bluuebunny/crossref_metadata_2025_split huggingface dataset:
The feeding of “Gammexane” and DDT to Bovines
Authors: Wilson S. G. 
Published: July 2009

Benzene hexachloride and DDT are relatively new insecticides and their veterinary value when administered orally to bovines has not yet been fully investigated.The first series of experiments showed that 0·5 gm./kg. on two successive days of D. 929, was toxic; 0·25 gm./kg. on two successive days followed by 0·125gm./kg. on the 3rd and 4th days was well tolerated, and the benzene hexachloride remained in the blood in sufficient concentration to kill feeding tsetse and ticks up to the 41st day. After a single dose of 0·25 gm./kg. the benzene hexachloride remained in the blood for only 10 to 12 days, and failed to protect the animal from East Coast Fever when it was grazed on heavily infested pasture.Five calves susceptible to East Coast Fever were dosed with D.929 and exposed to attack by the common tick species under African farming conditions. A dose of 0·125 gm./kg. given weekly protected a calf from East Coast Fever, but there was no protection when the same dose was given once a fortnight. A dose of 0·125 gm./kg. given weekly also protected, whereas 0·1 gm./kg. failed. At all these dosages the concentration of benzene hexachloride in the blood was sufficient to kill feeding G. palpalis during the period the calves were under treatment and for periods of 10 to 25 days after the final dose.D.929 given to animals suffering from East Coast Fever and Trypanosomiasis had no effect on the course of these diseases.Doses of 0·3 gm./kg. (39 mg./kg. gamma isomer) are toxic to young animals but older animals showed a greater tolerance. Hypersensitivity, muscular tremors, and general paralysis were the main toxic symptoms, and gross pathologicaal changes were most obvious in the liver and urinary system. The median lethal dose of benzene hexachloride given orally for calves is therefore lower than for small laboratory animals as recorded by Cameron (1945). Only crude benzene hexachloride powder (13 per cent, gamma) was used in the preserit experiments, but Slade (1945) has shown that this is markedly less toxic than the purified gamma powder.Little experimental work was done with DDT as the results with benzene hexachloride were more promising both in the control of ticks and tsetse.
Jassid Resistance and Hairiness of the Cotton Plant
Authors: Parnell F. R. , King H. E. , Ruston D. F. 
Published: July 2009

A wide range of material has been studied in an investigation of the relationship between “resistance” to attack by Empoasca facialis and “hairiness” of the cotton plant.A continuous range has been found between full susceptibility and very high resistance.In general relative susceptibility, as gauged by visual assessment of symptoms, has been found to correspond closely with relative infestation, determined by counts of nymphs.With attention confined to grown plants, the relative susceptibility of varieties has been found substantially constant under varying levels of exposure to infestation.Hairiness of the cotton plant has been found to show an extremely wide range in degree, style and distribution. A method has been devised for expressing hairiness numerically, taking into account both length and density of hairs.A very close and consistent relationship has been found between degree of hairiness of the under surface of the leaf, and degree of resistance to Jassid. Without exception, all thoroughly hairy types have been found highly resistant, and all non-hairy types fully susceptible. Intermediate degrees of hairiness ate associated with intermediate degrees of resistance.The relationship has been found to hold good between varieties and between plants within varieties, of the species G. hirsutum; also between plants of G. barbadense, and in segregating progenies of hybrids between these two species.The hairiness of resistant strains of cotton has been found to develop gradually with the growth of the plant; the first few leaves on the seedlings being virtually non-hairy. This lack of hairiness in the early stages of growth is associated with a lack of resistance. Hairiness and resistance to Jassid develop concurrently.The conclusion is reached that hairiness of the leaf confers resistance to Jassid and that degree of leaf hairiness, measured in an appropriate manner, is a thoroughly reliable guide to degree of resistance.Length of hairs is shown to be of prime importance, and high densities without adequate length are ineffective.The relative importance of hairs on lamina and midrib has not been conclusively determined. Both have an influence on resistance but a high degree of midrib hairiness is not essential if the lamina is hairy.Hairs on stem and petiole are shown to be of very little direct importance.
Laboratory Breeding ofAnopheles punctulatus punctulatus, Dönitz
Authors: Mackerras M. J. , Lemerle T. H. 
Published: July 2009

The room used for housing a colony ofAnopheles punctulatus punctulatusis described. Its main features were an insulation system to enable some degree of temperature control during the winter months, and eight windows to ensure that the room had good natural lighting.The adults were kept in breeding cages, which were large enough to allow the insects to manoeuvre during mating and oviposition, and designed to ensure a high humidity and at the same time expose the adults to daily fluctuations in light intensity. Provision was made for easy access to the interior during feeding and management operations.The essential feature of larval management was that the larvae were kept throughout their development as separate batches, representing daily age groups. During the first three days after hatching they were left in the dishes containing soil and water in which the eggs were laid. From the third day, they were reared in shallow glass dishes. They were fed with Farex at intervals throughout the day.
Glossina Pallidipes and open Country in the coastal Area of Kenya
Authors: Moggridge J. Y. 
Published: July 2009

Glossina pallidipes does not readily attack objects moving along the edge of vegetation forming its habitat; fewer tsetse attack under humid than Under dry conditions, but those that do seem to range further.Parties of men moving out of heavily infested thicket did not carry tsetse far into the open. Few tsetses attached themselves to the men and these became gorged within a few yards of the thicket edge. Similar results were obtained when bait cattle were used.Experimental catches in a glade showed, even during the humid season, an extraordinary reluctance on the part of G. pallidipes to approach a party moving through the glade even at so short a distance as 8 yards from the thicket, but further experiments showed that a party staying in the glade for a short time made a much larger catch.
The Biology ofLaemophloeus minutusOliv. (Col. Cucujidae)
Authors: Davies R. G. 
Published: July 2009

The three species ofLaemophloeuscommonly associated with stored products have been shown, by a survey of recorded information, to be cosmopolitan and to occur on a large variety of foodstuffs.The egg, four larval instars and pupa ofL. minutushave been described briefly and the life-history outlined.Mated females ofLaemophloeus minutuslay eggs continuously throughout their long life at the rate of about 0·5 eggs per day at 17°C. rising to 4·0 eggs per day at 30°C. Humidity changes over the range 55–90 per cent. R.H. have little effect on the rate of oviposition. Oviposition is stimulated by the constant presence of the male.
An Experiment in Control of Tsetse with DDT-treated Oxen
Authors: Whiteside E. F. 
Published: July 2009

An experiment to ascertain whether extermination ofGlossina pallidipescould be brought about by introducing large numbers of DDT-treated oxen into its habitat was carried out in a small isolated block of bush in Tanganyika.The oxen were sprayed with a solution of 9 per cent, w/v pure DDT and 9 per cent, w/v resin in groundnut oil. It was estimated that when sprayed once weekly about 70 per cent, of tsetse settling on them were killed, and when sprayed twice weekly, about 95 per cent. Oxen so treated were introduced in a numerical superiority of about 6 to 1 over the larger game in the bush, but were fewer than the small game.After 3 months in which oxen sprayed once weekly were herded in tens in the bush for ten hours each day, the population of female tsetses was reduced by about 70 per cent. After a further 2 months in which oxen sprayed twice weekly were herded in fives a reduction of 80 per cent, amongst the survivors was brought about.
Further Studies on the Loss of Insecticides by Absorption into Mud and Vegetation
Authors: Hadaway A. B. , Barlow F. 
Published: July 2009

Formulations of DDT have been applied to standard mud blocks. Toxicities to Glossina palpalis and Aëdes aegypti, and the proportions of insecticide recovered from an outer layer of approximately 0·1 mms. thickness have been compared.Absorption of DDT in oil solutions was considerable, and amounts recovered from the outer layer were only from 8–19 per cent, of the total dosage applied. Adsorption of the insecticide from the oil on to mud occurred. There was some correlation between the capillary rise of the solvent and the extent of absorption. Toxicities of the blocks to test insects were low.Using concentrations of 2 per cent., 5 per cent, and 10 per cent. in power kerosene, there was no increase in the proportion held on the surface. Application of excessively heavy dosages increased the amounts in the outer layers but there was a trend towards greater absorption, and therefore to greater waste, at the high dosages. Repeated applications similarly built up a larger dosage in the outer layer but did not increase the proportion there.Emulsions were intermediate between solutions and wettable powders as regards absorption and toxicity.Up to 77 per cent, of the insecticides applied as wettable powders was recovered from the outer layer, and toxicities were correspondingly high. When benzene hexachloride wettable powder was used there was rapid loss of benzene hexachloride from the surface by volatilisation. After fifteen days the dosage had decreased considerably and the percentage in the outer layer had fallen from over 70 per cent, to 20 per cent.Loss of DDT by penetration of the carrier oil through the leaf cuticle may occur when an oil solution is sprayed on to vegetation. The extent of penetration varies with different plants.There is an indication that small amounts of DDT are transferred from the inside of treated leaves to other untreated parts of young coffee and Avocado pear plants.Deposits of DDT on leaves exposed to ordinary climatic conditions remained toxic to tsetse flies for a longer period when applied as an emulsion than as an oil solution. Deposits from a water suspension of a wettable powder were washed off readily by rain.There is some evidence that continuous exposure to sunlight produced some chemical change in, and reduced the toxicity of, DDT deposits applied to glass plates as a solution in kerosene.
Experimental aerial Spraying with DDT against Mosquitos in Burma
Authors: Jones T. W. Tyssul 
Published: July 2009

The effect of aerially sprayed 5 per cent. DDT solution against Anopheline larvae and adults has been investigated.An account is given of a rapid field method for estimating the concentration in milligrammes per square metre.At a concentration of 2–3 mg. per square metre, aerially sprayed DDT solution had little effect on Anopheline larvae breeding in water completely covered with a species of Limnanthemum. Also at this concentration tall grass gave partial protection, whereas in open water there was a complete kill.The residual effect of DDT at a concentration of 2–3 mg. per square metre did not last longer than six days.Under negligible wind conditions, resulting in a vertically falling spray, there was no penetration into huts even when situated in the open.Drastic filtration of the spray resulted in a fall in the concentration from 2 to 3 mg. per square metre in the open to less than ·05 mg. per square metre under heavy shade, consequently shrubs at ground level in heavy wooded areas were greatly protected from contamination with DDT and afforded practically safe resting places for adults.
The Tabanidae of the Anglo-Egyptian Sudan
Authors: Lewis D. J. 
Published: July 2009

Seventy species of Tabanids occur in the Sudan. Many of the inhabitants are pastoralists, and the Tabanids have a profound effect on them, largely by causing them to remove their animals from infested areas in the rains and to undertake extensive annual migrations. New problems will arise when economic development involves permanent settlement of certain infested areas. This paper sets out the problem, and satisfactory control measures have yet to be devised.The country is briefly described.The section on individual species consists mainly of lists of localities which are shown on maps.In a general discussion of distribution faunal areas are designated for discussing Tabanids in the Sudan. The composition of the Tabanid fauna, which is mainly Ethiopian, is described. Types of habitat are indicated, and distribution is discussed in relation to systematic position. The area in which Tabanids are abundant, and their seasonal prevalence, are indicated.There are brief references to habits, particularly the attraction to inanimate objects and the fact that some species bite man on some occasions and not others.The economic effect, namely, the direct effect of bites and probable role of the flies in the transmission of cattle and camel trypanosomiasis and human loiasis, are described, mainly from published sources.The effect of Tabanids on the distribution and annual migrations of pastoral tribes is described. Attacks by flies on domestic animals and the search for pasture and water are the main causes of the very extensive rainy season migrations which are shown on a map.The problem of control is very briefly discussed.Additional information on some of the foregoing subjects is given in notes on faunal areas.
Studies on Aqueous Suspensions of Insecticides. Part IV. The Behaviour of Mosquitos in contact with Insecticidal Deposits
Authors: Hadaway A. B. , Barlow F. 
Published: July 2009

The behaviour of mosquitos in contact with deposits from aqueous suspensions of insecticides has been studied by allowing them to alight individually and measuring the time to the first flight.Anopheles stephensi females flew from all formulations of DDT on various materials after approximately the same time of 2 to 4 minutes, but subsequent kills were high only when the deposit consisted of small (less than 10 microns) particles readily available for pick-up.Mosquitos were also activated by contact with fresh deposits of BHC wettable powder P.520, but all died very quickly. They were not disturbed, however, by the vapour from BHC deposits, when contact was prevented, until in an advanced stage of intoxication. The time to the first flight from surfaces treated with BHC wettable powder increased as the deposits aged and varied with different materials according to the rate of loss by evaporation and/or sorption.Mosquitos remained in contact with deposits of chlordane, dieldrin, aldrin and toxaphene for more than 30 minutes.Experiments with a number of DDT analogues and BHC isomers indicated that lipoid solubility and molecular structure are two factors governing the rate of penetration of a compound.The reactions of other species tested were similar to those of A. stephensi but kills of Culex p. molestus were significantly different from those of the Anopheline species after contact with deposits from a DDT wettable powder.
The Construction and Calibration of an electrical Hygrometer suitable for Microclimatic Measurements
Authors: Edney E. B. 
Published: July 2009

The paper describes the construction, calibration and performance of an electrolytic hygrometer based on the principle of the “Gregory” hygrometer, but considerably smaller. Its dimensions are about 6×6×10 mm.The element consists of two platinum-clad nickel-iron electrodes, holding a spiral of continuous fibre-glass wool yarn which is impregnated with a solution of calcium chloride. The water content of this hygroscopic salt varies with humidity, so that the resistance between the two electrodes also varies. In order to measure this resistance, alternating current of a known voltage is used, and the current is measured in terms of micro-amperes. A suitable circuit is described. Air temperature is measured by a fine thermocouple permanently attached to each element.Long exposure to air above acid and water mixtures damages the elements so that calibration is best carried out without acid. An apparatus in which this can be done is described. A stream of air with a high water vapour content is cooled to a precisely known temperature which is below its saturation point, and then raised to the temperature required for calibration, so that its relative humidity is known as it passes over the element being calibrated. Finally the dew-point is again found as a check. Temperature affects the resistance of the elements, and calibration must therefore be carried out at three different constant temperatures.Curves obtained by means of this apparatus show that one element will give readings from 50 to 98 per cent. R.H. within ±2 per cent. Another element with more hygroscopic salt must be used for humidities between 60 and 10 per cent. R.H.There is an ageing process whereby the resistance of each element increases for some time after it has been constructed. This period can be shortened by exposing the elements to alternating high and low humidities for a few days. Elements which have received this treatment can be calibrated and used after six weeks, and will remain in calibration for at least a fortnight.Subsequent calibrations can be made in a simple apparatus (which is described) involving acid-and-water mixtures, but the use of filters and exposure of the elements for no more than 15 minutes avoids damage.The hygrometer equilibrates in a new humidity within ten minutes.The instruments possess certain advantages: they are small, they can be read or recorded at a distance, and they do not depend upon evaporation of water, so that disturbance of the natural environment is minimised. The main disadvantages are that they cannot be exposed to saturated air without going out of calibration and that each instrument must be calibrated individually—they cannot easily be standardised for mass production.
Inter-relationships of the Parasites of the Frit-fly,Oscinella frit(L.), in eastern North America
Authors: Simmonds F. J. 
Published: July 2009

Studies are reported on the extent and importance of competition amongst larval and pupal parasites ofOscinella frit.In Ontario, 30–40 per cent. of frit larvae are parasitised byHexacolain July–August and superparasitism is thus likely. Subsequent attack byPolyscelismay occur, but probably unsuccessfully.Competition between the larval parasites and the pupal ecto-parasitesCallitulaandSpalangiais generally slight, because the former species is not abundant and the latter tends to select only healthy hosts.Experiments are described to test the inter-relations of the three pupal parasites by exposing puparia ofDrosophila melanogasterto two species simultaneously and in sequence.WhenCallitulaandSpalangiaare allowed to oviposit simultaneously, the former is more successful when hosts are relatively few, but otherwise the two species are equally successful. WhenCallitulaparasitises puparia recently exposed toSpalangia, equal numbers of the two parasites emerge, but in the reverse experimentCallitulais superior.Callitulais able to parasitise successfully a proportion of puparia already containingSpalangiawhatever the age of the latter; matureSpalangiathus attacked are mostly killed.Similar comparisons ofCallitulaandSpalangiawith the endoparasiticLoxotropashow thatLoxotropais inferior to both the others, but that all three show marked avoidance of multiple parasitism.In general, there is little interference between the various species in the parasite complex associated with the frit-fly.The parasite complex associated with the frit-fly appears to be one that is very well balanced, there being little interference between the various species involved. Moreover, when, for any reason, one species does not attain its accustomed degree of parasitism, this is offset by an increase in the numbers of one or more of the other species.
Aphidius granarius, Marsh., in Relation to its Control ofMyzus kaltenbachi, Schout
Authors: Arthur Don R. 
Published: July 2009

1.Aphidius granariusis an internal parasite ofMyzus kaltenbachi, where the latter is found infesting corn crops in South Wales.2. The emergence of the adult parasite is described. Mating takes place within two hours of emergence, the females may be mated with more than one male.3. A brief description of the morphology of the egg, larval, prepupal and pupal stages is given.4. The rate of reproduction of the females ofA. granariusis high, with female: male as 12·9: 10. Unmated females always produce males.5. The adult parasite under normal conditions lives for 21–27 days and flies readily under favourable meteorological conditions. Within limited areas dissemination may be brought about most effectively by mature parasitised apterae.6. The factors limiting the effectiveness of the parasite are briefly described. The degree of control at the end of May in the field may approximate to 90 per cent.
A new and economically important Species of Anagyrus from Africa
Authors: Compere Harold 
Published: July 2009

The species described here, Anagyrus beneficians, sp. n., can easily be distinguished from the great majority of species by the colour of the flagellum, which is completely black. Another good diagnostic character that will aid in the identification of this species is the arrangement, in six longitudinal rows, of the coarse dark setae on the frontovertex.Relatively few species of Anagyrus have been described which have the flagellum wholly black. Among these species are : nigricans, Perkins, fusciventris, Gir., nigriflagellum, Gir., subnigricornis, Ishii, punctifrons, Timb., marquesanus, Timb., orbitalis, Timb., and longicornis, Mercet. Specimens of only one of these species are available for study, namely A. fusciventris, Gir. The species described as new is very much like A. fusciventris in all the major structural characters. Both belong to a group of species characterised by a very short ovipositor. These two species differ in some of their minor characters. In A. fusciventris, the tips of the forewings appear hyaline or silvery, due to a narrow band of refractive cilia at the apex of the blade. In A. beneficians, the forewings are uniformly ciliated. The three species described by Timberlake, from the Marquesas Islands, punctifrons, marquesanus, and orbitalis, have the head, thorax, and abdomen black, in colour unlike A. beneficians. Likewise, the species described by Girault, from Australia, A. nigriflagellum, differs in coloration, the head and thorax are orange yellow. In A. nigricans, the apex of the pedicel is reddish, while in the new species it is wholly black. In A. subnigricornis, the scape is marked with white at the base as well as near the apex, and the frontovertex at the anterior ocellus is as wide or slightly wider than the head width, in which respects it is unlike A. beneficians. In A. longicornis, Mercet, the abdomen is truncate at the apex, the pedicel reddish, and the head and thorax yellow ; all of which separate this species from A. beneficians. In this brief resumé it is possible that some species have been overlooked which have the flagellum completely black. However, the conditions under which Anagyrus beneficians originally existed and its subsequent introduction into Kenya Colony strongly indicate that the species has not been described previously.