bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of site and sampling method on the size and composition of catches of tsetse flies (Glossina) and Tabanidae (Diptera)
Authors: Saunders D. S. 
Published: July 2009

Two experiments on factors affecting the size and composition of catches of tsetse flies, principally Glossina pallidipes Aust., were carried out in 1963 in South Busoga, Uganda. Eight attractants were distributed between eight sites on eight successive days in a Latin square design for each experiment. The attractants comprised two black Zebu oxen and Morris traps covered with ordinary hessian (brown traps) or with hessian dyed black (black traps). Three of the sites were on the edge of a large thicket, two were close to isolated clumps of thicket in the midst of grassland and three were in the open grassland itself. Catching took place for 12 hours each day. The total numbers and sex ratio were recorded for each catch, and also, from dissections, the age composition and pregnancy states of the female portion of the catch. Examples of G. brevipalpis Newst., G. palpalis fuscipes Newst. and of 13 species of Tabanidae were also caught, but in smaller numbers, and were recorded in less detail.Catches of G. pallidipes at sites close to the thicket edge were considerably greater than at sites away from the thicket, but, apart from an increased proportion of nulliparous females at the clump and grass sites, the composition of the female sample was unaffected by the type of site. The bait-oxen caught larger samples than the traps, but a smaller proportion of females, and these contained a higher proportion of young flies and of flies carrying an egg in the uterus. In comparison with brown traps, black traps caught smaller numbers of G. pallidipes, and a smaller portion of females, but a larger proportion of these were nulliparous. Although the two oxen had been selected for similarity of size and colour, they differed in the samples they attracted: one of them consistently attracted a larger sample of all the common species and, in the second experiment, a larger proportion of females in the samples of G. pallidipes. Most examples of G. palpalis fuscipes were caught at the three edge sites, and all but one example of G. brevipalpis were caught on the bait-oxen.All examples of the 13 species of Tabanidae caught on the oxen or in the traps were females. Apart from Tabanus par Wlk. they were poorly represented in the trap-catches, and there was no obvious effect of site upon the size of the samples.
Inheritance of dieldrin-resistance in Cimex lectularius L. and Pediculus h. humanus L
Authors: Guneidy A. M. , Busvine J. R. 
Published: July 2009

The mode of inheritance of dieldrin-resistance in Cimex lectularius L. and Pediculus h. humanus L. was investigated. The method involved the determination of dosage/mortality regression lines by exposing batches of insects to a range of dieldrin concentrations. Reciprocal crosses were made between normal (N) and resistant (R) strains of each insect, and the F1 and F2 progeny were examined for susceptibility levels over a wide range of concentrations of dieldrin. Back-crosses were made from the F1 generation to N and R strains, and the progeny were examined in the same way. In some cases, further back-crosses were made after elimination of susceptible individuals from the progeny of the first back-cross.All the results with C. lectularius were consistent with monofactorial inheritance of dieldrin-resistance through a gene of intermediate dominance. With P. h. humanus, the results were complicated by an apparent maternal effect which caused the F1 and F2 generations from a N ♀ × R ♂ cross to be less resistant than those from a R ♀ × N ♂ cross. In general, however, the results indicated genetic segregation consistent with the same type of monofactorial inheritance as that found in C. lectularius.
Dieldrin-resistance in a strain of Aedes aegypti (L.) from Puerto Rico
Authors: Guneidy A. M. 
Published: July 2009

The cross-resistance characteristics of a dieldrin-resistant strain of Aedes aegypti (L.) from Puerto Rico were investigated by comparative tests on the adults of this and of a normal strain, using various insecticides. A resistance spectrum typical of that associated with resistance to BHC/dieldrin in other insects was revealed, characterised by slight or negligible cross-resistance to DDT, malathion and diazinon.The mode of inheritance of dieldrin-resistance was studied by determining resistance levels in the progeny of direct crosses of the resistant and normal strains and of back-crosses. The F1 generation of the direct cross was of intermediate resistance, and the F1 generation showed 1:2:1 segregation into normal, intermediate and resistant individuals. Both back-crosses showed 1:1 segregation into susceptible and intermediate individuals when the back-cross was to the susceptible parent, or into intermediate and resistant individuals when it was to the resistant parent, and these results were confirmed when one genotype was eliminated and the back-cross was repeated. These results indicate monofactorial inheritance of an autosomal gene with intermediate dominance, which is typical of the BHC/dieldrin type of resistance.
Observations on the dry-season survival of Simulium damnosum Theo. in Ghana
Authors: Marr J. D. M. , Lewis D. J. 
Published: July 2009

Observations were carried out, chiefly between March and June 1962, in an area centred on Bolgatanga in northern Ghana in the hope of finding out how Simulium damnosum Theo. survives the ‘ dry season ’. The term ‘ dry season ’ is used here for the unfavourable season when running water in the rivers is evidently absent or is insufficient or perhaps unsuitable for the development of any, or more than a negligible number of, individuals of S. damnosum from egg to adult. The incidence of this season varies from year to year and does not correspond to the season without rain. It may usefully be divided into reduced-flow, main dry, pre-flow and early-flow periods.Search was made for larvae and pupae before rivers began to flow, without result. Observations were made on the numbers of flies biting, general appearance, wing measurement, antennal colour, mid-gut, fat-body, ovaries and parasites, chiefly at the beginning of the rainy season, in an attempt to trace the history of the species during the preceding weeks. Flies appeared before the rivers began to flow but did not give evidence of having lived for months. On the days when two rivers began to flow, considerable numbers of flies were caught, and most of those dissected proved to be parous and had evidently been in the adult stage for some days. A nematode parasite of the Malpighian tubes was found only in April, with one exception up to 10th May, and was probably associated with the dry-season biology of the host.The possibility that S. damnosum migrates from permanent foci, or exists near its breeding places in one or more stages at different times, is discussed. Migration from afar seems very unlikely. The species survives in the adult stage for at least part of the ‘ dry season ’, but more information is required to complete the picture.Survival is apparently not dependent to a significant extent on perennial breeding locally, and there is, therefore, no easy solution to the problem of control. Operational research might show if there is a carry-over generation and if control after the rains and towards the end of the breeding season would prevent it from developing. There is some indication that the risk of infection with Onchocerca tends to be low at the end of the ‘ dry season ’, which is a time when control would be particularly difficult.The results of observations on wing measurements, antennal colour and the peritrophic membrane are given in an Appendix.
The insect infestation of sorghum stored in granaries in Northern Nigeria
Authors: Giles P. H. 
Published: July 2009

The majority of sorghum in Northern Nigeria is stored unthreshed in farmers' granaries made of dried mud or plant materials such as grass matting and cereal stems. During the course of survey work and insecticide trials in 1959–61 it was possible to examine many samples of unthreshed sorghum from granaries throughout Northern Nigeria. It was found that the distribution of insect species within the Region is not uniform. Sitophilus oryzae (L.) and Sitotroga cerealella (Ol.) are the major pests. Sitophilus zeamais Motsch. was found only in the southernmost area. Heavy infestations of Rhyzopertha dominica (F.), Lasioderma serricorne (F.), Cryptolestes ugandae Steel & Howe, Oryzaephilus mercator (Fauv.), Tribolium castaneum (Hbst.) and T. confusum Duv. usually occur. Attagenus gloriosae (F.), Ahasverus advena (Waltl), Palorus ficicola (Woll.), P. ratzeburgi (Wissm.) and P. subdcpressus (Woll.) are occasionally important.R. dominica, Bruchidius sp., G. ugandae, Planolestes cornutus (Grouv.), S. oryzae, Brachypeplus sp., T. castaneum, Sitotroga cerealella (all of which occurred on the standing crop), L. serricorne, Typhaea stercorea (L.), O. mercator, Palorus spp. and Tribolium confusum were found in sorghum sampled before storage. Insects from infested stores were found to infest sorghum growing nearby. Prestorage infestation alone can result in subsequent heavy populations of insects in the store. Cross-infestation between granaries almost certainly occurs.Under Samaru conditions, where sorghum is harvested in November–December, insect populations remain at a low level in granary-stored unthreshed sorghum until after June, when the moisture content rises in the rainy season. In sorghum stored for nine months in provincial trials, more damage occurred during the last three months than during the previous six months of storage.Sorghum heads stored in granaries made of plant materials such as grass matting and cereal stems are more severely damaged by insects than those stored in dried-mud granaries. This is probably due to a higher rate of immigration in the former.In threshed grain stored in a mud granary, moisture content and damage by the most abundant insect, Sitophilus oryzae, decreased with depth. The insect population rose to a peak in November, two months after the maximum moisture content. The numbers fell rapidly during the following dry season. The annual cycle of insect damage was also assessed by taking fortnightly samples of threshed grain from a local market. S. oryzae was the most numerous insect, but even this species was uncommon from December to May, during the dry season.
Observations on the biting habits of mosquitos in the forest canopy at Zika, Uganda, with special reference to the crepuscular periods
Authors: Haddow A. J. 
Published: July 2009

The results of sixty 24-hour catches of mosquitos carried out with man as bait in the forest canopy at Zika, central Uganda, are discussed. In these catches the arrival of mosquitos was recorded to the nearest minute.The rapid changes of light intensity in the equatorial twilight are discussed in relation to a series of readings made at Entebbe.It is shown that among species that show a crepuscular peak of biting activity (Aedes ingramiEdw.,A. africanus(Theo.),Mansonia fuscopennata(Theo.) andM. aurites(Theo.)) the peaks do not all occur at the same time, but form a succession.Moonlight (at least in the forest canopy) has no apparent effect on the timing of these crepuscular surges of biting activity.One species (M. fuscopennata) also shows a peak of biting activity before sunrise. This peak is closer to sunrise than the evening peak is to sunset. A brief reference to current work carried out above the canopy, where foliage, shadows, etc., do not complicate the environment, shows that this phenomenon occurs in other species also. It is concluded that in these species the morning peak must almost certainly occur in light of much greater intensity than the evening peak.The implications of these findings are discussed with reference to the questions of endogenous rhythm and exogenous stimuli.
The control of Hylemya arambourgi Séguy (Dipt., Anthomyiidae) on barley
Authors: Bullock J. A. 
Published: July 2009

The larva of Hylemya arambourgi Séguy is an important pest of barley in Kenya; it attacks the shoots, causing death of the central leaf. Three to four shoots are destroyed by each larva, and an early, heavy infestation, under conditions of drought, may cause complete loss of the crop. Where a crop is obtained, the effect of an infestation on yield is difficult to assess, because climatic factors play a major part in determining ultimate figures.The life-cycle is briefly described.Trials with various methods of chemical control showed that only seed treatments were consistently effective. Other forms of pre-sowing treatment were ineffective at economic rates of application, while a spray applied after an attack had developed was of little value. Sprays applied prior to the development of an attack gave variable results but were usually ineffective.The most satisfactory chemicals used as seed treatments were dieldrin and heptachlor. Aldrin and endrin were sometimes effective, while γ BHC, carbaryl, dimethoate and thiometon were ineffective. A formulation of chlordane was also ineffective, but this failure may have been due to poor dispersion on the seed. It is probable that the insecticide acted mainly as a systemic poison, since larvae rarely enter the soil before the time of pupation.Both dieldrin and heptachlor were initially used at rates of 4·6–5·0 oz. of active ingredient per 100 lb. seed, but usually gave as good results at rates of 3·5 and 3·2 oz., respectively. Dieldrin gave a measure of control at even lower rates.The prospects for cultural methods of control appeared slight. No evidence of varietal resistance was obtained, while the possibility of control by restrictions on the sowing season is ruled out by the lack of evidence of diapause and the probability that Pennisetum clandestinum and other Gramineae, such as Chloris gayanaand Setariasp., serve as alternative hosts. For the same reasons, it is considered unlikely that any change in the position of barley in the seven-year rotation would have any effect on the level of infestation.
Pests of cowpea and their control in Northern Nigeria
Authors: Booker R. H. 
Published: July 2009

Crops of cowpea (Vigna unguiculata) in Northern Nigeria are normally subject to such heavy attack by insects that the potential yields are seldom realised. The most important pests are Maruca testulalis (Geyer), which damages flowers and pods, Piezotrachelus varium (Wagn.), which attacks seeds, and the Coreids Acanthomia brevirostris Stål, A. horrida (Germ.), Anoplocnemis curvipes (F.) and Mirperus jaculus (Thnb.), all of which destroy pods. Pests that attack the pre-flowering stages of the cowpea are economically less important. Field surveys showed that, in 1961, Maruca testulalis, P. varium and Coreids together destroyed 62, 92 and 19 per cent, of the potential crop of seed from sowings in June, July and August, respectively. The corresponding percentages for 1962 were 55, 75 and 29, respectively.The effectiveness of insecticides in the control of the pests that attack after flowering has commenced was investigated in field trials at Samaru, Northern Nigeria, in 1961–63. The results showed that large increases in yield could be obtained by spray treatments starting at the first appearance of the flowers. The best of these, consisting of 1 lb. DDT with 0·1 lb. BHC per acre applied six times at weekly intervals, gave an average yield over the five trials of 1,623 lb. dry seed per acre, which is a substantial increase over the estimated national average of 158 lb. per acre. Three applications of DDT/BHC, and six or three applications of Sevin at 1 lb. per acre, gave poorer results on the whole. Insecticidal treatment reduced the incidence of all pests and led to a corresponding reduction in flower losses. It also compressed the flowering period, induced earlier flowering and pod production, and caused the bulk of the crop to mature at one time. Haulm production was also reduced, and crops grown for haulms rather than for seed should therefore not be treated with insecticides.
Oviposition and length of adult life in Caryedon gonagra (F.) (Col., Bruchidae)
Authors: da Fonseca J. P. Cancela 
Published: July 2009

Oviposition and the length of adult life in the Bruchid beetle Caryedon gonagra (F.), an important pest of unshelled groundnuts (Arachis) in West Africa, were studied in continuous darkness in incubators at 30 and 40°C. at relative humidities of 50, 70 and 90 per cent., and at 45°C. and 70 per cent., and also under conditions of diurnal alternation of periods of light and darkness in a constant-temperature room at about 27·5°C. and 75 per cent. R.H. Newly emerged beetles were placed, singly (unmated or after a single mating) or in pairs, in tubes with 1–5 unshelled groundnuts. In addition, the influence of the absence of groundnuts was investigated.Length of life of the adults increased with decreasing temperature, increasing relative humidity, the absence of nuts (for females only) and the absence of mating (for females, and, in absence of nuts, for males). Adults survived for 3–4 days at 45°C. and 70 per cent. R.H. Optimum conditions are probably about 27·5—30°C. and 70—90 per cent. R.H., under which the adult length of life was about 21 days.The adults were sexually mature on emergence from the cocoons, and mating took place within 24 hours of emergence. Under the conditions of the experiments, the preoviposition period was between 24 and 48 hours. At 27·5 and 30°C., the mean length of the oviposition period (9—13 days) was only slightly influenced by relative humidity, being slightly shorter at the lowest R.H. (50%); an increase in temperature from 30 to 40°C. caused a marked reduction in the period.About 80 per cent, of the eggs were laid in crevices in the shell of the nut, where they are difficult to find. In the absence of nuts, the females laid readily between the cork and the glass and at the bottom of the tube.At 40°C., oviposition was inhibited at 50 and 70 per cent. R.H., but at 90 per cent. R.H. many eggs (but significantly fewer than at lower temperatures) were laid; the largest mean numbers (106–115) were laid at 27·5–30°C. and 70–90 per cent. R.H.; absence of nuts did not influence the numbers of eggs laid, but caused some irregularity in the oviposition pattern. More than one copulation appeared to be necessary for the female to lay a full complement of eggs.Under conditions of alternating periods of light and darkness, there was a daily rhythm of oviposition, with a strong correlation between numbers of eggs laid and the periods of darkness.The results are compared with those recorded in the literature.
Behaviour studies of Glossina morsitans Westw. in the field
Authors: Pilson R. D. , Pilson B. M. 
Published: July 2009

Investigations of the feeding activity, resting behaviour and seasonal distribution of Glossina morsitans Westw. were carried out at Lusulu Veterinary Research Station, Rhodesia, in 1961–63. Nine principal sampling sites were used, one in each of five distinct vegetation types and four at places where various pairs of types met. At each site, from dawn to dusk on several consecutive days in each of four seasons, tsete flies that had engorged naturally on a tethered ox were caught, marked and released, and meterorological readings were taken. Daylight observations of resting flies, both marked and unmarked, were made by searching the vegetation from ground level to a height of 25 feet (with the aid of ladders) and also by placing nets over inaccessible resting places, such as ant-bear holes, at the hottest time of day, thus trapping the flies that emerged later. Attempts to determine the night resting places by releasing flies marked with reflecting paint were unsuccessful.The results showed that the feeding activity of G. morsitans was restricted to temperatures between 18°C., below which the flies were inactive, and about 32°C., above which they echibited a negative reaction to light. Feeding ceased abrupthy with the onset of darkness, and these was some evidence that activity was reduced by very high light intensity during the middle hours of sunny days. The diurnal pattern of feeding activity varied considerable from season to season but relatively little between vegetation types. A sex ration near equality was observed amongst flies caught feeding on oxen. The proportion of marked flies recaptured (i.e., feeding a second time on a bait-ox) was low, ranging from 0 to 12 per cent. according to vegetation type and season: it was higher for males than for females.During daylight, the boles and branches of trees were used as resting places in all vegetation types, branches (especially horizontal ones) being preferred at most seasons. When temperatures rose above 32°C., however, the flies removed to resting places in deep shade, e.g., ant-beat holes, rock crevices, tor holes in trees and the fluted boles of dark-barked trees. Searching at night with electric torches failed to reveal the resting places used at that time.The catches of feeding flies indicated that a wide range of vegetation types at Lusulu were inhabited by G. morsitans at all seasons and that, with the exception of males in riverine vegetation in the hot dry season, vurtually no concentration of flies took place in any specific vegetation at any time of year. These findings are discussed in relation to control by discriminative clearing.
Seasonal movements of swarms of Locusta migratoria migratorioides (R. & F.) in western Africa in 1928 to 1931
Authors: Batten Anne 
Published: July 2009

Cartographical analysis of the distribution of recorded swarming populations of Locusta migratoria migratorioides (R. & F.) in western Africa for the first four years of the 1928–41 plague of this species has shown seasonal latitudinal displacements in each year with a nroth-to-northweastward movement of swarms during the monthe February-March to August-September, and a south-to-south-westward return during the priod October until the end of the year or January or Ferbruary of the following year.Changes in the position of the northern limit of distribution of swatms in western Africa from month during 1931 have indicated a probable relationship between its position and that of the Intertropical Front, in its seasonal displacement, the position of the surface front being inferred from that of the 10-mm. isohyet. From February to September 1931, following the northward displacement of the Intertropical Front and the northward penetration of south-westerly winds, a general northward displacement of swarms occurred. Similarly, following the southward advance of northerly winds, there was a southward displacement of swarms.There was an eastward movement in the main latitudinal displacement. This was particularly marked in 1929 and 1930. By September 1929, the infestation that in April had been restricted to parts of south-western Guinea and norther Sierra Leone had spread north-eastwards to cover the greater part of the Voltaic Republic and southern Mali; from December 1929 to January-February 1930, following the south-westward movement from late September to November 1929 which confined swarms to the countries bordering the Atlantic and the Gulf of Guinea. there was a spread eastwards along the coastal areas from south-eastern Ghana to southern and eastern Nigeria; and following the main northward movement of swarms which began in western AFrica in April 1930, there was, from May-June onwards, a pronounced eastward migration to the central and eastern parts of the continent. Each of these eastward movements occurred in areas where, at that particular time of year, the prevailing winds would be from the south-west.The deduced movements suggest that swarms of Locusta in western Africa move downwind, and that the principal seasonal changes in the distribution of swarms in that area occur in response to the latitudinal displacement of the Intertropical Front and its associated wind field.