bluuebunny/crossref_metadata_2025_split huggingface dataset:
The histochemistry of the cholinesterases in the central nervous system of susceptible and resistant strains of the house-fly,Musca domesticaL., in relation to diazinon poisoning
Authors: Molloy Frances M. 
Published: July 2009

SummaryThe distribution of cholinesterases hydrolysing acetyl- and butyrylthiocholine in the brain and thoracic ganglion ofMusca domesticaL. was examined histochemically in untreated flies, and in flies poisoned with diazinon (O,O-diethyl 0–2–isopropyl–4–methyl–6–pyrimidinyl phosphorothioate) of both susceptible and resistant strains.The inhibition of cholinesterase after poisoning was, to a greater or lesser extent, confined to the peripheral region of the ganglia, and to other specific areas such as the suboesophageal ganglion and lamina ganglionaris. The extent of inhibition increased with increasing doses of poison, and increasing time after treatment. The degree of inhibition could be broadly correlated with the condition of the fly; badly affected or moribund flies having less active cholinesterase than living and unaffected flies. Together with these areas of more or less complete inhibition were other areas, especially in the neuropile or synaptic regions, in which there remained large amounts of active enzyme. Active enzyme was still present in these areas 24 hours after apparent death of the fly. Total inhibition of cholinesterase throughout the central nervous system was rarely seen, even after very high doses of diazinon causing over 99 per cent. kill.Inhibition did not occur in the ganglia of living flies of a diazinon-resistant strain after a dose which caused inhibition and death in the normal susceptible strain. With 25 times this dose, causing approximately 99 per cent, kill in the resistant flies, cholinesterase was inhibited in them also, although to a somewhat lesser extent than in the susceptible flies given a comparable lethal dose.The data provided strong evidence that if death is caused by inhibition of cholinesterase of the nervous system it is due to local inhibition and not to generalised inhibition.
The biological significance of the attachment of immature stages ofSimuliumto mayflies and crabs
Authors: Corbet Philip S. 
Published: July 2009

SummaryIt is suggested that the attachment of the immature stages of certain species ofSimulidaeto mayfly larvae and to crabs is primarily an adaptation whereby the immobileSimuliumpupa can obtain protection against disorientation with respect to the current, and against damage, in an environment where available inorganic substrata are liable to be displaced by violent water movement.The principal evidence for this is that these associations typically occur in fast-flowing streams or rivers, and that the attached stages ofSimuliuminclude a disproportionately high number of pupae and large larvae. Any direct benefit theSimuliumlarvae themselves may derive from the association is regarded as a secondary feature of it.Certain responses to physical factors, which might be expected insimuliumlarvae achieving successful attachment, are briefly discussed.
Observations on the habits of mosquitos of Plateau Province, Northern Nigeria, with particular reference to Aëdes (Stegomyia) vittatus (Bigot)
Authors: Boorman J. P. T. 
Published: July 2009

SummaryAn account is given of a survey of the mosquitos of the Jos area of Northern Nigeria, during May–June 1960, particular attention being given to those species likely to be concerned with the transmission of arthropod-borne viruses. The area concerned is in the savannah belt at an altitude of about 4,000 ft., with numerous rocky outcrops. The dry season is fairly severe, and extends from about October to May; during this time, drinking water for the villages is obtained from deep wells. At the time of the survey, that is, at the beginning of the rainy season, the most abundant species were Culex univittatus Theo., Aëdes ingrami Edw., A. aegypti (L.), A. africanus (Theo.), A. luteocephalus (Newst.) and A. vittatus (Big.). The biting cycles of these species are illustrated.A survey was carried out of the breeding habits of A. vittatus in rock holes; those most favoured were about a foot across and six to nine inches deep, and appeared to be of human origin. Larvae appeared rapidly in the holes after the first rains, and predators, particularly dragonfly nymphs and tadpoles, were common in the larger rock holes. Under natural conditions, the duration of the life-cycle was about five days. The survival of the early stages under adverse conditions was investigated in simple laboratory experiments. At normal temperatures, the pupae did not survive desiccation for six hours, and, though the resistance of larvae to drying was not tested fully, it is considered that they are probably no more resistant than are pupae. Eggs survived desiccation for 10 but not for 18 weeks. Water temperature in exposed rock holes was not a factor limiting development, but the temperature of the exposed surface of dry rock holes was such that it appeared unlikely that eggs in these exposed situations would be able to survive the dry season. It was suggested that there may be collections of water in sheltered tree holes or rock holes which support a small but more or less continuously breeding population; this, combined with the ability of the eggs of A. vittatus to withstand desiccation for at least ten weeks at normal temperatures would enable the species to survive the relatively prolonged dry season.
Admixture of malathion and lindane with bagged maize
Authors: Graham W. M. , Kockum S. P. L. 
Published: July 2009

SummaryAn experiment was done in Kenya to test several formulations of lindane and malathion dusts as protectants of bagged maize, with which they were mixed, against reinfestation (post-fumigation infestation) by store pests. The experiment was in the form of a 9 x 9 Latin square employing 162 bags. Sampling initially and after 4 and 5¼ months gave data on bag weight-losses, dust present per bag, numbers of adults of Tribolium castaneum (Hbst.), Oryzaephilus surinamensis (L.), Cadra cautella (Wlk.) and Sitophilus oryzae (L.), and moisture-content changes.The dust weights (which were expected to be the most reliable measure of treatment efficacy) showed that there was very little difference between malathion admixed at 8, 4 and 2 parts per million. The other six treatments were far less satisfactory and all were significantly different from one another, with the following order of values: lindane at 6, 3 and 1·5 p.p.m., diatomite, kaolin and control. All the other data generally supported these results.The extreme importance in this experiment of cross-infestation from nearby stacks has been shown in the analysis and has been illustrated by plotting numbers of T. castaneum against dust-weight data. Interpretation of this curve has lent support to work with lindane and malathion published by E. A. Parkin in 1960.The results emphasise the significance of the contribution of grain and mould metabolism to the total bag weight-losses. Some estimates are made of the savings relevant to the admixture of malathion.
A laboratory study of competition betweenTribolium castaneum(Hbst.) (Coleoptera, Tenebrionidae) and three moth species
Authors: Adeyemi S. A. O. 
Published: July 2009

Laboratory studies were undertaken to find out if the increased degree of infestation by certain moth species,Cadra cautella(Wlk.),plodia interpunctella(Hb.) andCorcyra cephalonica(Stnt.) following the chemical control of beetles includingTribolium castaneum(Hbst.) in stacks of groundnut (Arachis) in Nigeria could be due to relaxation of inter-specific competition.All test insects were reared and studied at a constant temperature of 25.5°C. and 70 per cent. ralative humidity. All experiments were conducted on shelled nuts (or germs of nuts) in specimen tubes, crystallising dishes or jam jars. The survival and development of the immature stages of the moth species was studied and the numbers of eggs laid by the adults recorded in the presence of adults ofT. castaneum;the reciprocal effects of moth larvae onT. castaneumwere also briefly studied.The most important harmful effects ofT. castaneumwere on copulating moths and on moth eggs. Adults were frequently disturbed and sometimes killed or, if they survived, laid fewer eggs; eggs were also eaten, especially those laid loose in the medium. Adults ofT. castaneumalso attacked and killed moth larvae and pupae, but this was considered to be of minor importance. The silk produced by moth larvae was inimical to larvae ofT. castaneum, but the effect on the population ofT. castaneumwas probably offset by the beneficial effect of moth cocoons, which provide shelter for larvae ofT. castaneumfrom cannibalism.It is conculaded that as a result of competition for food and/or space betweenT. castaneumand the moth species the moth populations are likely to be exterminated despite their apparently higher intrisic rate of increase.
The biting habits of some Jamaican Culicoides I. C. barbosai Wirth & Blanton
Authors: Kettle D. S. , Linley J. R. 
Published: July 2009

Field studies on the biting habits of Culicoides barbosai Wirth & Blanton were made near Montego Bay, Jamaica, during 1959 and 1960. Females of C. barbosai were collected in sufficient numbers for analysis in. seven experiments, six from Florida beach and one from Beading. Four positions were marked out on each site. Begular meteorological observations were made in the middle of the catching positions. An experiment consisted of four trials held on different days, each trial being composed of four collecting periods of 15 min. separated by 5-min. intervals. In each period four individuals collected, two exposing an arm each and two a leg. Individuals collected in a different position in each period of a trial.Catches were logarithmically transformed for analysis and tests of significance. The experiments were designed to provide correction factors for limbs, positions on Florida beach, and collectors, for use in other experiments. Correction factors are given as logarithms for application to transformed catches.More C. barbosai were collected from arms than legs, and catches in position IV were significantly higher than those in positions I, II and III. Five collectors (C, D, K, L and S) were compared. The ratio between leg/arm catches from D, who collected in only two experiments, was significantly different from those of C, L and S. The differences between the catches of C, K and L were insignificant, but all three caught significantly more than S. The catches from L were smaller after sea bathing and, compared to C and S, L’s catches increased significantly immediately after sunset. For this reason and to avoid inhibiting winds, quantitative studies on females of C. barbosai are best conducted in the early morning (dawn + 40 min.).The experimental errors (residual variances) were homogeneous with probabilities of 0.1 (C. barbosai—7 experiments) and 0.4 (C. furens (Poey)—8 experiments).
Assessment of the suitability of Plagiohammus spinipennis (Thoms.) (Col., Cerambycidae) as an agent for control of weeds of the genus Lantana (Verbenaceae). II. Host specificity
Authors: Harley K. L. S. , Kunimoto R. K. 
Published: July 2009

Results are presented of a study of the host specificity of Plagiohammus spinipennis (Thorns.) under conditions that emphasised the behaviour of the insect in the field in the presence of an abundance of its host-plant, Lantana cantata. The results of this and previous studies are compared.The adult beetles fed on various test plants but had little or no deleterious effect. Oviposition was restricted to the insect’s normal host, L. camara, and to Cordia ambigua, G. grandiflora, G. curassavica, Lippia umbellata, Lippia sp. (? miocephala), Tectona grandis and Vernonia deppeana. Of these, only T. grandis is of commercial importance. Larvae were unable to complete their development on this plant and died after feeding briefly. Development by larvae of P. spinipennis was restricted to a small group of mostly related, unimportant plant species as well as the serious weed L. camara.P. spinipennis thus shows a high degree of host specificity, and was therefore liberated for control of Lantana camara in Australia in 1967.
Some aspects of insecticidal and biological control of the woolly apple aphid, Eriosoma lanigerum (Hsm.) in Rhodesia
Authors: Carnegie A. J. M. 
Published: July 2009

In insecticide trials in 1962–63 in Rhodesia against woolly apple aphid, Eriosoma lanigerum (Hsm.), no appreciable control was achieved by applying ½ fluid oz. of a 40 per cent, emulsifiable concentrate of dimethoate per tree at 2- to 3-week intervals for 16 weeks in any of the following ways: painted directly on the lower trunk; absorbed in a cotton-wool band applied to the trunk, after being diluted 1:3 in water; applied to a furrow around the stem after being diluted in four gallons of water; injected into the soil with a nematicide injector after being diluted 1:4 in water.A foliage spray of DDT (0·195% active ingredient) had a gradual controlling effect on the aphid and caused no upsurge such as might have occurred had the parasitic activities of Aphelinus mali (Hald.) been suppressed.Activity of the ant Pheidole megacephala (F.) was immediately halted on trees sprayed with DDT and was suppressed on trees the trunks of which were painted with dimethoate and on those banded with a dimethoate-soaked barrier.Over a fourteen-month period, the numbers of living aphid colonies fluctuated before decreasing at the same time as the activity of A. mali intensified.
A verandah-trap hut for studying the house-frequenting habits of mosquitos and for assessing insecticides. II.—The effect of dichlorvos (DDVP) on egress and mortality of Anopheles gambiae Giles and Mansonia uniformis (Theo.) entering naturally
Authors: Smith Alec 
Published: July 2009

Assessment of the effects of dichlorvos (DDVP), released from a Ciba XI dispenser, on females of Anopheles gambiae Giles and Mansonia uniformis (Theo.) entering a verandah-trap hut in the Umbugwe area of Tanzania was made over a period of two months in 1964. Of the numbers of A. gambiae that entered one treated and one untreated hut, 27 per cent, of those entering the hut treated with dichlorvos and 48 per cent, of those entering the untreated hut left again. Of the numbers leaving each hut, 38 per cent, left through the eaves of the treated hut as compared with 9 per cent, in the untreated one. In the case of M. uniformis, 88 per cent, of those entering the treated hut and 94 per cent, of those entering the untreated hut left again. Of the numbers leaving each hut, 59 per cent, left through the eaves of the treated hut as compared with 61 per cent, in the untreated one.Over-all mortalities were 56 per cent, for A. gambiae and 34 per cent, for M. uniformis when the eave-egress fraction from the treated hut was taken into account, compared with 62 per cent, for A. gambiae and 43 per cent, for M. uniformis when the eave-egress fraction was ignored.The results of bioassays and of chemical analyses showed that the problem of mortality from fumigation in situ was considerably less in verandah traps than indoors or in window traps fitted with funnels of cotton netting.
Mutations in the sheep blowfly Lucilia cuprina (Wied.). II.—Studies on genes for black pupa and dieldrin-resistance
Authors: Shanahan G. J. 
Published: July 2009

The inheritance of black pupa in Lucilia cuprina (Wied.) was investigated by means of a series of back-crosses through five generations. Since an approximate 1:1 ratio of reddish brown to black pupae was observed throughout, it is concluded that the character black pupa is due to a single recessive gene (bp).A test for the existence of a linkage group containing genes for black pupa and dieldrin-susceptibility was then made. The exposure of females from reddish brown and black pupae derived from back-crosses to discriminating levels of dieldrin, and the pattern of mortality observed with scalar concentrations of dieldrin, indicated that genes for black pupa (bp) and dieldrin-susceptibility (rdi) are on different chromosomes.
Seasonal abundance and diurnal variations in activity of some Stomoxys and Tabanidae in Uganda
Authors: Harley J. M. B. 
Published: July 2009

The results are described of 202 24-hr, catches of Stomoxys and Tabanids on cattle at Lugala on the north-eastern shore of Lake Victoria, and also of six 24-hr, catches at Sukulu, 33 miles from Lugala, all of which were made in 1961–63.Species of Tabanus and Ancala were more abundant in open grassland than inside the edge of the lake-shore forest. Stomoxys nigra, Macq. and S. Calcitrans (L.) were equally numerous in both situations, whereas S. omega Newst. was most abundant inside the forest edge.Many species were caught during all months of the year. In both catching areas, there were seasonal rises in numbers of nearly all species between May and August and again in November or December, that is, towards the end of the rains and early in the dry seasons. At one of the two areas there was also a large increase in catch of a few species in April, in the middle of the main wet season.Diurnal activity of Tabanus and Ancala was greatest near the middle of the day, the exact timing of the peak varying with season. Four species of Haematopota exhibited morning and evening peaks with lower activity at midday, and a rather rare fifth species was apparently more active in the middle of the day. Three species of Stomoxys were also most active in the morning and late evening, but peak activity of a fourth species, S. calcitrans, occurred shortly after midday. Activity during the night was rare.
The biology and control of termites damaging field crops in Tanganyika
Authors: Bigger M. 
Published: July 2009

Many crops in southern Tanganyika are attacked by termites, especially those grown in the miombo woodland (Brachystegia-Pseudoberlinia), which covers much of the southern and western parts of the country. The termites chiefly concerned are Microtermes albopartitus (Sjöst.), M. redenianus (Sjöst.), Ancistrotermes latinotus (Hlmgr.) and Allodontermes tenax (Silv.). A pit dug to investigate their nest systems showed that M. albopartitus was the most numerous, 425 occupied cells being recovered from an area 50 × 24 ft. excavated to a depth of 6 ft. Cells of the other species included 166 of M. redenianus, 54 of Ancistrotermes latinotus and 49 of Allodontermes tenax. The cells of Ancistrotermes latinotus were aggregated into small clusters connected by long runways; those of the other species were more or less randomly scattered. The greatest concentration of cells of all species was within the top 2 ft. of the soil, but a number of cells were found at greater depths and it is certain that 6 ft. is not the maximum nesting depth. Descriptions of the nest systems and fungus combs are given.Observations at Nachingwea in 1959–63 showed that loss of maize stands from termite attack averaged 27 per cent, over the five years, and that of soya 33 per cent. The damage was often great on individual plots, as much as 90 per cent, being recorded from one plot of maize. Plant-population counts over three growing seasons showed that maize is lost mainly towards the end of the season, whereas soya may be attacked any time after planting, increased losses occurring during dry spells and at the end of the season.Control was achieved by the use of aldrin or dieldrin applied as dusts to the soil before planting or used in seed dressings. It was found in a series of field trials that good control of termites was afforded by aldrin worked into the soil along the planting ridges at a rate of 1 lb. active ingredient per acre, but that in practice ½ lb. per acre gave nearly as good results when measured by yields. In spite of the considerable losses, it was considered uneconomic to use aldrin to protect soya from termite attack, but the increased yields of 200–400 lb. maize per acre justified the expenditure on insecticide. The aldrin dust protected both crops for at least one further year after application, the effects on yield being of the same order as before.A seed dressing of 75 per cent, dieldrin gave excellent control and was considerably cheaper than soil application of aldrin. The cost was only a few shillings an acre when the dressing was used at the rate of 0·1 oz. per 1 lb. seed, and the effect was to raise yields of maize by 330–500 lb. and of soya by 110–180 lb. per acre.Trenches were dug to investigate the effects of soil treatment with aldrin on the nest systems of the termites. There was little effect on cell density eight months after application, but after 20 months there were signs of a reduction, especially in the top 9 in. of the soil.
The time of flight and the relative importance of Myzus persicae (Sulz.) and Aphis fabae Scop. in relation to the incidence of beet yellows as shown by trap catches at Rothamsted and Broom's Barn
Authors: Heathcote G. D. 
Published: July 2009

Sticky traps were operated over sugar-beet crops at Rothamsted Experimental Station (Hertfordshire), Broom's Barn Experimental Station (Suffolk) and elsewhere for five years to gain information about the flight of the aphids that transmit beet yellowing viruses and to aid in the spray warning scheme for sugar-beet growers.Numbers of Myzus persicae (Sulz.), Aphis fabae Scop, and of all aphids caught per week are given. Records of aphids trapped at Rothamsted over a period of 23 years have been published; but no repeating pattern of aphid abundance from year to year has been detected. M. persicae flew early in 1960 and 1961, when beet viruses spread extensively, whereas in 1962, 1963 and 1964, when alates of this species did not fly early but were trapped in relatively larger numbers later in the year, yellows spread much less. Large numbers of A. fabae flew in 1963, but beet viruses spread little.