bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ‘White-clubbed’ form ofSyntomosphyrum(Hym., Eulophidae) parasitic on tsetse flies
Authors: Saunders D. S. 
Published: July 2009

Cross-mating experiments are reported between adults of the typical, darkclubbed form ofSyntomosphyrum glossinaeWtstn., obtained from pupae ofGlossina pallidipesAust. from Kenya and ofG. palpalis(R.-D.) andG. morsitans submorsitansNewst. from Northern Nigeria, and the ‘white-clubbed’ form ofSyntomosphyrum, originally reported by Waterston from Nyasaland, obtained from pupae ofG. morsitansWestw. from Tanganyika.Fertilised eggs, giving rise to offspring of both sexes, were produced only by crosses between the strains of typicalS. glossinae. Crosses in either direction between the ‘white-clubbed’ form and typicalS. glossinaeresulted in all-male progeny, presumed to develop from unfertilised eggs. It is considered that this is evidence of a physiological barrier to reproduction between the two forms. The ‘white-clubbed’ form is therefore regarded as a distinct species.
The Measurement of Size in tsetse flies (Glossina)
Authors: Bursell E. 
Published: July 2009

A convenient and accurate measure of size is necessary for studies on the physiology of tsetse flies (Glossina). Residual dry weight (i.e., dry weight minus fat) is adequate as regards the larva, pupa and teneral fly, but cannot be used for flies that have taken their first blood-meals. A linear measurement provides an index of size that remains constant throughout the life of the fly, but the use of the length of the middle part of the fourth longitudinal vein in the wing has certain disadvantages, and a measure of surface was thought preferable. That finally adopted was a function of the dorsal thoracic surface; details of it are given and a close correlation was demonstrated between it and residual dry weight for females ofG. morsitansWestw. bred in the laboratory from puparia maintained at 28°C.The relation between this measure and the weight of the newly emerged fly is affected by the temperature at which the pupal stage is passed; above approximately 25°C. the surface area of flies of any given residual dry weight decreases quite sharply, so that puparia of a given weight produce smaller but relatively heavier flies at 30 than at 25°C. This holds good also forG. pallidipesAust. andG. swynnertoniAust. The dependence of surface area on the temperature at which development has taken place unavoidably complicates the use of this measurement in work on transpiration; it also limits the application of the theory that stresses acting on the pregnant fly may be gauged from the size of flies two months later, and suggests that where the mean temperature of pupal sites is likely to exceed 26°C, any inference should be based on puparial rather than adult size.
Observations on the Simulium neavei complex at Amani in Tanganyika.
Authors: Lewis D. J. 
Published: July 2009

The paper deals with two members of the Simulium neavi Eoub. complex found at Amani in the forest of the Usambara Mountains, Tanganyika Territory. They have already been described but are at present termed the Amani unhanded and banded forms, scientific names being witheld until the taxonomy of the whole complex is better understood.Some methods of study are described.Pupae of the unhanded form constituted a large proportion of the total number found on the common local crab, Potamon (Potamonautes) lirrangensis Eathbun, which amounted to roughly one pupa to seven crabs. This form predominated in the lower and more open parts of the drainage system examined. The adults were not seen to bite man. This and the banded form were found at a much lower altitude than any hitherto reported for the complex, probably owing to the particular nature of the local climate. Neither form was abundant.The larvae and pupae of the banded form, like the unhanded one, live externally on the crabs. The variability of wing size of the banded form is described. Observations were made on the internal anatomy of the adult with special reference to the ovaries in which the follicular relics are usually very large, indicating that the female probably bites soon after laying eggs. As in S. damnosum Theo. there is an easily recognisable class of old flies with clear Malpighian tubes. Nulliparous and parous flies have rather different biting cycles. The banded form bit man readily but only about five were taken per hour in good catching places and far fewer elsewhere.Human onchorcerciasis has been reported from Amani but is not known to do any harm there. The existence of the disease in the presence of rather small numbers of Simuliids is of interest in relation to a belief that S. neavei is a more efficient vector of onchocerciasis than is S. damnosum. Out of 359 banded females dissected 41·2 per cent, were parous and 12·8 per cent, of these were infected with nematodes, at least some of which were not Onchocerca volvulus.Taxonomy, the ovarioles and the Simuliid-crab association are discussed. The formation of the large follicular relics of the banded form is considered in relation to the history of the follicular epithelium before and after ovulation. The crab association is regarded as commensalism-, and it is suggested that the crabs benefit the Simuliids by carrying them a short distance to a suitable current and that they thus enable them to live in fast rivers and so extend their range.
The life-history of the melon weevil, Baris granulipennis (Tourn.), in Israel
Authors: Rivnay E. 
Published: July 2009

Baris granulipennis (Tourn.), originally described from Egypt, has become a serious pest of water-melons (Colocynthis citrullus) in Israel, where hitherto its presence has not been recorded, and has been found on melons and cucumbers, but not on vegetable marrow or squash. Economically serious damage results from girdling of the stem end of the fruit by the female, prior to oviposition.The incubation period of the egg, on average, is 3·7 days at 30° and 6 days at 22°C. The larvae feed on developing seeds inside the fruit and pupate there. The total development period occupied from 25 to 42 days in the summer, when the temperature fluctuated between 24 and 29°C. The cocoon is made by glueing minute pellets together. These consist of dried pulp from the fruit mixed with a secretion which is ‘milked’ from the anus, and is believed to be produced in the Malpighian tubules. The preoviposition period is about four days, and the length of adult life is several weeks. There are three generations a year, and four if weather permits. Adults overwinter in hibernation. It is suggested that the increase of cucurbit cultivation, and the lengthening, by irrigation, of the cropping period, may have permitted an increase in the weevil population to pest proportions.
A biological and ecological study of the rice Pentatomid bug, Scotinophara lurida (Burm.) in Ceylon.
Authors: Fernando H. E. 
Published: July 2009

The black rice bug, Scotinophara lurida (Burm.), is widely distributed in Ceylon in areas where rice is grown under irrigation. It first became a serious pest in 1940 and, periodically since, it has assumed epidemic proportions in the Southern Province where two crops of rice are grown annually. Each crop takes from 3½ to 4 months to mature, the fields lying fallow in the intervening periods. During these periods the insects aestivate, in the adult or late nymphal stages, in cracks in the bunds in the rice-fields or on neighbouring higher ground. They remain motionless for the most part during aestivation, are gregarious and occur as much as 2 ft. below ground-level.The adults leave the aestivation sites in April and May and settle in the first crop when it is two to three weeks old, and a subsequent aestivating population behaves similarly in November and December for. the second crop. There is at first considerable flight activity at dusk, and at night, and after feeding for about a week on the rice seedlings copulation takes place and oviposition commences about ten days later.
Discriminative application of insecticide against Glossina morsitans Westw
Authors: Hocking K. S. 
Published: July 2009

A dieldrin emulsion spray containing 3 per cent, dieldrin (w/v) was applied once to the putative resting places of Glossina morsitans Westw. throughout a comparatively isolated 17-sq.-mile fly-belt in the Kabiganda Valley in southwestern Uganda between October 1957 and September 1958. Concentration areas of the fly consisted of one or more tall trees with associated understorey and thicket. The lower sides of the branches of an average of 6·75 such trees per acre were treated at a rate of about one-fifth of a pound of dieldrin per acre and at a cost of about £250 per sq. mile.Chemical analysis showed a deposit of approximately 0·8g. dieldrin per sq. metre on the surface sprayed, and although 90 per cent, of this had disappeared from the surface after about four months, it is thought that the application remains effective for this period.A very great reduction in the tsetse population was achieved. Small numbers of flies continued to be caught, but it was thought possible that these were being brought in from neighbouring valleys by buffalo, and, hence, that insecticidal application of this sort, if carried out over a wide enough area, might eradicate a tsetse population.
The use of pyrethrum formulations to controlAntestiopsison coffee in East Africa
Authors: Crowe T. J. , Jones G. D. Glynne , Williamson Ruth 
Published: July 2009

The history of the use of pyrethrum formulations to controlAntestiopsisspp. onarabicacoffee in Kenya is reviewed.The material with which the present work was done comprised three distinct forms ofAntestiopsisof doubtful taxonomic status; these were not observed to differ in their response to the insecticidal treatments used.Laboratory experiments showed thatAntestiopsiswas highly susceptible to pyrethrum and that the addition of piperonyl butoxide, a pyrethrum synergist, did not affect this response.Preliminary field experiments showed that concentrations of pyrethrins higher than those found effective in the laboratory were required. A hypothesis is advanced and established that this was due to a variable proportion of insects becoming paralysed and falling off the tree before acquiring a lethal dose.These observations and experiments suggested a two-phase method of control, using pyrethrum as a non-persistent foliage spray at an economical but effective concentration of 0·005–0·006 per cent, pyrethrins, coupled with a 5 per cent. DDT or 0·5 per cent, dieldrin dust applied to the bole of the tree to form a persistent toxic barrier. The spray removed the bugs from the tree whilst the dust prevented the return of or killed those that had only received a sub-lethal dose of pyrethrum. It seemed unlikely that such a localised application of the persistent insecticide would have any appreciable effect on beneficial insects.This two-phase treatment has been used successfully both in trials and in commercial practice for the control ofAntestiopsis. When the initial population is in excess of 20 per tree, two spray applications and one dusting are necessary to effect control.
Some experiments to determine the methods used in host-finding by the tsetse fly, Glossina medicorum Austen
Authors: Chapman R. F. 
Published: July 2009

Field and laboratory experiments were carried out in Ghana on the tsetse fly, Glossina medicorum Aust., to discover the senses used by the fly in finding its host. In laboratory experiments on vision a model locomotive with a black screen attached to it was used as a ‘host’. The flies were stimulated to move by the movement of the screen. When the screen was stopped and started for short periods the increase in activity became less each time the screen was put in motion but the fall off was less rapid than in experiments with continuous movement. The possible significance of this is discussed in the light of the normal habitat of the species in the field.In the field, G. medicorum did not respond to a moving object more than 25 ft. away but G. morsitans Westw. showed a good response at distances up to 150 ft.Tethered flies were attracted to the model screen and showed a preference for landing on the lower edge near the centre.Laboratory experiments using a guineapig and a goat as sources of smell produced no response from the flies but a strong reaction was obtained with the vapour of dilute acetic acid. In field experiments, using cows which were not visible to the fly, a very marked response to the smell of the cows was obtained. Orientation to a source of smell probably involves orientation to air movement and G. medicorum showed a strong upwind orientation in a wind tunnel even when blinded.It is concluded that G. medicorum, which lives in thicket or forest where visibility is poor, probably responds initially to the smell of a potential host. An upwind orientation would then bring it to the general vicinity of the animal and the final approach might be visual.
Studies on the dispersion and survival of Anopheles gambiae Giles in East Africa, by means of marking and release experiments
Authors: Gillies M. T. 
Published: July 2009

An account is given of marking and release experiments with Anopheles gambiae Giles in a coastal area of Tanganyika. Laboratory-reared mosquitos were used, labelled either by the topical application of paint or by the introduction of radioisotopes into the larval breeding pans. Two different isotopes were used, 32P and 35S, and recaptures were recognised by autoradiography.Routine catching stations were established within a circle of radius of 1¼ miles. Releases were made either in the centre or near the periphery of the experimental area, so that recaptures were possible up to a maximum of 2¼ miles.The following results were obtained:1. Of 132,000 mosquitos released, 1,019 were recaptured.2. The mean flight range of females released in the centre was estimated to be 0·64 mile, and of males 0·52 mile. Of females released on the periphery, the mean range of dispersion was estimated to be 0·98 mile. Individuals of both sexes were caught at the maximum range of 2¼ miles.3. The dispersion of recaptured mosquitos was shown to be non-random and to be related primarily to the distribution of human settlements.4. In certain series of releases the direction of the prevailing wind had a definite effect on the dispersal of mosquitos. But in general this was a minor factor.5. Dispersion during the first day or, in many instances, during the first two days after release was more restricted, compared with that of older mosquitos. But no difference in the distribution of catches was detected between those aged three-nine days and those more than nine days old.6. Marked females were recaptured up to 23 days after release. Apart from the first two days, the regression of density on age amounted to a daily loss of 16 per cent, of mosquitos from the experimental area. The effect of emigration could not be assessed quantitatively, but it was held to be a minor component of the total daily loss. The relatively high level of mortality suggested by these figures is attributed to the use of laboratory-reared mosquitos.7. The corrected sporozoite rate in marked females at the time of recapture was 0·8 per cent.8. The survival of males was only slightly lower than that of females.9. It is concluded from the survivorship curve that the mortality rate remained constant throughout the period in which marked females were recovered.
A study of the association between moorland vegetation and breeding sites of Culicoides (Diptera, Ceratopogonidae)
Authors: Kettle D. S. 
Published: July 2009

SummaryA major problem in using larvicides to control Culicoides is to recognise the sites requiring treatment. The relationship between plant cover and breeding of Culicoides (mainly C. impunctatus Goetgh.) was accordingly investigated in moorland areas of Scotland. Two sites were examined on Soutra Hill, Midlothian, and one each on Bannachra Muir and at Luss, Dunbartonshire. Three vegetational zones were recognised on Soutra (site 1): bogland (I), acid grassland (III) and a zone (II) characterised by vegetation preferring a much wetter habitat than either of the foregoing. C. impunctatus was virtually the only Culicoides species found in zone I; it was relatively less abundant in zone II, where C. albicans (Winn.) reached its peak, and occurred most densely at the bogland edge of zone III, where it was associated with C. cubitalis Edw., C. heliophilus Edw. and C. obsoletus (Mg.). Further into the grassland, C. impunctatus decreased while the other three species became more numerous and other species, of the group of C. pulicaris (L.), appeared. Within each main zone there were no significant differences between the various floristic groups as regards larval densities.Fluctuations in population density observed in late autumn were regarded as more apparent than real, and attributable to larval movement in response to an oscillating factor, possibly soil-water level. This movement was recognisable in all zones but was most strongly marked where the ground was uneven.On Soutra (site 2), where only zones I and III were sampled, there was remarkable consistency among the larval densities of the various groups of samples examined. This applied whether the samples were classified on their angiosperm flora, moss cover or spatial arrangement. The main source of variation was within groups and it was found that two adjacent small plots (12 yd. & z.Times; 12 yd.) which were macroscopically identical showed consistent differences over a period of ten months, covering the transition from one generation to another.On Bannachra Muir, the larvae of C. impunctatus were concentrated in an area covered by Juncus articulatus and Sphagnum where the water flowed down the hillside near the surface. C. impunctatus avoided both an area of drier leaf mould and a stagnant ditch. C. albicans, C. heliophilus and C. obsoletus preferred the ditch to the hillside flow.Around a hillside trickle at Luss, larvae of C. impunctatus and C. truncorum Edw. were abundant in subequal numbers. In spite of the restricted size of the area (about 10 sq. yd.) they never occurred in equal numbers in any set of samples, but one or the other predominated. C. truncorum showed a preference for the very wet parts.
Laboratory studies on the biology ofSyntomosphyrum albiclavusKerrich (Hym., Eulophidae), a parasite of tsetse flies
Authors: Saunders D. S. 
Published: July 2009

SummaryLaboratory studies are reported onSyntomosphyrum albiclavusKerrich, a Eulophid of interest as a pupal parasite of tsetse flies. Material for a laboratory culture was obtained from puparia ofGlossina morsitansWestw. collected in Tanganyika and sent to London by air.‘ Natural’ and ‘unnatural’ hosts of this parasite were investigated.S. albiclavusparasitised all species of Cyclorrhaphous puparia offered in the laboratory, but has only been recorded from puparia ofGlossinaunder natural conditions. The conditions which make a host suitable forS. albiclavusare discussed. The most important of these is the presence of the ‘sub-puparial space’ in which the eggs are laid, without which the host is unacceptable.S. albiclavuswill also breed on dead pupae and in puparia containing other parasites.The number of parasites emerging from the host puparium is shown to be directly proportional to its weight.The fecundity ofS. albiclavusis shown to be very variable and dependent upon the weight of host material consumed during larval life, which, in turn, reflects the density of parasites in the host puparium from which the females emerged.The duration of the parasitic phase of the life-cycle and the length of life of the adults are shown to be functions of the temperature. Length of life is also affected by the relative humidity, increased mortality occurring in low humidities and in saturated air, with an optimum for survival at about 80 per cent. R.H.It is shown that a constant temperature of 35°C. is fatal to the eggs ofS. albiclavus.The age at which females ofS. albiclavusbecome mature was investigated at three temperatures and it is shown that the rate of maturation of the ovaries is a function of the temperature.At 25°C., females ofS. albiclavusare unable to lay eggs until the third day after emergence. The number of offspring produced then falls off with increasing age of the female and very old females, although attacking hosts, are unable to oviposit.
An assessment of the economic importance of the tsetse species of southern Nigeria and the Southern Cameroons based on their trypanosome infection rates and ecology
Authors: Jordan A. M. 
Published: July 2009

Previous records and new data on infection rates in species of Glossina inhabiting southern Nigeria and the Southern Cameroons are presented, and the probable economic importance of each species is assessed.The trypanosome infection rates were highest in those species of tsetse which fed largely on Bovidae.The rarity of human trypanosomiasis in southern Nigeria and the Southern Cameroons is attributed largely to impersonal man/fly contact; under such conditions a low proportion of infected flies is to be expected. G. palpalis (R.-D.) is not an important vector of sleeping sickness, as it is in northern Nigeria. The incidence of infection in G. palpalis was generally very low; cases of bovine trypanosomiasis do occur in areas where G. palpalis is the only tsetse species present, but it is not considered to be an important vector.Little information is available on G. tachinoides Westw. and G. caliginea Aust. in southern Nigeria; both have probably been at least partly responsible for some of the rare outbreaks of sleeping sickness reported from the south. G. tachinoides may be of some significance as a vector of animal trypanosomiasis.The infection rate in G. longipalpis Wied. at the West African Institute for Trypanosomiasis Research Field Station at Ugbobigha was 21·5 per cent.; this species is believed to be of major economic importance because its presence must prevent the keeping of cattle in large areas of potential grazing.At least 13 per cent, of examples of G. medicorum Aust., G. fusca (Wlk.) and G. nigrofusca Newst. were infected in the populations examined, and the first two species are considered to be of economic importance because they penetrate potential grazing areas.G. pallicera Big., G. tabaniformis Westw. and G. haningtoni Newst. are confined to rain-forest and were found to be lightly infected; they are therefore not considered to be of economic importance, except possibly as a source of infection to cattle on trade routes.No data are available for G. nashi Potts.