female's requirements throughout the year; instead, different breeding-places are selected for different seasons.7. The cycle for G. morsitans is as follows: In the rains breeding occurs under palm fronds and logs in the open woodland. In the early dry season breeding continues in the open woodland, but shifts from the palm and log sites to the small thickets; breeding also starts in the more open parts of the forest islands. At the beginning of the very hot weather all the thickets of the open woodland are evacuated, and breeding is confined to the densest parts of the forest islands. In the early rains the movement is reversed: breeding shifts out into the open woodland, and in the heavy rains is confined to the log and palm sites.This cycle fits in closely with the cycle for the seasonal concentration and dispersal of the adult population (Nash 1937, pp. 85–90).8. The major wet season breeding-ground of G. tachinoides is unknown, but the cycle is believed to be as follows: In the early dry season breeding shifts from the log, palm, and probably from the unknown site, to the small thickets and forest islands, and becomes maximal in the cold season. Breeding now decreases in all sites, suggesting that none is really suitable—a surmise which is strengthened when tremendous breeding activity starts in the river-bed, as soon as it becomes available at the beginning of the hot season. In the early rains this site is destroyed and breeding is believed to commence in the unknown site, as it certainly does under the logs and palms.
Contribution to the Physical Ecology of Tortrix postvittana, Walk. (Lep.)
Authors: Dumbleton L. J. 
Published: July 2009

1. The thermal constant and the zero of the velocity curve have been determined for each of the pre-adult stages of Tortrix postvittana, Walk. The experimental methods are described. The thermal constant for the eggs is 153 day degrees C. and the zero of the velocity curve 4·80°C. The corresponding constants for the larvae are 469 day degrees C. and 8·05°C, and for the pupae 182 day degrees C. and 5·93°C.2. The experimentally determined constants and the mean monthly temperatures have been used to calculate the peak of the flight period of the adult moths at Huonville, Tasmania, during the 1935, 1936 and 1937 seasons. In three cases out of four the calculated dates approximate very closely to the observed dates for the peak of the flight period.3. The results of observations on the number, duration and head-widths of the larval instars are given. The majority of larvae fed on young apple leaves had four instars. A greater proportion of the larvae fed on mature apple leaves had more than four instars. The length of larval life at 25°C. is significantly longer for both male and female larvae when they are fed on mature leaves. The head width of the final instar of four-instar female larvae is significantly greater than that of the final instar of four-instar male larvae. Food quality has no apparent influence on the head width of the final instar of either male or female larvae.4. At 25°C. the length of larval life of female larvae is significantly longer than that of male larvae when both are fed on the same food ; the same tendency is exhibited at other temperatures. The separate velocity curves for male and female larvae are not significantly different in slope. The difference between velocity values for male and female larvae at the mean temperature approaches significance.5. Larval mortality increases rapidly at temperatures above 30°C. and 100 per cent, mortality occurs at 35°C. Starved larvae at low temperatures and high humidities show a tendency for the survival time to increase with the size of the larvae. Final instar larvae under these conditions can survive for two and a half months.
The Gall Midges attacking the Seed-heads of Cocksfoot,Dactylis glomerata, L
Authors: Barnes H. F. 
Published: July 2009

An account is given of four gall midges whose larvae damage the seed of cocksfoot, viz.Contarinia dactylidis(H. Lw.),Dasyneura dactylidis, Metcalfe,Sitodiplosis dactylidiswhich is described from England and Ireland in the present paper, andStenodiplosis geniculati, Reuter. The occurrence of predacious midges of the genusLestodiplosisis also noted.A short section is devoted to characters by which these midges can be distinguished.Stenodiplosis geniculatiis recorded from one English and two Irish localities on cocksfoot grass for the first time, hitherto it has always been recorded from foxtail. These midges, together with some experimentally bred on cocksfoot from foxtail parents, exhibit the typical characters of this species.A new variety,Stenodiplosis geniculativar.dactylidis, is described from cocksfoot in New Zealand.In a discussion of the host-plant specificity of gall midges attacking grass seeds, it is suggested that the present discovery ofS. geniculation cocksfoot in England and Ireland and the occurrence in New Zealand of this new variety exhibiting distinct morphological characters are two steps in the evolution of a new species.I am indebted to Miss F. M. L. Sheffield for taking the photographs used to illustrate Plate IV. They were taken to show the comparative lengths of the antennal segments and not the chaetotaxy. I am also indebted to Mr. P. S. Milne who took the photographs used to illustrate Plate V.
Melittomma insulare, Fairm. (Col. Lymexylonidae), a serious Pest of Coconut in the Seychelles
Authors: Vesey-Fitzgerald Desmond 
Published: July 2009

1.Melittomma insulareis a serious pest of coconuts in parts of Seychelles and Madagascar.2. In Seychelles the insect is only known from a few of the islands, its distributio being dependent on the original distribution of its primitive host-plants which are two species of endemic palms.3. The eggs are laid under cover in batches and hatch in eleven days. The larvae feed in galleries in the base of the trunk for an indefinite period depending on the sappiness of the wood. Pupation takes place in the enlarged end of a boring. The adult is nocturnal and short-lived.4. The damage caused depends on the age and situation of the tree which is attacked. Other things being equal trees growing on good soils are damaged least.5. Several other species of insects are associated withMelittomma, but all are of minor importance.