bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Trials of Larvicides against Culicoides with a Discussion on the Relationship Between Rainfall and Larval Control
Authors: Kettle D. S. , Parish R. H.
Published: July 2009

Further observations and trials were conducted with insecticides against larvae of Culicoides impunctatus Goetgh. on Soutra Hill, Midlothian. The analysis of the data was complicated by a large natural reduction (76%) which occurred in the untreated plots. Nevertheless, it appears that the following dosages of insecticidal preparation were still active two years after application:—(a) 50 and 200 mg. p,p′DDT/sq. ft. applied as a dust, wettable powder or water-miscible concentrate (99% control), (b) 50 and 200 mg. γ BHC/sq. ft. as a wettable powder or 200 mg. γ BHC/sq. ft. as a water-miscible concentrate (95% control), (c) dieldrin at 25 mg./sq. ft., which gave 97 per cent, control and (d) chlordane at 50 mg./sq. ft., which gave 84 per cent. control.

The effect of spray volume on insecticidal effect was investigated by applying 25 mg. and 50 mg. p,p′DDT/sq. ft. in the following spray volumes:—5, 10, 15, 25, 50 and 80 gals./acre. The effect of 50 mg./sq. ft. at each volume was less marked than in the previous work, when only one concentration was used. Weather conditions in the present season were unusual, but there were indications that moderate spray volumes (15 and 25 gals./acre) give the best results at this dosage of insecticide. The combined results for 50 mg./sq. ft. at all volumes gave only 43 per cent, residual control, while those for the lower dosage showed no residual control.

The results are discussed with reference to the effect of rainfall on residual control. It is concluded that the volume of spray applied is unimportant provided the droplets of insecticide are closely and evenly distributed on the mossy vegetation that overlies the peat. Subsequent prolonged rain, of the order of 20 inches, is required to attain the most effective distribution of the insecticide, which is at the surface of the peat, where the eggs are laid and the newly hatched larvae will come in contact with the poison.
The response of cotton to pest attack
Authors: Wilson A. G. L. , Hughes R. D. , Gilbert N.
Published: July 2009

From trials with cotton (variety Stoneville 7A) grown on the Ord River Irrigation Area of Western Australia, the results of delaying insecticide protection of crops against Heliothis attack by four and eight weeks were re-examined. With each delay the crop set later when temperatures were cooler, the plants older and larger, and the accumulated insect damage greater. Yet there was no significant difference in the final number of bolls produced in each crop. The growth of cotton and the compensatory mechanisms of the plant indicated by the data were simulated by a simple computer model. A modification of the model to simulate the response of a cotton plant to attack by Heliothis larvae was also developed. Output from the model suggests that, under the conditions of the experiment, there is a theoretical maximum number of bolls produced by this cotton variety. To produce this maximum crop requires complete protection from Heliothis larvae, but the period of protection can be minimised.
Hourly distribution of larviposition by Glossina austeni Newst. and G. morsitans morsitans Westw. (Dipt., Glossinidae)
Authors: Nash T. A. M. , Trewern M. A.
Published: July 2009

The main purpose of the investigation was to determine when larviposition occurs in these laboratories, under conditions of constant temperature, relative humidity and light cycle.
The role of physical and chemical stimuli in the development ofin vitrofeeding techniques for tsetse fliesGlossinaspp. (Dipt., Glossinidae)
Authors: Langley P. A.
Published: July 2009

In laboratory experiments at Langford, Bristol, agar membranes were superior to Parafilm membranes for thein vitrofeeding ofGlossina morsitansWestw. andG.austeniNewst. Temperature appears to be the primary stimulus for probing but agar membranes stimulate some probing, probably because of the humidity gradient above the membrane. Agar membranes also stimulate gorging, and enhance the effect of the phagostimulant adenosine 5' triphosphate (ATP). Agar membranes may simulate conditions on and in the skin of a living host by stimulating tactile and/or hygroreceptors in the mouthparts of the probing fly.G. morsitansfemales fed on blood containing ATP concentrations up to 5 × 10−3M gave a higher reproductive rate and higher pupal weights. The rate of breakdown of ATP in bovine blood during one hour at 37°C indicated the amounts that need to be added to maintain optimal concentrations during feeding. There was positive correlation between pupal weight and reproductive rate ofG. morsitanswith the membrane-feeding system, but a maximum of only 80% of the optimal rate of reproduction and 80% of the optimal pupal weight was achieved. On living hosts this correlation did not hold, the pupal weights being higher, suggesting that the membrane-feeding system constitutes a stress factor. The stress ofin vitrofeeding does not apparently involve probing or gorging stimuli but its symptoms are those of nutritional deficiency. It is concluded that post mortem changes in vertebrate blood may affect quantitative aspects of feeding, or they may affect either the nutritional content of the blood or the ability of the insects to metabolise it correctly.
Field investigations on the effects of an organophosphorus pesticide, thionazin, on predacious Carabidae (Coleoptera)
Authors: Critchley B. R.
Published: July 2009

The effects of soil-applied thionazin on field populations of Carabidae were assessed in two fields of potatoes in Berkshire, England. Broadcast at 11·2 or 44·8 kg/ha in a light sandy loam soil, thionazin considerably reduced numbers of Carabids for up to eight weeks after application. Lower catches occurred again six months later when treated soils were rotavated after lifting of the potato crop; these were attributed to the exposure of Carabidae to thionazin residues which had leached into deeper layers of the soil. Dosages of 2·24 or 8·96 kg/ha applied in rows sometimes increased numbers of Carabidae trapped, possibly because of sublethal effects increasing locomotor activity. Carabidae affected most by the treatments were the small diurnally active species such asBembidion lampros(Hbst),B. quadrimaculatum(L.), andTrechus quadristriatus(Schr.) which were also abundant at the time when the treatments were applied. Larger species such asHarpalus rufipes(Deg.),Pterostichus vulgaris(L.),P. madidus(F.) andCalathus fuscipes(Goeze) were also affected but were generally less susceptible partly because they appeared later in the season when the pesticide had partly disappeared. The rapid disappearance of thionazin from the surface 1·3 cm of soil could account for the low susceptibilities of non-burrowing species;Asaphidion flavipes(L.) which rarely burrowed was less susceptible andHarpalus aeneus(F.) which readily burrowed was more susceptible than other species of similar size.
A new Tropiduchid (Homoptera, Fulgoroidea) infesting Chamaedorea (Palmaceae)
Authors: Fennah R. G.
Published: July 2009

A new species of Tropiduchidae, Biruga chariclo, is described from adults and nymphs intercepted by the U.S. Department of Agriculture on palm fronds imported from Mexico, and the genus is redefined.
Long-term fluctuations in numbers of the tsetse fly Glossina swynnertoni Austen
Authors: Glasgow J. P. , Welch J. R.
Published: July 2009

The tsetse fly population of Block 9 at Shinyanga, Tanganyika, consisting of 40–50 square miles of thorn bush, was studied from 1935 to 1957 by means of fly-rounds with a total length of 30 miles. The mean annual apparent density (A.D.) of Glossina swynnertoni Aust., taken as the geometric mean of the 12 monthly figures, is plotted on a graph covering 23 years, together with data for 1930–36 from another block which, however, is only doubtfully comparable. Four peaks and five troughs occur on the graph of Block 9, the highest value being 18 times the lowest. The history of the natural and artificial events which have occurred in the block are detailed as far as they are known. The minimum A.D. was that of 1938, after a number of wild animals had died of rinderpest; thereafter, the A.D. rose for several years, in spite of certain anti-tsetse measures, and none of the fluctuations subsequent to 1938 can be associated with any natural or artificial event. The amplitude of the fluctuations is small compared with records in the literature for other animal populations, and their occurrence is irregular; the last peak observed was in 1954, but limited observations in 1959 gave catches little, if at all, below those of 1954.

The data were also analysed for seasonal variations. The least monthly mean catch was that of November, the greatest, differing from the least by a factor of only 1·34, that of April. Earlier published accounts of G. morsitans Westw. (based, however, on relatively short periods) give later maxima and greater amplitudes. Annual and seasonal records of the percentage of teneral individuals among male flies and the percentage of females among non-teneral flies are also given, but these data cannot be interpreted at present.
The biology of Cryptolestes capensis (Waltl) (Coleoptera, Cucujidae)
Authors: Lefkovitch L. P.
Published: July 2009

Cryptolestes capensis (Waltl) has been reared successfully upon wheatfeed at constant temperatures of 15 to 32·5°C., at intervals of 2·5°C., and 90 per cent. R.H., and at 30°C. and 10 to 70 per cent. R.H. Newly formed adult males were found to weigh more than females bred under the same conditions. Oviposition was investigated at 90 per cent. R.H. and 17·5, 20, 30 and 32·5°C.; the highest rate was at 30°C. It was concluded that 30°C., 90 per cent. R.H. were the optimal conditions of those observed. Comparison with C. turcicus (Grouv.) which occurs in the same habitat as C. capensis, shows that the temperature limits of the former are higher, but that at those temperatures at which both species can breed, there is little, if any, difference between the total duration of the immature stages. At the observed optimum for the two species, C. capensis has a higher innate capacity for increase than C. turcicus. These observations do not account for the rarity of C. capensis in comparison with C. turcicus, and it is postulated that C. capensis is, like C. ferrugineus (Steph.), more susceptible to the harmful effects of high larval density than is C. turcicus.
A method for measuring the acaricide-susceptibility of the cattle tick Boophilus microplus (Can.)
Authors: Stone B. F. , Haydock K. P.
Published: July 2009

A simple method is described of testing the susceptibility to acaricides of larvae of the cattle tick Boophilus microplus (Can.) in Queensland, Australia, by enclosing them in packets made from rectangular filter papers, folded once and secured along the remaining three sides by spring clips, that had been impregnated with Risella-oil solutions of DDT, dieldrin, or Bayer 21/199 (coumaphos), or with deposits from xylene solutions of Dilan. The response of susceptible engorged adult females to dieldrin was tested similarly. Five out of six experiments showed statistical evidence of repeatability of results in determination of relative DDT-resistance of larvae. There was a slight increase in susceptibility of non-resistant larvae to DDT with increasing age between 7 and 28 days for fresh packets but not for re-used packets. In three out of four tests, re-used packets were significantly more toxic (up to 1·40 times) to susceptible larvae than fresh packets. In one test a loss of toxicity occurred after storage of Bayer 21/199 packets for 23 days. The possible use of this method for measuring resistance in ticks is discussed.
The control of tsetse flies (Glossina: Diptera, Muscidae) in a heavily infested area of Southern Rhodesia by means of insecticide discharged from aircraft, followed by settlement of indigenous people
Authors: Cockbill G.F. , Lovemore D.F. , Phelps R.J.
Published: July 2009

An operation is described in which approximately 100 sq. miles of heavily infested tsetse country in Southern Rhodesia, supporting both Glossina morsitans Westw. and G. pallidipes Aust. and an abundant and varied game population and formerly an area of endemic sleeping sickness attributable to Trypanosoma rhodesicnse, received six applications of 4 per cent, γ BHC in diesolene, discharged from aircraft in the form of a coarse aerosol, between May and September 1957. The area was a valley bounded by an escarpment, which provided conditions of relative isolation.

Fly-round catches of G. morsitans taken before, during and after the operation indicated that in those parts of the area that had received uniform treatment an estimated reduction in population, after the final application, of between 96·6 and 100 per cent, had been achieved, but where only the vegetation forming the riverine fringes had been treated the reduction was less. Quantitative data on the effect of the treatment on G. pallidipes were not collected, but the species ceased to be found in an investigation on sampling techniques that had been in progress in the area.

The area had been chosen for a resettlement scheme of indigenous people that was due to begin before October 1957, and the purpose of the spraying operation was to reduce the population of tsetses to a level that would permit the introduction of the people and their stock with comparative safety from trypanosomiasis. It was hoped that the number of people to be resettled would be sufficient to clear most of the tsetse habitat in their text-abstract agricultural activities and that the tsetses would be permanently excluded from the valley. Four to five years after the start of resettlement there were still several uncleared areas remaining, but the situation was continually improving, and estimates in 1962 indicated that the population of G. morsitans had remained at a low level, showing a reduction of between 81 and 100 per cent, as compared with that prevailing before the spraying operation. The stock introduced in 1957 were maintained under drug treatment, and the rate of infection with T. congolense was kept below a 3 per cent, level; no cattle died from trypanosomiasis, and their numbers had more than doubled by 1962. No case of sleeping sickness occurred.

The work described here showed that, under conditions of relative isolation, G. morsitans can be sufficiently reduced in numbers by means of an insecticidal aerosol discharged from aircraft to permit the successful introduction of people and stock, provided that adequate veterinary supervision is given, and that under these conditions settlement can prevent the recovery of a population of this species.
Further records of distribution of blowflies in Great Britain
Authors: MacLeod John
Published: July 2009

The local blowflies were sampled by bait-trapping at a number of stations in the Northwest Highlands of Scotland and their western seaboard, the Western Isles and eastern and southern England, to supplement the results of an earlier survey of the distribution of Calliphorine blowflies in Great Britain.

Of the species of Lucilia, L. richardsi Collin was as numerous as L. scricata (Mg.) in the south-east, but relatively infrequent further north, and was not found in the Northwest Highlands or Islands. L. ampullacea Villen. and L. silvarum (Mg.), though earlier found in the eastern part of the Northwest Highlands, are rare or absent on the western seaboard and in the Western Isles. L. illustris (Mg.) is relatively infrequent in the Northwest Highlands and Islands, but in these regions was found as far north as Lairg, and in the Outer and Inner Hebrides.

Of the species of Calliphora, neither C. loewi End. nor C. uralensis Villen. were found in any of the eight stations in eastern and southern England. C. uralensis was common in the Western Isles and on the northwest seaboard. C. loewi more common in the Central Highlands and apparently absent from the Islands.

Acrophaga subalpina (Ringdahl) was not taken in the stations in the east and south of England, Cynomyia mortuorum (L.) only in the three more northerly of these, north and west of the Wash, and Phormia terraenovae R.-D. at onlv one station further south, Wye.
Labobatory studies on dispersion behaviour of adult beetles in grain. I.—The grain weevil,Sitophilus Granarius(L.) (Coleoptera, Curculionidae)
Authors: Surtees Gordon
Published: July 2009

The dispersion of groups of adult grain weevils (Sitophilus granarius(L.)) was investigated under controlled conditions by observing the numbers occurring on the surface, or at various depths below it, in small bulks of grain. The effect of population density, and temperature and moisture content of the grain, on numbers at the surface was studied by using groups of weevils in 500 g. wheat, and on dispersion in the vertical plane by confining weevils, isolated or in groups of twenty, within a thin layer of 200 g. wheat contained between vertical glass plates, through which the positions of individuals could be recorded.

In grain at 25°C. and 14 per cent. moisture content, the proportion of the population at the surface was about 17 per cent. for densities of 2–100 insects in 500 g., and was only temporarily changed by adding or removing weevils at the surface; the proportion was higher at nine per cent. moisture content or at 15 or 35°C.

In grain at 25°C. and 14 per cent. moisture content, the typical behaviour pattern of individuals consisted of random vertical and lateral movements, so that there was a constant turnover within a group, but at nine per cent. moisture content and 25°C. they tended predominantly to move upwards. At 15 and 35°C., isolated individuals were stationary, but upward movement was elicited by increase in density; relatively static behaviour at 35°C. is thought to be associated with the need for water conservation. The possible relevance of these results to the detection and control of pest populations and their spread in storage conditions is discussed.
Laboratory studies on dispersion behaviour of adult beetles in grain. III.—Tribolium castaneum (Hbst.) (Coleoptera, Tenebrionidae) and Cryptolestes ferrugineus (Steph.) (Coleoptera, Cucujidae)
Authors: Surtees Gordon
Published: July 2009

The dispersion behaviour of Tribolium castaneum (Hbst.) and Cryptolestes ferrugineus (Steph.) was studied under controlled laboratory conditions. The effect of density, temperature and moisture content of grain on surface numbers was studied using groups of insects initially placed centrally in jars containing 500 g. wheat and vertical dispersion was studied by observing groups of insects in a thin plate of grain held vertically between two glass sheets. The underlying behaviour of group dispersion was studied, using isolated individuals. Over the range of conditions used (15–35°C, and 9–17 per cent. moisture content), 14–49 per cent. of groups of Tribolium and 0·2–4·0 per cent. of Cryptolestes appeared on the surface. Surface numbers in both species were depressed at each end of the temperature range. In the middle of the temperature range, more individuals of Tribolium were found on the surface in grain at 17 per cent. moisture content than at 9 per cent., the reverse being found with Cryptolestes.

Analyses of locomotory activity in Tribolium showed that in all conditions females moved around less than males. For both sexes, activity was relatively depressed in the driest grain and at the lowest temperatures. Change in position within the grain was almost totally absent at 35°C. although locomotory activity remained relatively high. In Cryptolestes, locomotory activity was likewise depressed at the lowest temperature but both sexes moved around apparently at random in grain at 14 per cent. moisture and 30°C. In grain at 9 per cent. moisture, nearly all individuals became inactive within 24 hours. These results are discussed in relation to the onset and detection of infestation in grain and to the associations of grain-infesting species.
Field trials with a presistent stomach insecticide against populations of the red locust, Nomadacris Septemfasciata (Serv.), in an outbreak area
Authors: Dean G. J. W.
Published: July 2009

In its potential outbreak areas in Northern Ehodesia and Tanganyika, sexually immature populations of adults of Nomadacris septemfasciata (Serv.) tend to concentrate in the islands of grass that remain unburnt after the annual fires that occur during the dry season. The locusts use the tall grasses as roosting sites and descend in the daytime to feed on adjacent short grasses, where these occur as constituents of an internal mosaic within the islands, or, in the case of islands composed wholly of tall grasses, on the fresh grass-shoots on the burnt-over ground surrounding them.

Two methods are described whereby emulsified solutions of dieldrin were applied in the Central Bukwa plain, Tanganyika, in 1960 as a stomach poison at dosages of 2·9 and 4·5 oz. active ingredient per acre from aircraft to the whole of individual islands showing the internal mosaic pattern (4 trials) or at 2·9, 4·5 and 8·2 oz. per acre to a swath 20 or 40 yd. wide around the perimeter of tall-grass islands (8 and 4 trials, respectively). Results were assessed by counting the numbers of locusts flushed by a vehicle driven along strips parallel to one another and 0·1 mile apart, and checked by counts of dead locusts. Mortality reached at least 90 per cent, within four days, at either dosage, following the first method, and 21–89 per cent, within 14 days following the second, being significantly greater at the higher dosages but not with the wider swath.

These results are compared with those obtained in preceding years by the standard method of applying DNC from aircraft at 20 per cent, in oil as a contact insecticide; in the latter case, the cost of insecticide was more per acre sprayed, but less per 1,000 locusts killed because the density (5 locusts per sq. yd. of grass island) in the trials was greater than in those using dieldrin (1 per 3 sq. yd.). Even so, when dieldrin was used, many more locusts were killed per sortie flown, and the total cost (of flying plus insecticide) per island was much less, and per 1,000 locusts killed very much less, than in the standard method, which nevertheless has to be used against mobile swarms because DNC is quick acting.
The inheritance of diazinon resistance in an Australian strain of Musca domesticaL.
Authors: Hart R. J.
Published: July 2009

The genetics of diazinon resistance in an Australian strain of Musca domestica L. was investigated by means of two series of repeated back-crosses of the hybrid resistant form to the susceptible. Resistance was maintained through nine and eleven generations in the separate studies. The ratio of susceptible to resistant hybrid flies found in the progeny of each cross was approximately 1:1.

In the second series, the frequency data were supported by dosage/response information on the relationship between dosage of insecticide and mortality. Together with the result of a previous study, the data furnish strong evidence that a fully dominant factor is responsible for the diazinon resistance in the Perth strain of house-flies resistant to organic phosphate insecticides.
Annual variations of dry-season populations of larvae of Busseola fusca (Fuller) in Northern Nigeria
Authors: Harris K. M.
Published: July 2009

The larval populations of Busscola fusca (Fuller), a major pest of the guineacorn (Sorghum vulgare) crop, which survive the dry season in and around villages near the Research Station, Samaru, Northern Nigeria, were assessed by sampling. The larvae of B. fusca survive the five to six rainless months in diapause in crop residues, most important of which are guineacorn stems, which are stacked in the fields after harvest. Between 1956 and 1962, 100-stem random samples were collected from as many stacks as possible within an area of about six square miles. Each of the 348 samples was dissected immediately after collection and the number of living larvae of B. fusca per sample was recorded. The mean number of larvae per sample varied annually and ranged from 7 in the 1960–61 dry season to 33 in the 1959–60 dry season. The mortality of larvae is comparatively low between January and March, when most samples were collected, and it is concluded that the date of sampling did not unduly influence the estimates of annual variations of the population. The location of sampling areas also had surprisingly little effect and, despite uneven growth of the crop, the estimates of larval populations were remarkably uniform throughout the ten sampling areas and between samples within the main sampling area of Bomo village.

It is concluded that there is considerable variation in dry-season populations from year to year. The factors causing this variation have not been determined, and it is suggested that other workers might profitably continue and expand these investigations.
Studies on the responses of the femaleAedesmosquito. IX.—The mode of attractiveness of lysine and other amino-acids
Authors: Lipsitz E. Y. , Brown A. W. A.
Published: July 2009

Of 26 amino-acids tested against a solvent control for their attractiveness to females ofAedes aegypti(L.), lysine was the most attractive and six others (threonine, 1-methylhistidine, arginine, tyrosine, glutamine and alanine) were significantly attractive; nine amino-acids were significantly repellent. Lysine converted to the monopicrate, then to the dihydrochloride and then back to the free base was attractive. The degree of attractiveness of lysine was in direct proportion to the amount of uncombined CO2it inevitably adsorbs. It is also proportional to the amount of carbamino CO2combined in the molecule. Some commercial samples of lysine contain repellent principles removable by distillation. It is concluded that the attractiveness of lysine toA. aegyptiis due to its ability to act as a vehicle for CO2, both adsorbed and in carbamino combination.
Contributions to the epidemiology of human sleeping sickness in Liberia: bionomics of the vector Glossina palpalis (R.-D.) in a forest habitat
Authors: Foster R.
Published: July 2009

Glossina, palpalis (R.-D.) was studied in three localities near Voinjama, in a forest region in north-west Liberia, where human trypanosomiasis persists only as sporadic cases. Sites were chosen with different degrees of contact between man, fly and game, in transitional vegetation on the Zeliba River, and in primary forest on the Lofa and Lawa Rivers. The general features, fauna and climate of these areas are described. Catching by nets was found to be preferable to the use of traps. Trap catches averaged about one-quarter of the corresponding net catches. The theoretical basis of ‘animal’ traps is too uncertain for their use in quantitative studies, and under forest conditions there are practical difficulties in siting them in optimum positions; they failed to catch at all at very low fly densities. Heavy rain and the dry season were unfavourable to the fly, particularly outside the forest canopy. A wet-season resting site on horizontal twigs near to the ground is described. The percentage of females in the total catch differed significantly between different habitats, but apparently was not indicative of the degree of hunger in the population. There were no great differences between the sexes in activity patterns, and activity was greatest during the apparently unfavourable climatic conditions of early afternoon. The willingness of the fly to penetrate unfavourable surroundings suggests that the clearing of forest at potential places of transmission is unlikely to afford an effective means of protection. There is some evidence that breeding was curtailed during the rains. Very few engorged flies were found. Fly numbers and distribution were not affected by normal game movements. There is no evidence that the fly was ever dependent on man for food. Where game was driven away the fly tended to follow it. Occasional human foci did not affect the number or distribution of the fly, and fly activity was not correlated with human activity. Intimate and prolonged contact between man and fly did not occur.
The bionomics of swift moths. I.—The ghost swift moth, Hepialus humuli (L.)
Authors: Edwards C. A.
Published: July 2009

The larvae of two species of swift moths, Hepialus humuli (L.) and H. lupulinus (L.), live in the soil and are common under grass in the British Isles, but do not usually have any obvious effect upon the grass. The larvae of H. humuli are polyphagous and when they occur under agricultural or horticultural crops they may cause damage by feeding on the roots. Lettuce, strawberry and chrysanthemum are most frequently damaged.

The adults, which are described, fly at dusk, the female seeking the male. The female lays between 200 and 1,600 eggs, with a mean of about 600, over a period of four days. Sweep-net catches showed the ratio of the sexes to be approximately equal, and mercury-vapour light-trap catches showed that the flight period in southern England is principally in June.

In the laboratory, never less than 80 per cent, of eggs hatched, even in dry air, and the shortest incubation period, between 11 and 24 (mean 18) days, was at 20°C. At 5°C. they did not hatch, but remained viable for at least six months.

The larvae were reared in small cells drilled in blocks of plaster of Paris, which were stood in a tray of water, or in vials containing a layer of moist plaster of Paris, and were fed on pieces of carrot.

The growth of the larval head capsules was geometric and allowed 12 instars to be distinguished at 15°C.; at higher temperatures there may be more.

The growth curve of the larvae was S-shaped with a very distinct fall in weight in each instar for several days before moulting. The daily intake of food was weighed, and the conversion rate shown to be small, ranging from 0·00058 to 0·04, as compared with 0·205 to 0·49 recorded for other Lepidopterous larvae.

At 5°C., larvae did not develop beyond the second instar, nor beyond the fourth at 10°C. The optimum temperature for their development (mean period 224 days) was 15°C., although mortality was high. They developed at 20°C. more rapidly (mean 197 days) but more died. Larvae kept in a container sunk in the soil outdoors developed more slowly than those at 15°C. and had only reached the eighth instar by February (239 days after hatching). This evidence, together with that from an artificially infested plot in the field and general field observations, suggests that the usual life-cycle lasts two years.
Laboratory studies on dispersion behaviour of adult beetles in grain. XII.—The effect of isolated pockets of damp and mouldy wheat onCryptolestes ferrugineus(Steph.) (Coleoptera, Cucujidae)
Authors: Surtees Gordon
Published: July 2009

The effects of pockets of damp wheat upon the spatial structure (dispersion) of experimental populations of adults ofCryptolestes ferrugineus(Steph.) were investigated in the laboratory. Isolated pockets of non-mouldy wheat of 18 per cent, moisture content (85 per cent. R.H.) and of equally moist wheat supporting a mould flora (mainlyAspergillus candidus) were placed in a larger bulk of wheat of 14 per cent, moisture content (70 per cent. R.H.) at 25°C. One hundred beetles were released at the centre of the top surface of the bulk, and their dispersion within it was observed one week later. The method used allowed the entire bulk (25 kg.) to be quickly broken down so that the relative numbers of individuals in each of the 64 cubes of which it was composed could be recorded. Using other apparatus, the responses of single, isolated individuals to these physical conditions were analysed.

Insects reared at 25°C. and 70 per cent. R.H. accumulated to an equal extent in the pockets of damp wheat irrespective of whether it was mouldy or not. Insects in a preferendum arena went to the drier side,i.e., to 70 per cent, as opposed to 85 per cent. R.H., and the underlying mechanism was found to be a klinokinetic response to humidity. Maintaining insects at 40 or 85 per cent. R.H. for 14 days before testing did not alter their dispersion behaviour in bulks of grain; maintenance at 40 per cent. R.H. did not alter their response to humidity in a preferendum arena, but at 80 per cent. R.H. it was abolished.

A study of oviposition behaviour showed that when there was a choice between wheat of 18 and 14 per cent, moisture content, nearly all the eggs were laid in the damper grain, both when it was mouldy and when it was not. It is considered that oviposition requirements, and to some extent trophic behaviour patterns, over-ride the hygrokinetic response when wheat is damp or damaged, but that under field conditions, where the presence of dust and broken grain throughout the bulk provide conditions suited for oviposition and feeding, accumulations due solely to hygrokinesis may occur in the drier parts of a bulk.

The results are discussed in relation to the ecology of the species in grain and to its detection and control; and evidence from this and other studies is discussed in relation to the dynamic nature of spatial organisation of insect populations in grain.
Mutations in the sheep blowfly Lucilia cuprina (Wied.). I.—Studies on genes for white eye and dieldrin-resistance
Authors: Shanahan G. J.
Published: July 2009

The inheritance of white eye in Lucilia cuprina (Wied.) was investigated by means of a series of back-crosses repeated through ten generations. Since an approximate 1:1 ratio of white-eyed: red-eyed flies was observed throughout, it is concluded that white eye is due to a single recessive gene (w). Earlier work establishing that w is on an autosome is discussed.

A test for the existence of a linkage group containing genes for white eye and dieldrin-susceptibility was then made. The exposure of back-cross progeny to discriminating levels of insecticide, and the pattern of mortality observed with scalar concentrations of dieldrin, indicated that genes for white eye (w) and dieldrin-susceptibility (rdi) are on different chromosomes.
Changes in the susceptibility of normal and resistant house-flies (Musca domestica L.) to diazinon with age
Authors: Sawicki R. M. , Green G.
Published: July 2009

In both a susceptible and a diazinon-resistant strain of house-flies (Musca domestica L.), adults of both sexes were most susceptible to diazinon immediately after they had emerged from the pupae. Their resistance increased for two days after emergence and remained steady for the next three days, and the increase was proportionately larger in the resistant strain. Taking flies 2 ± 2 hr. old as a basis, the increases in resistance by the third day were 1−2½ and 3½−6½ times for susceptible and resistant males, respectively, and 2−5½ and 9−18½ for susceptible and resistant females. In both strains, the two sexes were equally susceptible to diazinon during the first day, but later the females were more resistant than the males. The resistance factor (ratio of LD50's of resistant and susceptible strains) was least immediately after emergence and increased with age; it was 15–30 in flies 2 ± 2 hr. old and 50–90 three days later. There was no direct relation between changes in resistance and changes in the weight of the flies on aging. The resistance factor to diazinon should be measured not earlier than three days after emergence to obtain reproducible values. Removal of the ovaries in flies less than one day old did not affect the increase in resistance with age.
The growth responses ofLocusta migratoria migratorioides(R. & F.) to fluctuating temperature regimes
Authors: Clarke Kenneth U.
Published: July 2009

Fourth- and fifth-instar hoppers and adults ofLocusta migratoria migratorioides(R. & F.) were expected to three fluctuating remperature regimes in Weyco climatic cabinets and weighed daily. The regimes were 30 ± 0.25, 30 ± 10 and 30 ± 15°C., the change from one extreme to the other in the last two being made every two hours. Temperatures were accurately determined, by plantinum-resistance thermometers whose dimensions approximated to those of adult locusts, and were automatically recorded. The three thermorhythms were analysed by methods based on Fourier’s theorem, whereby a given wave form can be described in terms of a basic sine weve and a series of superimposed harmonics.

The rates of growth (weight increase) in the 4th-instar and adult at 30 ± 10°C/ were higher than at 30 ± 0.25°C. and were within 10 per cent. of the means of the rates at constant temperatures of 20 and 40°C., whereas the frowth rate in the 5th instar, and the pre-copulation and pre-oviposition periods of adults and their rate of weight loss when starved, were the same under both regime. At 30 ± 15°C., 5th-instar hoppers did not survive and, in comparison with the other regimes, the growth rates of 4th-instar hoppers and adults were very much lower, the pre-copulation period of adults was the same but the pre-oviposition period was much longer and their rate of weight loss when starved was doubled. Adults locusts were also tested at 30 ± 17.5°C., but most of them died within 24 hours and all within three days.
Larvae of Culicine mosquitos in North Iraq (Diptera, Culicidae)
Authors: Abul-Hab Jalil
Published: July 2009

In a collection of larvae of Culcine mosquitos made in northern Iraq in 1952–56 during the course of a survey of potential Amopheline breeding places in the area, the folowing genera and species were represented:Uranoaenia unguiculataEdw.,Aedes caspius(Pall.)Culiseta longiareolata(Macq.),C. subochrea(Edq.),Culex theileriTheo.,C.tritaeniorhynchusGiles,C. pusillusMacq.,C. hortensisFic. andC. mimeticusNoé. The last two species are reported here for the first time from Iraq. The records ofCuliseta suochreaandCulec pusillusare based on a single larva of each.
Behaviour and regulation of puparium formation in the larva of the tsetse fly Glossina morsitans orientalis Vanderplank in relation to humidity, light and mechanical stimuli
Authors: Finlayson L. H.
Published: July 2009

From obsevations on larvae from laboratory-reared females of Glossina morsitans orientalis Vanderplank, six stages were recognised between the time of deposition (signalled in these experiments by a simple automatic device) and completion of puparium formation, each characterised by an associated pattern of behaviour. They are termed crawling (during which there is a stron phot-negative response), circling and reversing, head retraction, barrelling (the assumption of the puparial shape), hardening, and darkening. In choice-chamber experiments, crawling larvae markedly preferred moist to dry air but showed no response to gravity. In daylight at 26°C., larvae introduced into translucent plastic tubing travelled up to 65 in. before pupating; under bettwe conditions for locomotion they would probably go further. The interval before pupation was longer the earlier in the day birth occurred and was greater in light (average 108 min.) than in darkness (average 40 min.) and least, perhaps because of the contact stimulation, in sand in darkness. When bodily contact was minimised by suspending larvae by a thread tied round or stuck to the polypneustic lobes, pupation was accelerated; this possible reflected the mechanical stimulation of the handling, for pinching the larva with forceps produced a similar acceleration.
The biology of Nanophyes sp. (Col., Curculionidae) infesting Jussieua repens in India
Authors: Sankaran T. , Krishna K.
Published: July 2009

Nanophyes sp. nr. nigritulus Boh. infests the aquatic weed, Jussieua repens (Onagraceae) in India, its larvae feeing and developing inside the fruits. Adults feed on the leaves and also on the pollen and nectar of flowers. Eggs are laid singly in the interior ovaries of flower buds or blossoms. The ovaries hypertrophy and develop into deformed fruits which, when severely infested, are also completely seedles. The number of eggs laid by six females was found to vary from 89 to 410. The female that laid 410eggs distributed them in as many as 167 flowers, 7 being the maximum number of flwers in which eggs were laid and 13 the maximum number of eggs laid per day. In the laboratory, one of the females lived for 207 days and one of the males for 93 days. The period hatched in 4–8 days, the larval period occupied 7–16 days and teh pupal period, 3–6 days. The larvae moulter three times and pupated in separate chambers that they formed before pupating. Adults emerged by biting holes in the wall of the fruit. The egg and immature stages of the weevil are briefly described. Three species of Pteromalid wasps belonging to Habrocytus, Trichomalopsis and an unidentifies genus, and a species of Eupelmus (Eupelmidae) attacked the larvae.
Sukunahikona Popeisp.n. (Coleoptera: Coccinellidae) feeding on scale insects (Hemiptera: Diaspididae) infesting coconut palm in Gujarat, India
Authors: Vazirani T. G.
Published: July 2009

Coccinellids reported to be feeding on the diaspididChrysomphalus aonidum(L.) infesting coconut palms in Gujarat, India, were found to belong to an undescribed species. This is described here asSukunahi-kona popeisp.n. and is compared with other species of the genus. A key to the species is given. This is the first record of the tribe Sukunahikoni in India.
The trap-orientated behaviour of tsetse flies (Glossinidae) and other Diptera
Authors: Vale G. A.
Published: July 2009

In field studies on Glossina morsitans morsitans Westw. and G. pallidipes Aust. in Zimbabwe, various traps baited with attractive odour were used to study the behaviour of flies in each of several stages of response to traps, from the stage of being several metres from the trap to the stage of being retained in a cage on the trap. The numbers of flies that were caught by electrocution, or were observed, as they moved forwards through the stages of trapping were compared with the numbers caught or observed moving in a reverse direction. A variety of stimuli and modifications were investigated for their effects on these movements, leading to provisional recommendations for improving the speed and efficiency of trapping. The most important recommendations were: the outside of trap should be white, with black near the basal entrances, the entrances should be provided with tunnels projecting into trap, and the inside of trap should be made white at base and black at top. The top of the trap should be an open-ended tube around the cone of netting that leads to the retaining cage. Data for Stomoxyinae, non-biting Muscidae and Tabanidae are also presented.
A mathematical approach to rating food acceptance of the harvester termite, Hodotermes mossambicus (Isoptera: Hodotermitidae) and the evaluation of baits for its control
Authors: Duncan F.D. , Nel A. , Batzofin S.H. , Hewitt P.H.
Published: July 2009

Hodotermes mossambicus (Hagen) is a harvester termite which competes with livestock for natural grazing. Control by baiting is recommended. Field trials in the north-western Orange Free State and south-western Transvaal, Republic of South Africa, showed that the two most commonly used commercial baits, with carbaryl or sodium fluosilicate as the active ingredient, are ineffective in controlling this species. A simple mathematical model was developed to rate the acceptability of grasses as food for the termite colonies. This enabled the attractiveness of the bait carriers as food for termites to be compared with that of the grasses. All five grass species tested had a similar food acceptability value, while both bait carriers were unacceptable as food. Failure of the baits was due to the fact that they were not consumed by the termites. The active ingredients was found to be effective when natural grass was used as the bait carrier. The mathematical model was extended to elucidate the effect of different baits on colony survival. This approach could be further used to rate new baits and their carriers objectively.
The origin of plagues and recent outbreaks of the South American locust, Schistocerca cancellata (Orthoptera: Acrididae) in Argentina
Authors: Hunter D.M. , Cosenzo E.L.
Published: July 2009

Factors involved in the origin of plagues of Schistocerca cancellata (Serville) in Argentina were examined using a simple model for locust development. Plagues were present in 48 of the 58 years between 1897–1954 with plague sequences occurring before 1900, 1903–11, 1913–28, 1931–38 and 1944–54. Plagues originated when winter rain fell in the outbreak areas in La Rioja and Catamarca resulting in three generations in a season. Plagues continued for 8–15 years. Their decline was usually gradual resulting from a combination of several seasons when it was dry in the outbreak areas, and only one generation per year was possible. Before 1954, locust swarms were common in 15 of Argentina's 22 provinces but it was not obvious where the plagues originated. Since then most swarms have been reported from two provinces in the northwest: La Rioja and Catamarca. Within these provinces, bands and swarms have been most common in the semi-arid outbreak area. Populations have been highest when the outbreak area received winter/spring/summer rain which allowed three generations in a season. However, infestations have never approached plague proportions in recent years because regular control of bands and swarms in the outbreak area has kept populations in check.
Reproductive performance of the African migratory locust,Locusta migratoria migratorioides(Orthoptera: Acrididae), in a cereal crop environment in South Africa
Authors: Price R.E. , Brown H.D.
Published: July 2009

The reproductive performance of the African migratory locust,Locusta migratoria migratorioides(Reiche & Fairmaire), was assessed in a cereal crop environment on the temperate Highveld of South Africa. Of the two principal crops involved on the Highveld, maize realized the highest reproductive potential during summer, wheat was successfully utilized for breeding in spring. The combined effects of food and temperature were the main factors influencing seasonal variation in clutch size. Green food was essential for continued reproduction, oviposition ceased for three to four months during winter when food resources deteriorated and was resumed in spring. Although locust size was shown to decrease significantly in early winter, this did not influence fecundity. The effects of egg resorption, female age and phase on clutch size are outlined. Despite the more adverse climate of the Highveld, the migratory locust realized higher individual natality in the cereal crop environment than that recorded previously and consequently achieved outstanding reproductive success in this alternative habitat.
Light-trap catches of Dysdercus bimaculatus Stål (Heteroptera: Pyrrhocoridae) in relation to weather and the fruiting cycle of its host-plants
Authors: Derr Janice A.
Published: July 2009

Light-trap catches of Dysdercus bimaculatus Stål and weekly phenological records of its host-plants over a period of three years on Barro Colorado Island, Panama, are discussed in relation to a year-long study of population growth at selected plants. Population build-up of D. bimaculatus occurred on a sequence of seed crops from wild host-plants in the dry season. Each year, the largest number of bugs caught in the light-trap occurred after a drop in vapour pressure deficit marked the end of the dry season. Thus, the population appears ‘poised’ to attack cotton crops maturing in the late wet season. A stepwise linear regression indicated that each year, the variance in size of Pseudobombax septinatum crops (maturing at the end of the dry season) explained the largest proportion of variance in the light-trap capture of D. bimaculatus. However, estimates from the field study indicated that Ceiba pentandra crops were more important than P. septinatum in building up numbers of adult cotton stainers. The discrepancy between the field study and the longterm phonological monitoring survey would be resolved if D. bimaculatus adults experience a dispersal flight at the end of the dry season. This flight would enable the insect to locate better-quality seed crops in drier habitats that mature in the late wet season, such as Sterculia apetala or cotton. Light-trap captures at the end of the dry season in areas such as Barro Colorado Island where Ceiba and Pseudobombax occur, could be an index to the intensity of attack on cotton crops in nearby drier areas.