bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the chemosterilant tepa on Glossina morsitans Westw.
Authors: Dame David A. , Ford Hugh R. 
Published: July 2009

Pupae of Glossina morsitans Westw. collected in the Zambezi valley near Kariba, Rhodesia, were brought to the laboratory, and the effects of the chemosterilant tepa were investigated by observations on the resulting adults. In the standard test, 25 pairs of adults were caged together for 28 days at 79°F. and 70 per cent, relative humidity and fed on guinea-pigs, and the survival of both sexes, the numbers of pupae and adults produced and (in some tests) the insemination rate of the parent females were recorded. With untreated flies, the insemination rate was 94 per cent, or more, averages of 28 pupae and 26 adult progeny per cage were produced, and 72 and 77 per cent, of males and females, respectively, survived for the 28 days. These results were compared with those obtained when the flies of one sex in the cage had been treated with tepa either as pupae or as adults.Injection of 1 μg. tepa into the thorax of young males produced complete sterility. Dipping the pupae in 5 per cent, tepa solution for one minute caused complete sterility of adults emerging during the first two post-treatment weeks and partial sterility of males emerging during the third week. Adults emerging from dipped pupae washed one day after treatment were fertile. Dipping pupae in solutions containing 1 or 0·5 per cent, tepa did not completely sterilise the resulting adults. Contact exposure of adult males and females of various known ages usually resulted in complete sterility (99·7%) after exposures ranging from 15 to 240 min. to deposits on glass of 10 or 50 mg./ft.2 tepa. Males exposed for 240 min. to 10 mg./ft.2 tepa retained their sterility throughout a 42-day test period and, in special tests, competed well with untreated males for the females, but their life length was reduced by 25 per cent, when unmated and by 33 per cent, when mated. Males exposed for 60 min. or less survived as well over a 42-day test period as untreated males, but those exposed for 15 min. recovered an undesirable degree of fertility. No treatment affected the ability of the male to inseminate the females. Sperm from treated males were motile and appeared normal in their behaviour in the female spermathecae. Dominant lethality induced by tepa was usually expressed during the embroyonic stages, but occasionally was delayed until the pupal stage.
Observations on the effects of γ-radiation on eggs of the desert locust,Schistocerca gregaria(Forsk.)
Authors: Hunter-Jones P. , Haskell P. T. 
Published: July 2009

It has been suggested that nuclear radiation might be used for locust control, but insufficient knowledge has hitherto been available to decide whether such a measure is feasible. In this paper, the results of some laboratory experiments on the effect of γ-radiation on eggs of the desert locust,Schistocerca gregaria(Forsk.), are described.After a single dose of γ-radiation, the resulting mortality among the eggs was correlated with the size of the dose received and the age of the egg at the time of irradiation. The dose of radiation required to kill the older eggs was 40 times greater than that required to kill young eggs; thus, a dose of 144 rads caused almost complete inviability among eggs deposited one or two days before irradiation, but a dose in excess of 5,500 rads was required to kill eggs deposited eleven days earlier. For comparison, the lethal dose of γ-radiation for humans is estimated to be 400–700 rad.When the irradiation dose was applied in three small fractions, with intervals between them, the percentage of eggs killed was less than when the same total dose was given in one exposure. This difference was presumably due to tissue recovery during the inter-radiation periods. The temperature to which the eggs were exposed during the inter-radiation periods also affected survival, recovery being greater at higher temperatures.The possibility of using γ-radiation to control locust egg-fields, the cost of the equipment needed and the hazards involved are discussed. It is concluded that control by this method not only offers no advantage in terms of cost, effectiveness or convenience as compared with conventional insecticide treatment but would be very impractical and dangerous to operators and the inhabitants, human and domestic animal, of the treated area. It is possible that other control techniques utilising radiation, such as sterile-male release or attractant traps treated with a sterilant, may be useful against certain species of locusts after further work on the development of chemical attractants has been carried out.
Multiple mating ofGlossina morsitansWestw. and its potential effect on the sterile male technique
Authors: Dame David A. , Ford Hugh R. 
Published: July 2009

Virgin females ofGlossina morsitansWestw. derived from pupae collected on the field were exposed in the laboratory to virgin sterile males and later to virgin normal males; the resulting productivity was an indication of multiple mating by females. Females inseminated once with sterile sperm and then held for 0, 24 or 96 hr. before being allowed to mate with fertile males produced about equal numbers of progeny 29–56 days later; however, subequal numbers of progeny were produced the first 28 days after the initial mating because of the relationship between the time of the second insemination and ovulation. Females given the opportunity to mate repeatedly for 96 hours with their first mates also mated again with new groups of males, but the incidence of this second mating was lower. Thus, multiple mating of females in the laboratory is established, but its frequency in nature is unkown.When groups of males were exposed to successive new groups of virgin females, the minimum mean number of females inseminated per male renged from 4.9 to 5.6. However, the later inseminations were progressively less effective, and once the complement of sperm of an individual male was depleted, fertility was not recovered. The multiple mating of male and femaleG. morsitansis not expected to affect the use of sterile males for population control.
The absorption and storage of insecticide by thein uterolarva of the tsetse flyGlossina PallidipesAust
Authors: Irving N. S. 
Published: July 2009

The increase in tolerance to topically applied chlorinated hydrocarbon insecticides shown by pregnant female tsetse flies was investigated inGlossina pallidipes. Solvent extracts of male and pregnant female flies, traeted with DDT and endosulfan labelled with carbon-14, were analysed by thin-layer chromatography and autoradiography of the developed chromatograms. No metabolites of these compounds were detected in the internal and faecal extracts. It was considered, therefore, that detoxication of absorbed insecticide was not the machanism responsible for the lower susceptibility to insecticide in the pregnant female fly. It was shown, however, by the above technique, that insecticide was absorbed by thein uterolarva.Measurement of labelled DDT absorbed by the larva was carried out by liquid scintillation counting. The results indicated that this insecticide was slowly taken up by the larva, in an amount increasing with time, and it was suggested that inert storage of toxicant in the larva is a pregnant female. This would be in addition to the effects of increase in weight and other possible physiological factors.
The bionomics and control of Argyrostagma niobe (Weym.) and Dasychira georgiana Fawc. (Lep., Lymantriidae) On black wattle in kenya
Authors: Bullock J. A. , Smith R. G. 
Published: July 2009

Argyrostagma niobe (Weym.) suddently appeared as a defoliator of wattle in 1955 in the Turbo area of Eldoret District, Kenya, and spread in this area and outbreaks also developed in two other isolated areas, at Sotik and on the Mimosa-Nandi Border. Study of the life-cycle, of which the various stages are described, revealed a number of causes of mortality of which the initially most promising for control were parasites and a predatory Pentatomid, Glypsus conspicuus (Westw.). None of these, however, increased greatly above their first recorded level of incidence and the population of A. niobe was eventually controlled by a naturally-occurring nuclear polyhedrosis. This disease was found to be transmissible in the laboratory by allowing larvae to feed on foliage sprayed with suspensions of polyhedŕa whilst an indication that this could also be done in the field was obtained in one experiment.Chamical control presented a number of difficulties, the chief arising from insufficient dispersion of the spray through the canopy of tall trees and the failure of small droplets finally adopted consisted of an application of endrin applied at a rate of 2–4 oz. active ingredient per acre in 2 gall. diesolene. This was satisfactory when applied to yonug trees through a Micron sprayer, and to trees of all heights by aerial boom sprayers. This mathod of control is only suitable where complete elimination of a population is necessary, such as in a new outbreak area, as the costs are too high to permit frequent applications.Dasychira georgiana Fawc. was recorded in small numbers at about the same time that A. niobe was first recorded, but the population did not build up to serious proportions. Its life cycle, of which the various stages are described, was broadly similar to that of A. niobe but natural agents of control, chiefly the pupal parasite Compsophorus fumosus (Morl.) (Ichneumonidae), were usually effective in keeping the population in check. The reason for the success of this parasite, as compared with those of A. niobe, is not known. The larvae were successfully controlled with the same endrin spray as was used for A. niobe.
Seasonal population changes in cocoa capsids (Hemiptera, Miridae) in Ghana
Authors: Gibbs D. G. , Pickett A. D. , Leston Dennis 
Published: July 2009

Pupulations of the West African cocoa capsidsDistantiella theobroma(Dist.) andSahlbergella singularisHagl. were sampled in 1966–67 by several methods: fast knockdown over sheets with pyrethrum, mercury-vapour light-trap, direct counts in a small artificially established area of high population, and observations of presence or absence in randomly selected inspection squares.A population build-up in mature cocoa accompanies and probably directly depends on development of the main crop from July or August to October. When pods become scarce after harvesting there is inS. singilarisa period of dispersal in which the species becomes more widespread as feeding is transferred to vegetative tissues, and inD. theobromaa more local change of feeding sites.Subsequent events vary greatly between areas and between years. It is suggested that the extent to which capsids are able to utilise vegetative tissues varies and depends on nutritional changes in the external parenchymatous tissues from which their food is obtained.Low humidities during spells of harmattan in January and February almost certainly kill larvae in exposed situations, but feeding conditions following such periods may be particularly favourable to capsids as large rapid population increases can occur locally. The factors involved are obscure but may be related to processes of regeneration stimulated by leaf loss and other damage in dry conditions.The densities and seasonal patterns found are discussed in relation to results of previous workers and some implications for control briefly considered.
Chemical control of an organophosphorus-and carbamate-resistant strain of Boophilus microplus (Can.) from Queensland
Authors: Roulston W. J. , Stone B. F. , Wilson J. T. , White L. I. 
Published: July 2009

Recognition in 1963 in central Queensland of the Ridgelands strain of Boophilus microplus (Can.), resistant in varying degrees in laboratory tests to all acaricides commercially available in Queensland, Australia, led to spraying trials on cattle with these acaricides to assess their effect on the resistant strain. Dosage mortality tests on larvae exposed in acaricide-impregnated filter papers, indicated the following levels of resistance, carbary 13×, carbophenothion 17×, coumaphos 1.6×, diazinon 19×, dioxathion 7.2× and ethion 2.7×.Stalled cattle infested with either susceptible Yeerongpilly or resistant Ridgelands ticks were sprayed with the recommended concentration of commercially formulated acaricide. Efficiency of treatment was determined by comparing the number of ticks falling from sprayed and unsprayed cattle. Coumaphos (0.025%) and ethion (0.075%) produced efficient control of the resistant strain, but carbophenothion (0.086%), diazinon (0.05%) and dioxathion (0.075%) allowed considerable numbers of the resistant strain of ticks to survive. Carbaryl (0.3%) as a melt-type formulation gave inconsistent results and possible reasons are discussed. Poor control of the resistant strain was largely due to failure to kill the nymph stage.There was general correspondence between the resisdence level determined in laboratory tests and the degree of control achieved in spraying trials. However, the reletively small difference between resistence levels of 2–3× (coumaphos and ethion) and 7× (dioxathion) was critical in the practical control of resistant ticks on cattle.The following chemicals gave excellent control of the Ridgelands strain in spraying trials on stalled cattle: bromophos (0.15%), bromophos ethyl (0.1%), chlorfenvinphos (0.06%), chlorxylam (0.5%), Ciodrin (0.1%) Dursban (0.025%), fenchlorphos (0.2%), GS13002 (0.05%), Imidan (0.075%), methidathion (0.05%) and SD8448 (0.025%). Malathion (0.5%), prothidathion (0.075%), macarbam (0.075%) and RD12308 (0.2%) controlled the Yeerongpilly but not the Ridgelands strain. Arsenic (0.2%) produced about equal mortality in both strains, but was clearly a less efficient acaricide than organophosphorus chemicals.
Heliothis armigera (Hb.) (Noctuidae) in Western Tanganyika. I.—Biology, with special reference to the pupal stage
Authors: Reed W. 
Published: July 2009

In laboratory studies of Heliothis armigera (Hb.) in Western Tanganyika, where it may attack cotton severely, pairs of newly emerged adults, derived from sixth-instar larvae collected in the field and allowed to pupate in the laboratory, were confined separately and provided with sucrose solution. The mean number of eggs laid per female fell from 1,226 in March-May to 198 in June—July 1962. Peak egg laying occurred in the fifth to eighth nights after emergence. In April, the mean length of life of adults of either sex was about 11 days and the maximum one month. The mean incubation period of 1,436 eggs laid in March was 2·78 days, and 66 per cent. of them hatched. The mean period from hatching to pupation of 42 larvae reared on cotton squares in April was 21·1 days; each passed through six instars and required three squares in the first 14 days and a further 10 thereafter; only 22 per cent. of the dry weight of the squares was consumed and of this only nine per cent. was converted to pupal dry weight.Pupation occurs in the soil. The mean pupal period of males increased from 16 days in March to 18 in July, and their pupal weights fell from about 0·27 to 0·23 mg. over the same period, although at any given time pupal period was positively correlated with pupal weight. Female pupae were lighter than male pupae and had a shorter pupal period.From March to July, a small but progressively increasing proportion of the pupae formed entered diapause; the proportion averaged less than four per cent. in June to July 1962–64. The pupal period ranged from 30 to 171 days, being less in later-formed pupae, so that a general emergence occurred in September–late October.
Some effects of resistance to organophosphorus insecticides in Myzus persicae (Sulz.) on the transmission of beet yellowing viruses
Authors: Russell G. E. 
Published: July 2009

A population of Myzus persicae (Sulz.) that apparently showed resistance to organophosphorus insecticides was found on plants growing in glasshouses at the Plant Breeding Institute, Cambridge, in 1963. Experiments were conducted to compare the resistance to dimethoate and demeton-methyl of this population with that of another population, which had never been treated with insecticides. The resistant aphids were killed much more slowly than were susceptible aphids on plants sprayed with organophosphates, and they were able to transmit beet yellows virus (BYV) and beet mild yellowing virus (BMYV) to the treated plants. Under similar conditions, susceptible aphids were able to transmit BYV, a semi-persistent virus, but less efficiently than the resistant aphids, and were not able to transmit BMYV, a persistent virus, at all.It is not known how common these organophosphorus-resistant populations of M. persicae are, at present, in the field in Britain. Under normal field conditions, control of such resistant aphids would be difficult, and virus yellows might, in consequence, become widespread even in crops that had been treated with organophosphorus chemicals.
Ecological significance and practical implications of behaviour patterns determining the spatial structure of insect populations in stored grain
Authors: Surtees Gordon 
Published: July 2009

The influence of population density, temperature, humidity and other environmental factors on the individual behaviour, aggregation in restricted parts of the habitat (accumulation) and spatial structure of the population (dispersion) of five species of beetles found in stored grain in Britain was the subject of laboratory studies by the author in 1959–65. In this paper, the results of these studies are drawn together, compared with field observations, and discussed in relation to behavioural mechanisms, ecology and control. The five species comprised Oryzaephilus surinamensis (L.), Tribolium castaneum (Hbst.).Cryptolestes ferrugineus (Steph.), Rhyzopertha dominica (F.) and Sitophilus granarius (L.). A basic plan of behaviour is considered to underlie the observed dispersion of these pests in grain, which may be summarised as follows: random movement of individuals causes disturbance within the population and leads to dispersal; accumulation occurs where individual movement is most restricted in response to environmental factors and where disturbance is consequently at a minimum.The dispersion of O. surinamensis is almost entirely determined by kinesis mechanisms, and accumulation takes place in the warmest and dampest parts of a grain bulk. The dispersion of T. castaneum is determined to a lesser extent by kinesis mechanisms; accumulations take place in the drier parts of a bulk and at places where the temperature is about 25°C., but also in regions of damp grain if this is mouldy. The dispersion of C. jerrugineus is mainly determined by behaviour relating to the requirements of oviposition and feeding, which is superimposed on the basic plan. R. dominica accumulates in the driest parts of a grain bulk. The dispersion of S. granarius is largely determined by individual thigmotactic behaviour, so that accumulations are typically at the periphery of the grain bulk.The ways in which a knowledge of the underlying causes of dispersion and accumulation aid in the detection and control of the pests and point to the optimum storage conditions are described.
Acaricide trials against Rhipicephalus appendiculatus Neum., Amblyomma variegatum (F.) and Boophilus decoloratus (Koch) (Ixodidae) on cattle in Uganda
Authors: Matthysse John G. , Colbo Murray H. , Kamya E. P. 
Published: July 2009

Field trials were conducted to compare toxicity and residual activity on cattle of 18 acaricides against Rhipicephalus appendiculatus Neum., Amblyomma variegatum (F.), and Boophilus decoloratus (Koch). Ticks were counted one, four and seven days after the cattle were sprayed. Each of the seven experiments involved three sprayings at seven- to eight-day intervals.Toxaphene at 0.25 per cent., included as a standard, was relatively slow acting compared to organophosphorous and carbamate acaricides, but was equal to or better than most of the new acaricides in residual activity and over-all effectiveness. Carbaryl, Mopham and toxaphene were tested at the highest concertration, 0.5 per cent., and found to have the maximum over-all effectiveness, including maximum residual activity. Nevertheless, even these treatments did not protexct cattle against tick attachment and engorgement for as long as seven days.All acaricides tested were very effective against B. decoloratus and A. variegatum, but none completely prevented attachment of R. appendiculatus foe as long as four days, even though all were very toxic to this tick. The smallest number (1.8 per beast) of R. appendiculatus attaching in four days occurred on the cattle sprayed with 0.5 per cent. carbaryl, but by seven days after spraying there were many ticks attached and some were already partially engorged. The inference is that none of the compounds tested gave promise of prevention of tick-borne disease transmission when used on a seven-day schedule. No inference is made concerning tick-borne disease control by reduction of tick numbers on the pasture land.Mortality among ticks on the cattle one day after treatment was greatest for 0.1 per cent. coumaphos, 0.25 per cent. Prolate, 0.05 per cent. Bayer 9053, 0.2 per cent. Geigy GS 13006, 0.2 per cent. and 0.5 percent. carbaryl, 0.1 per cent dioxathion, 0.05 per cent. Bayer 9037, 0.1 per cent. prothidathion, 0.1 per cent. Dursban, 0.2 per cent. and 0.5 per cent. Mobam, 0.025 per cent. and 0.05 percent. chlorfenvinphos, 0.2 per cent. fenitrithion and 0.1 per cent. ethion. Mortalities of 83.1 per cent. to 88.5 per cent. were given by 0.05 per cent. diazinon, 0.1 per cent. bromophos-ethyl, 0.025 per cent. Dursban, and 0.5 per cent. toxaphene. Mortality below 74 per cent. was caused by 0.25 per cent. toxaphene, 0.2 per cent. bromocyelen, and 0.1 per cent. carbophenothion.
Distribution and trypanosome infection rates ofGlossina morsitans submorsitansNewst. along a trade cattle route in south-western Nigeria
Authors: Baldry D. A. T. 
Published: July 2009

The distribution and trypanosome infection rates ofGlossina morsitans submorsitansNewst. were studied during the wet season of 1967 along 75 miles of the main trade cattle route which passes through the savannah country between Ilorin and Oyo in south-western Nigeria.G.m. submorsitanswas found inhabiting open woodland, grassland, farmland and the environs of towns associated with the cattle route. In comparison with the types of habitat this species occupies in its zone of wide distribution in northern Nigeria, those habitats studied were considered atypical. It is suggested that the presence ofG.m. submorsitansin the area investigated had resulted from a southward population advance over the last 50 years and this hypothesis is discussed in relation to existing knowledge ofG.m. submorsitansadvances.The trypanosome infection rates of 61.6 and 76.6 per cent, found in 364 examples ofG.m. submorsitansdissected are much higher than previously recorded for any of the subspecies ofG. morsitansWestw. A steady southward increase in the trypanosome infection rates ofG.m. submorsitanswas demonstrated for populations inhabiting 200 miles of cattle route. Trypanosome infections inG.m. submorsitansare attributed toTrypanosoma vivaxandT. congolense, and the absence ofbrucei-group infections is discussed in relation to the incidence ofT. bruceiinfections in trade cattle and limitations of the technique used for demonstrating infections in tsetse flies.It is stressed that epizootiological aspects of the present findings cannot be clarified until reliable data on trypanosome infections of trade cattle in the area studied are available.