bluuebunny/crossref_metadata_2025 huggingface dataset:
The biological significance of the attachment of immature stages ofSimuliumto mayflies and crabs
Authors: Corbet Philip S.
Published: July 2009

It 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

An 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

An 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.
Preliminary observations on a skin-piercing blood-sucking moth (Calyptra eustrigata (Hmps.) (Lep., Noctuidae)) in Malaya
Authors: Bänziger H.
Published: July 2009

In the course of entomological investigations in Malaya between 1965 and 1967, it was found that Calyptra eustrigata (Hmps.) (Noctuidae) frequently pierces the skin of mammals to feed on blood, and in this respect differs from those Noctuids that marely imbibe blood from an open wound. Other species of Calyptra are known as fruit-piercing moths, and C. minuticornis (Gn.) which was taken in Cambodia on one occasion at the eye of a buffalo, is also one of the eye-frequenting moths, which imbibe lachrymal secretions of Ungulata, Proboscidea and occasionally of man. C. eustrigata has been observed imbibing blood after piercing the skin of buffalo, Sambar deer, Malayan tapir and nilgai antelope. Caged adults in the laboratory were observed piercing the skin of human fingers offered to them; and imbibition of blood continued for up to and hour. The proboscis, which ends in a sclerotised and strongly barbed point, can penetrate about six millimetres below the surface. The two halves of the proboscis work like two paralled saws moving alternately. While feeding is in progress, droplets of saliva exude at the base of the probiscis and run down the outside. Often some blood is regurgitated, then reabsorbed. The puncture causes itching, which can last for up to an hour, and local hardening of the tissue, which can persist for five weeks. By reason of its mode of feeding, C. eustrigata would appear to be a potential vector of disease, as the saliva and regurgitated fluids might transmit pathogenic agents.
Revisionary notes on the new world genera of Cercopid froghoppers (Homoptera: Cercopoidea)
Authors: Fennah R. G.
Published: July 2009

The Cercopidae are divided into two subfamilies, Cercopinae and Tomaspidinae, which differ from the concepts to which these names have hitherto been applied, and now include Old World and New World genera, respectively. The former Aphrophorid subfamily Neaeninae is reconstituted as a tripe of Cercopidae, and the tripe Funkhouseriini is suppressed under Tomaspidini. The genera of Tomaspidinae are keyed. and eight, Iphirhina, Aracamunia, Ocoaxo, catrimania, Urubaxia, Tunaima, Tapaiuna and Zuata, together with two subgenera, Zulia (Notozulia) and Mahanarva (Ipiranga), are described as new. One hundred and thirty-six specific names are recombined. Eight names are suppressed in synonymy, and notes are given on the genera in which these changes are made.
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).
Behavioural studies of Glossina morsitans Westw. using tantalum-182
Authors: Dean G. J. W. , Williamson B. R. , Phelps R. J.
Published: July 2009

Investigations, using tantalum-182, into the behaviour of Glossina morsitans Westw. in large field cages are described. Individual straight-line displacements occurred on average about every three hours and were generally small and erratic in direction. The perimeters of the cages tended to ‘ trap ’ an enclosed population, but flies appeared to move to the walls more quickly when they were shaded by an outer covering of hessian. Horizontal distribution and movements of flies did not appear to be associated directly with the enclosed vegetation, artificial roosting sites or host animals. Observations on vertical displacements indicated diurnal movements to and from boles of trees and changes in roosting heights. The majority of flies rested between six and ten feet above the ground, though individuals were seen from ground level to 30 ft. Few observations were done at night, but two flies were seen on the underside of leaves.
Survival and reproduction of Glossina morsitans Westw. in different types of cages exposed to variable and constant climatic conditions
Authors: Dean G. J. W. , Paget J. , Williamson B. R.
Published: July 2009

Investigations into the survival and breeding of the tsetse fly Glossina morsitans Westw. in large and small cage volumes under insectary and ambient climatic conditions in the Zambezi valley, and using oxen as host animals, are described. Under ambient conditions, flies emerging from puparia collected at Kariba, and held in the insectary, survived longer than flies emerging from puparia collected at Chirundu. Flies caught from the bush did not live as long as flies emerging from puparia held in the insectary, and generally lived longer under variable than under constant climatic conditions. The survival of ‘ wild ’ flies decreased during the hot, dry months under ambient conditions. Flies lived longer and were more reproductive in small cages than in large cages. Reproduction in small cages was higher when the flies were exposed to a variable climate instead of controlled conditions, but two colonies of ‘ wild ’ flies declined under both climatic conditions. Eeproduction was better in the small, standard cages (8 × 8 × 11 in.) than in Petana boxes, while Geigy 25’s were intermediate in this respect, but survival and mean puparial weights tended to be similar. The results show a complete failure to breed G. morsitans in large cages.
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.
A morphometric measure of phase in the desert locust, Schistocerca gregaria (Forsk.)
Authors: Symmons P. M.
Published: July 2009

This paper describes the derivation of a compound shape measure for discriminating between populations of the desert locust, Schistocerca gregaria (Forsk.). The discriminant is the first canonical variate and is based on measurements of three parameters for samples from twelve locust populations. It is argued that the first canonical variate is a measure of phase.
Susceptibility of aphids to vamidothion, a systemic insecticide, in relation to their feeding behaviour on broad beans
Authors: Lowe H. J. B.
Published: July 2009

Five species of aphid differed in susceptibility to a systemic organophosphorous insecticide injected into the stems of broad beans. The differences in susceptibility were not related to previously reported differences in feeding behaviour on this plant.
The suitability ofOctotoma scabripennisGuér. andUroplata girardiPic (Col., Chrysomelidae) for the control ofLantana(Verbenaceae) in Australia
Authors: Harley K. L. S.
Published: July 2009

The host range and aspects of the biology of Hispine beetles recorded from plants in the genusLantanais reviewed. The host specificity ofOctotoma scabripennisGuér. andUroplata girardiPic was studied in Hawaii where these insects had been imported and established for biological control of the important weedL. camara. New techniques were employed in which feeding and oviposition behaviour was studied in field and simulated-field experiments embracing a wide range of plants interplanted amongst an abundance of the Hispines' normal host. Eesults indicated that both species are restricted almost entirely toL. camara, and subsequently these insects have been imported into and established in Australia. Both insects are particularly well suited to use as biological control agents and should be extremely useful in many countries whereL. camarais a weed.
Supplement to a Monograph of the Lacciferidae (Tachardiinae) or Lac Insects (Homopt., Coccidae)
Authors: Chamberlin Joseph Conrad
Published: July 2009

Since the appearance in the pages of this Journal in 1923 of the monograph above alluded to,* there has come to the attention of the author certain nomenclatorial changes, errors, additions and criticisms which seem to justify treatment in a supplementary fashion.
The Cherry Black Fly (Myzus cerasi).
Authors: Wimshurst F. M.
Published: July 2009

Although Myzus cerasi is sometimes a serious pest of the cherry, and is therefore of economic importance in Great Britain, the life-history has never been completely worked out in the Eastern Hemisphere. A good deal of work has been done upon the species in America, and the life-history is recorded by W. A. Ross1 as it occurs on that continent.
The Natural Control of the Leaf-miner Phytomyza aconiti Hendel (Diptera) by Tachydromia minuta, Meigen (Diptera).
Authors: Whitfield F. G. Sarel
Published: July 2009

During the summer of 1924 the writer was engaged in research upon the feeding habits and the structure of the mouth-parts of Diptera. Among the families of Diptera that were studied were the Empidae, and one of the most interesting members of this family is Tachydromia minuta, Meigen, since it is among the few British Diptera, other than the Asilidae, that are entirely predacious.
The Bionomics of the White Coffee-leaf Miner, Leucoptera coffeella, Guér., in Kenya Colony. (Lepidoptera, Lyonetidae.)
Authors: Box Harold E.
Published: July 2009

The writer was able to make a field and laboratory study of Leucoptera coffeella, Guér. (white coffee-leaf miner) when serving as Entomologist in Kenya Colony.
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.
A new species belonging to the genus Anonaepestis Ragonot (Lepidoptera, Phycitinae) attacking black pepper (Piper nigrum) in West Africa
Authors: Bradley J. D.
Published: July 2009

A Phycitine species bred from larvae boring in stems of black pepper (Piper nigrum) in the Cameroons and Central African Republic is described as new and is named Anonaepestis tamsi sp.n. The species is differentiated from A. bengalella Rag., the only other known representative of the genus, and illustrations are given of the adults and female genitalia of both species and the male genitalia of A. tamsi.
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.
A note on nocturnal resting sites of Glossina morsitans Westw. in the Republic of Zambia
Authors: Robinson G. G.
Published: July 2009

With the aid of reflective patches fixed to flies, nocturnal resting sites of Glossina morsitans Westw. released in teak woodland near the Mashi River in Zambia were detected by torchlight. Within this habitat, sites on the margins of woody vegetation were chosen for the tests, so as to slow up fly dispersal and raise the chances of seeing the marked flies. Over 500 flies were marked and released, and of these 82 (16%) were subsequently seen resting, the maximum height recorded being 20 ft. above ground-level. The distribution of resting heights is shown in tables. Leaves and small twigs comprised 77 per cent, of the nocturnal resting sites. In one series of tests, the proportion of marked flies detected was considerably lower than in other tests, and an environmenal factor is thought to be the cause.
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.
Rearing pieris brassicae (L.) on semi-synthetic diets with and without cabbage
Authors: David W. A. L. , Gardiner B. O. C.
Published: July 2009

Larvae of Pieris brassicae (L.) were reared very successfully on a semi-synthetic diet containing a small amount (1·4% by wt.) of dried powdered green Brassica leaves. At 20°C., development of newly hatched larvae to the time when 50 per cent, had pupated took an average of 23 days, as compared with 21 days for larvae fed on fresh cabbage leaves. Pupal weights and emergence of adults were normal. The cabbage-leaf powder could be omitted if it was replaced by sinigrin and linseed oil, but on this diet development was prolonged by a further one or two days and the average pupal weights were lower. It seems likely that the stocks could be maintained indefinitely on either of these diets. The larvae made satisfactory growth on standard diet which had been stored at – 20°C. for two months.
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.
Insects of cultivated and wild plants, Harar Province, Ethiopia, 1960–1964
Authors: Hill Bob G.
Published: July 2009

A serially numbered list is given of plant species, both cultivated and wild, with the insect species found associated with each in Harar Province, Ethiopia, during 1960–64. In a second list, the insect species are arranged under orders and, alphabetically, under families and genera, the plant species with which they were associated being indicated by numbers referring to the first list.
Assessing the size of populations of adults of the red locust, Nomadacris septemfasciata (Serv.), in their outbreak areas by means of a helicopter
Authors: Symmons P. M.
Published: July 2009

Populations of the red locust, Nomadacris septemfasciata (Serv.), can build up to large numbers in certain of the grass plains of south-central Africa. Adult populations are always under-dispersed, and estimates of their size can be made economically only by counting the locusts flushed on line traverses of considerable length. It is necessary, in such traverses, to determine the width of the strip swept, the proportion of the locusts in it that are flushed, and the accuracy with which these are counted. Investigations into the use of a three-seat Hiller helicopter for this purpose were carried out in south-west Tanzania in 1964–65. It proved possible to cause virtually all the locusts in a strip the width of the rotor blades to rise ahead of the machine, provided it was flown at a height of about 10 ft. and at less than 10 m.p.h. and neither in the early morning nor in the late evening. A comparison of estimates of the size of the population in a 1-sq.-mile plot made by Land-Rover traverses with those made by helicopter, both when the traverse strip was marked on the ground and when it was assessed from within the helicopter, showed no evidence of systematic errors in estimating from the helicopter either the number of locusts flushed or the width of strip. Further, two observers simultaneously counting locusts rising from one strip achieved very similar results. Thus, estimation of the size of a complete outbreak-area population by means of a helicopter is clearly possible.
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.
Aircraft applications of insecticides in East Africa. XVI.—Airspray experiment with endosulfan against Glossina morsitans Westw., G. swynnertoni Aust. and G. pallidipes Aust
Authors: Hocking K. S. , Lee C. W. , Beesley J. S. S. , Matechi H. T.
Published: July 2009

An economical method of tsetse control aimed at reducing fly numbers to a low level prior to human settlement was tried in northern Tanganyika in 1964–65 in an area containing Glossina morsitans Westw., G. swynnertoni Aust. and small numbers of G. pallidipes Aust. The major central part of the infested area, about 7½ square miles, was sprayed four times at three-weekly intervals with endosulfan from an aircraft, and the remaining peripheral parts were sprayed from the ground. In the aerial applications, the volume of spray averaged 0·0121 gal./acre per application and the amount of endosulfan averaged 0·0242 Ib./acre (a total of about 1 Ib. per 10 acres for the whole operation). The results indicated that the tsetse population was probably eradicated in the part sprayed from the air. Though the ground spraying of the surrounding parts was not completely satisfactory, the tsetse population in the whole area a year later was only about ten per cent, of its original level. The cost of the air-spraying was £88 per sq. mile.
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.
Pupal development and moth emergence of the red bollworm (Diparopsis Castanea hmps.) in Malawi and Rhodesia
Authors: Tunstall J. P.
Published: July 2009

The natural moth emergence-pattern of Diparopsis castanea Hmps. from non-diapause and diapause pupae is described for Malawi and Rhodesia and related to the growth of the cotton plant. Pupal populations and mortality in the field are assessed and the location of pupae in the soil for both ridged and flat land is determined. The effect of temperature on the development of diapause pupae is investigated. Temperatures both above and below 75°F. are shown to cause inhibition of pupal development. The investigations show that it is possible to effect a major alteration in the period of moth emergence from diapause pupae by burying the pupae to a depth of eight inches and thus avoiding heat inhibition. In this way, the majorrity of moths emerge before the cotton crop is able to support an infestation. Attempts to achieve this effect with a natural field population of pupae failed and further investigation is required. Heavy grass mulches are shown to inhibit pupal development possibly throgh reduction in soil temperature and retention of soil moisture.
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.