bluuebunny/crossref_metadata_2025 huggingface dataset:
Field experiments on the control of wheat bulb fly, Leptohylemyia coarctata (Fall.)
Authors: Gough H. C. , Woods A. , Maskell F. E. , Towler M. J.
Published: July 2009

Gamma BHC, aldrin, dieldrin, endrin, DDT and parathion have been tested as seed dressings in field experiments for the control of wheat bulb fly, Leptohylemyia coarctata (Fall.), in eastern England. The concentrations ranged from 20 to 70 per cent, and the dressings were applied at 2–3 oz./bushel.

At concentrations of 40 per cent, or over, the first three materials appreciably reduced attack and at high infestations increased yield; within the period October to January their effectiveness increased the later the wheat was sown. There was evidence that they were less effective on highly organic soils. The other materials were either less effective or had other disadvantages.

Seed dressings of γ BHC usually reduced the number of larvae entering the plant but had little effect on larvae which succeeded in entering. Aldrin and dieldrin and probably most other materials usually had less effect on the entry of larvae but were very effective in killing larvae after entry so that the plant could subsequently recover.

Combine-drilling of aldrin or dieldrin affected the larvae in the same way as seed dressings; in one season on a peaty soil seed dressings were more effective than combine-drilling, but in another season on a mineral soil seed dressings were slightly less effective than combine-drilling. However, it was clear that with combine-drilling very much higher quantities of insecticide per acre were needed to achieve a comparable result. Both aldrin and dieldrin gave similar results.
Further Field experiments on the control of wheat bulb fly, Leptohylemyia coarctata (Fall.)
Authors: Maskell F. E. , Gair R.
Published: July 2009

Field trials were conducted in certain eastern counties of England in the years 1957–1959 to assess chemical control methods applied at sowing time against wheat bulb fly, Leptohylemyia coarctata (Fall.). Combine-drilled treatments, using fillers of aluminium silicate, brick dust, granular clay, superphosphate or compound fertiliser, included aldrin at rates from 0·3 to 5·5 lb., dieldrin at 2 and 4 lb., and heptachlor at 2 lb. active ingredient per acre, respectively. Seed-dressing treatments applied with organo-mercury fungicide included 40 and 60 per cent. dieldrin and heptachlor, 40 per cent. aldrin, 60 per cent. Thiodan, 40 per cent. γ BHC with and without organo-mercury, all applied at 2 oz. per bushel of seed; 60 per cent. dieldrin, heptachlor and Thiodan were also tested at double the intended rate of 5 oz. per bushel.

No form of chemical control was completely effective in suppressing damage but all gave some, and usually a great, improvement, particularly on late-sown or backward crops. Most of the insecticides tested gave closely comparable results. Seed dressings containing at least 40 per cent. heptachlor, dieldrin, aldrin or γ BHC were slightly more effective than combine-drilled insecticidal treatments, with the added advantage of applying only relatively small amounts of persistent insecticides to the soil.

Slight symptoms of phytotoxicity were observed on two sites in 1958 following the use of γ BHC and dieldrin seed dressings applied at the normal rate of 2 oz. per bushel and severe symptoms on two trials in 1959 to seed over-dressed with insecticide and organo-mercury; elsewhere the seed dressings employed appeared to have no adverse effect upon plant establishment.

Dieldrin, aidrin, heptachlor and Thiodan seed dressings behaved similarly in killing a high proportion of larvae within attacked shoots; γ BHC reduced the number of larvae entering the plant, but those which did succeed in entering developed in an apparently normal manner.

On fields where drilling was delayed and the attack severe, the optimum rate of combine-drilled aldrin was probably between 1 and 2 lb. active ingredient per acre. No significant increase in yield was obtained at rates much higher than 2 lb. per acre. While fine-dust formulations gave effective results, the use of a granular fertiliser base improved the flow through the combine-drill and gave increased tillering with slightly higher yields. Heptachlor combine-drilled at 2 lb. active ingredient per acre was slightly superior to aldrin at the same rate.

No adverse effects were recorded when insecticidal seed dressings and combine-drilled aldrin were used together, and at high levels of infestation the double treatment gave increased yields, though insufficient to justify its use on fields having only moderate egg populations.
The effect of radioactive phosphorus on the growth and development of Culex pipiens molestus Forsk. (Diptera, Culicidae)
Authors: Abdel-Malek Albert A.
Published: July 2009

In a study of the effect of different concentrations of radioactive phosphorus (32P) in the larval medium on the growth and development of Culex pipiens molestus Forsk., 32P was found to have little noticeable effect on the growth of the larvae up to a concentration of 3·0 microcuries (μc.) of 32P per ml., but, above this concentration, larval growth was greatly retarded.

The period of larval development was increased at concentrations greater than 1·0 μc. of 32P per ml., and pupation occurred two weeks later than in the controls. In concentrations higher than 5·0 μc./ml., pupation was completely inhibited, larvae became sluggish, stopped feeding and finally died.

The effect of 32P in the larval medium on the emergence and radioactivity of the resulting adults was also studied. On the basis of this study, it is recommended that, for efficient utilisation of radio-phosphorus in large-scale field experiments, a concentration of 32P of 1·0 μc./ml. be employed so that emerging adult mosquitos may be sufficiently radioactive to be readily detectable.
Feeding behaviour of adults of Pieris brassicae (L.) in a laboratory culture
Authors: David W. A. L. , Gardiner B. O. C.
Published: July 2009

Only a few individuals in the first generation of adults of Pieris brassicae (L.) reared in captivity will feed on artificially prepared flowers. By breeding from the eggs laid by these individuals and from a few others which have been helped to feed it is possible to maintain the stock. In each successive generation a few more individuals feed, and after about four generations most of the insects feed voluntarily. Finally, after many generations, all the insects use the flowers, and the experiments described are concerned with this adapted stock.

Many factors influence the attraction of the insects to the artificial flowers and the volume of food taken. Colour, blue or yellow, is responsible for attracting the adults to the flowers, and it is only when they are very close to the flowers and under the stimulus of colour that they show any detectable reaction to the odour of the honey solution in the flowers. Larger blue flowers are more attractive than smaller blue flowers.

The insects find the artificial flowers more easily, at first, if they are high in the cage. More honey solution is taken at 30 than at 20°C. and more in a large cage than in a small cage. When given a choice, the insects take more 10 per cent, (v/v) than 1 per cent, (v/v) honey solution and more 20 per cent, (v/v) solution than 10 per cent, (v/v) solution. When offered two of these solutions in separate cages the insects at first take less of the 1 per cent, solution than of the 10 per cent, solution. Later, presumably in an effort to obtain sufficient nutriment, they take more of the weaker solution than of the stronger solution. The insects live for a much shorter time on the 1 per cent, solution than on the 10 per cent, solution. Fresh honey solution is preferred to a solution 4–5 days old, and older honey solution is quite unsuitable as food. When the survival of adults fed on honey and sucrose solution is compared it is found that females, especially, survive longer when feeding on honey.

About 50 per cent, of the adults fed on 10 per cent, honey solution in the normal stock cage under glasshouse conditions live for 18 days. Very few survive for longer than 36 days. Starved insects all die by the llth day under similar conditions. When starved at 12·5°C. and 60 per cent, relative humidity, about half the males live for 17 to 19 days, but all are dead by about the 23rd day, whereas half the females live for about 29 days and some survive up to 40 days.
A new Australasian species of Elachertus Spinola (Hym., Chalcidoidea, Eulophidae) and notes on two European species
Authors: Kereich G. J.
Published: July 2009

A description is given of a new species of Elachertus, E. agonoxenae (Chalci-Doidea, Eulophidae), on the basis of adults reared from larvae of Agonoxena pyrogramma Meyr. in New Guinea and Agonoxena sp. in Queensland. This species has been imported into Fiji for trial in controlling A. argaula Meyr., a pest of coconut palms. The new species is compared with E. argissa (Wlk.) and E. artaeus (Wlk.), two British species for which lectotypes are here selected.
Observations on Carcelia evolans (Wied.) (Diptera, Tachinidae), a parasite of Diparopsis watersi (Roths.) (Lepidoptera, Noctuidae), in Northern Nigeria
Authors: Reed W. , Choyce M. A.
Published: July 2009

Carcelia evolans (Wied.) is a common parasite of Diparopsis watersi (Roths.) in Northern Nigeria. The egg and early larval stages have not been observed, but the latter are thought to be passed in the larva of the host. The fully grown parasite larva appears to leave its host after the latter has entered the soil and formed its pupal cell, and either immediately before, or after, the host pupates. The parasite puparium is thus formed inside the pupal cell of D. watersi, but outside the host. Before forming its puparium, the parasite larva excavates a pit in the wall of the cell, thus facilitating the subsequent exit of the adult fly, which can push through the weakened cell at this point.

The life-cycle of C. evolans is closely adapted to that of its host, with short-term generations during the cotton season alternating with a long-term, or diapause, generation during the dry season. It is believed that C. evolans goes into diapause as a minute first-stage larva, but the factors that induce diapause are unknown.

The short-term pupal period of C. evolans (12–14 days) was less variable than that of D. watersi (11–31 days) at 27±5°C. In dry conditions, inside and outside the laboratory, the mean duration of diapause for C. euolans (27·3–38·8 weeks) was longer than that of D. watersi (22·9–36·2 weeks). In pupation troughs, approximating to field conditions, the mean duration of diapause in D. watersi (43·2 weeks) was greater than that of its parasite (36·1 weeks). The spreadover of emergence of the parasite from pupation troughs was more regular than that of moths, with no peak in October.

Earlier estimates of the incidence of parasitism at Samaru are probably inaccurate because adult flies have now been shown to be capable of escaping through the apertures of the perforated zinc of the cages then in use. Estimates of the rate of parasitism, made in southern Katsina, showed that 23·1 per cent, of pupal cells obtained at Daudawa between 13th November and 24th December 1959 from cotton that had earlier been treated with insecticidal sprays were parasitised, compared with 30·7 per cent. of those obtained in the same period from unsprayed cotton four miles away. The rate of parasitism was particularly low (16 per cent.) amongst the larvae collected at Daudawa in November, due possibly to the insecticide applications that had been made earlier in the season.

These results imply that the parasite is easier to kill than its host, and an increasing use of insecticides on cotton in Northern Nigeria may therefore adversely affect the degree of control achieved by the parasite.
Studies on the larval biology of Leptoconops becquaerti (Kieff.) (Diptera: Ceratopogonidae)
Authors: Linley J. R.
Published: July 2009

Studies were carried out in Jamaica on the larval biology of Leptoconops becquaerti (Kieff.) in 1962–63.

Larvae were reared on natural breeding sites in chambers constructed from large tins, by methods that are described in detail. The features of the breeding sites are illustrated and briefly discussed.

The developmental period from egg hatching to adult emergence probably occupies four to eight weeks, depending to a certain extent upon temperature and hence on time of year. It is unlikely that the adult stage is ever reached in much less than three weeks under natural conditions. Under experimental conditions, overall survival to the adult stage was frequently greater than 20 per cent., and occasionally over 50 per cent. It is considered that survival in natural populations is probably also quite high.

Larval mortality in the experimental chambers apparently occurred maintly in the first instar, and this probably happens in nature. The results showed a relationship between percentage survival and egg number such that proportionately fewer adults were obtained from chambers with greater numbers of eggs. This was interpreted as being due to progressively more severe starvation of very young larvae in the more crowded chambers.

There was no marked tendency for adults of the more same sex to emerge first in the chambers. The sex ratio among the total of 1,039 adults obtained was 1:1.

In an experiment to investigate the diel rhythm of adult emergence, 71 per cent. of adults of L. becquaerti emerged in the four-hour period of 0300–0700 hr., and a further 27 per cent. appered between 0700–1100 hr. This is earlier than found in Culicoides furcns (Poey) in a previous experiment.
Soil application of systemic insecticides for control of woolly apple aphid (Eriosoma lanigerum (Hsm.)) in Rhodesia
Authors: Hodgson C. J.
Published: July 2009

Previous attempts to control Woolly Apple Aphid (Eriosoma lanigerum (Hsm.)) in Rhodesia are briefly reviewed. By the application of dimethoate at a rate of more than 5.0 grams a.i. or of vamidothion at more than 6.0 grams a.i. to the soil in the drip area of the tree, it was found that good control of both the foliar and root populations of the insect could be obtained on three-year-old apple trees 10 feet high. and the treatment appeared to remain effective for three seasons. It is considered that the timing of the application, the soil temperature, and the amount of wead cover are all important factors in affecting the amount of insecticide taken up by the apple trees.
Observations on the ecology of Oryctes (Coleoptera: Scarabaeidae: Dynastinae) in Madagascar
Authors: Bedford G. O.
Published: July 2009

In a study of the incidence of damage to coconut palms in Madagascar and the Comores Archipelage caused by species of Oryctes (Scarabaeidae) it was found that attack is heaviest in localities where there are abundant breeding sites for the beetle, and that tall palms are more often attacked than short ones. The most important larval breeding sites are dead standing coconut palms and decaving coconut trunks and stumps. Larvae also breed in decaying satra trunks (Medemia sp.), wood of Albizia in coffee plantations, decaying Raphia trunks, and occasionally in rubbish heaps and manure, but are only rarely encountered in decaying wood in forests. Coconut palms are important feeding sites for O. gigas, O. blucheaui and O. simiar. O. pyrrhus attacks coconut seedlings and young oil palms. Forest palms are occasionally attacked. O. ranavaloattacks bamboo on the east coast. Banana plants are occasionally attacked by O. simiar.

Scoliid parasites of the larvae of Oryctes are widely distributed but not commonly found. Gregarines in larvae are also widespread but of rare occurrence. Oxyurid nematodes were often found in the fermantation chamber at the gut of Oryctes and Cetonid larvae. The fungus Cordyceps sp. was found at only one locality where it was attacking 56 per cent. of the larvae of Oryctes. Examples of infection by the fungus Metarrhizium were rarely encountered. Namatodes often occurred in the aedeagus of adult males of O. gigas and in the bursa copulatrix and colleterial glands of adult females, as well as under the elytra. They were less common in the other species of Oryctes examined. Mermithid nematodes were found in adults of Oryctes on rare occasions. No insect parasites of the adult stage of Oryctes were found. Elaterid larvae, possibly predacious on those of Oryctes were occasionally found but did not appear to be of much importance.

It is concluded that the major factor limiting Oryctes populations in Madagascar and the Comores is the number of suitable breeding sites.
Notes on Diconocoris hewetti (Dist.) (Hemiptera: Tingidae) a pest of pepper in Sarawak (Malaysian Borneo)
Authors: Rothschild G. H. L.
Published: July 2009

An account is given of Diconocoris hewetti (Dist.), a sporadic pest of pepper in Sarawak. Most of the observations were made during a single outbreak in 1964. The egg and the five nymphal stages are described. The life cycle is completed in about 30 days at 27 ± 1°C., 80 ± 2 per cent. R.H. and the duration of individual stages is as follows: egg, at least ten days; first instar, four days; second instar, three days; third instar, three days; fourth instar, four days; fifth instar, five days; adults in laboratory cultures lived, on average, for 27 days.

Eggs are laid singly in the flowering inflorescences, and nymphs do not generally move far from their hatching sites during nymphal life. Both nymphs and adults feed on the inflorescences and infestation is particularly heavy on those spikes in which fertilisation of the flowers has ocurred but where the developing fruits do not yet exceed 1 or 2 mm. in diameter.

A survey of 60 holdings in the Kuching area showed that numbers of Tingids are very low during non-outbreak periods, only 0.4 individuals per vine (adults and late nymphal instars) being obtained during the flowering season. Numbers deceased to 0.03 insects per vine during the fruiting period. In the outbreak studied, numbers per vine varied from 3 to 10, a ten- to one hundred-fold increase over the normal levels; these figures are relative estimates only as there was no satisfactory method of estimating absolute densities in the time available.

It is suggested that serious outbreaks of Diconocoris may be due to exceptional prolongation of the flowering period of pepper vines in a district, due to cultural practices or climatic factors.

Yield losses due to Tingids in the area studied were estimated at about 30 per cent. Diconocoris can be satisfactorily controlled with sprays of various insecticides including BHC, DDT, malathion, carbaryl (Sevin) and nicotine.
Patterns of cross resistance to organophosphates and carbamates in Musca domestica
Authors: Bell J. D.
Published: July 2009

Seven strains Musca domestica L., including one susceptible strain, were tested with a wide range of organophosphates and carbamates. The results of these tests gave a broader picture of the patterns of cross resistance in strains that had been studied by previous workers and in addition showed two new types of resistance machanism, one possibly and oxidation mechanism, and the other possibly a modified AliE giving low levels of resistance to organophosphates and carbamates. This work also demonstrated the existence of at least three resistance machanisms for carbamates, two probably oxidative and the others minor machanisms associated with modified AliE.
Effect of gamma-radiation on Glossina pallidipes Aust.
Authors: Dean G. J. W. , Clements S. A.
Published: July 2009

Sufficient pupae of G. pallidipes Aust. for testing were available from the Zambezi valley only between September and early November and were of all ages. These pupae or the adult fly were exposed to gamma-radiation from a 60Co source at rates between 54 and 122 rads per min., and reproduction and mortality were studied by described procedures.

Effective pupal mortality due to radiation increased, and the proportion of males among the viable emerging flies decreased, with dosage between 4,000 and 16,000 rads. Eeproduction and survival of adult males emerging from treated pupae decreased with an increase in dosage and a decrease in pupal age at the time of treatment. Irradiation of adult males within three days of emergence produced slightly lower levels of sterility and similar survivals. Complete male sterility was rarely obtained with any of the treatments, though all the females, with one exception, were sterilised from 4,000 rads upwards, but the flies were fully competitive with untreated males and reduced reproduction below expected values. Treated males were fully capable of inseminating female flies and the sperm was motile and apparently behaved normally. Dominant lethality in the males appeared to be expressed by the failure to produce pupae and in the females by the complete failure of oogenesis.
A Contribution to Knowledge of the Blood-sucking Diptera of the Dardanelles
Authors: Austen E. E.
Published: July 2009

Although, among the very numerous species of Diptera described by the late Dr. Hermann Loew, the types of not a few are stated to have been obtained in Asia Minor, nothing whatever relating directly to the Diptera of the dardanelles has hitherto appeared in print. A paper by Loew on a collection of Diptera made near Varna* is, however, worth bearing in mind in connection with any future work on the Dipterous fauna of the Dardanelles. The paper in question includes records of seven species of Tabanidae, some of which are among those mentioned in the following pages.
The Internal Anatomy of the Clover Root Mealy-bug, Trionymus trifolii, Forbes (Homoptera, Coccidae).
Authors: Hough W. S.
Published: July 2009

The purpose of this paper is to present the more important features of the internal anatomy of a subterranean viviparous mealy-bug commonly found on the roots of clover in the eastern part of the United States. Only the female was studied, since the male has never been found. No attempt was made to present many of the details which were found to resemble homologous parts of the common oviparous mealy-bug, Pseudococcus citri, Risso, as described by Berlese in 1893.
A New Uranotaenia (Culicidae, Diptera) from Alor, Lesser Sunda Islands
Authors: Haga J.
Published: July 2009

Described from two females bred from larvae by Lieut. K.A. Aarstad, at Kalabahi, Isle of Alor, Lesser Sunda Islands, Dutch East Indies.
Effect of Salt Concentration and Reaction on the Development of Anopheles Larvae
Authors: Kligler I. J. , Theodor O.
Published: July 2009

Experiments are reported on the effect of salinity on Anopheles larvae. It is shown that A. elutus, A. superpictus and A. sergenti show a decided selective capacity for egg-laying, depositing more than 75 per cent, of their layings in fresh water or water of low saline content. It is also shown that salt concentrations of M/4 and higher are toxic to these eggs and larvae. In so far as reaction is concerned a slightly acid reaction (pH 6·6 to 6·8) favours more active development, although larvae will develop in alkaline solutions. The reaction of the medium also seems to modify the effect of the salinity. In an alkaline substrate M/8 salt solution is more favourable than lower salt concentrations, whereas in acid substrates the reverse seems to be the case.
New Curculionidae attacking Cultivated Plants (Col.).
Authors: Marshall Guy A. K.
Published: July 2009

♀ Integument black, densely squamose dorsally; the head brown, but pale round the eyes and beneath; the prothorax brown (with a slight coppery reflection) and with an ill-defined broad sinuate pale stripe on each side, adjoined externally at the base by a very indefinite blackish patch, and another very vague pale stripe on the extreme dorsal margin, the pleurae with thinner scaling, which is blackish on the upper half and grey below; the elytra brown, usually more or less heavily mottled with black and grey, but interval 1 always brown with a strong coppery reflection, the extreme base of intervals 1 and 4 blackish, that of intervals 2 and 3 and 6 and 7 grey, interval 3 with a conspicuous small black-ringed whitish spot near the top of the declivity, interval 7 mainly grey, and the lateral area below it thinly clothed with black scales and scattered grey ones; the lower surface rather more thinly covered than the dorsum with grey scales having a coppery reflection.
The Hispid Leaf-miner (Coelaenomenodera elaeidis, Maul.) of Oil Palms (Elaeis guineensis, Jacq.) on the Gold Coast.
Authors: Cotterell G. S.
Published: July 2009

Oil palms in parts of the oil palm belt in the Gold Coast Colony have suffered at intervals from the attacks of a leaf-mining beetle. Specimens of the adult beetle and full-grown larva were sent by Mr. W. H. Patterson, Government Entomologist to the Gold Coast, to the Imperial Bureau of Entomology in 1920. These were determined by Mr. S. Maulik as a new species of the genusCoelaenomenodera(family Hispidae) and described under the specific nameelaeidis(Bull. Ent. Res., x, p. 171). This species is indigenous to the West Coast of Africa, and hitherto has not been recorded outside the Gold Coast, but no doubt occurs throughout the West Coast oil palm belt. According to Mr. Maulik, 32 species of this genus are known, of which four only are recorded from Africa, the remainder being from Madagascar.
Sogatodes brazilensis (Muir), a new synonym of S. orizicola (Muir) (Fulgoroidea, Delphacidae)
Authors: Fennah R. G.
Published: July 2009

A comparison of population-samples from various localities with the respective type specimens has shown that Sogatodes brazilensis (Muir) and S. orizicola (Muir) are conspecific. Under the provision of Becommendation 24A of the International Code of Zoological Nomenclature the name S. brazilensis is suppressed and becomes a synonym of S. orizicola.
A light-sensitive apparatus for the rapid measurement of experimental feeding by insects
Authors: Soo Hoo C. F.
Published: July 2009

A simple apparatus incorporating a photographic light meter is described, which is used for rapid measurement of the amount consumed by insect larvae of black filter-paper impregnated with plant extracts.
Contact toxicities of 22 insecticides to the cocoa Mirid Distantiella theobroma (Dist.) (Hemiptera, Miridae)
Authors: Prins G.
Published: July 2009

In tests of insecticides applied in a spray tower to the ventral surface of nymphs of Distantiella theobroma (Dist.) collected from lindane-resistant and lindanesusceptible populations in cocoa plantations in Ghana, the levels of resistance of the former (ratios of the LC50's of the two populations) were 20·1, 74·4 and 73·3 for lindane, dieldrin and aldrin, respectively. There was no cross-resistance to DDT. Out of 18 other compounds tested, carbaryl (the most toxic), two other carbamates and two organophosphates were more toxic to the resistant population than was lindane to the susceptible one.
The susceptibility of sorghum to attack by the weevil Sitophilus oryzae (L.)
Authors: Davey Pauline M.
Published: July 2009

Factors affecting the susceptibility of seeds of sorghum (Sorghum vulgare) to attack by Sitophilus oryzae (L.) were investigated in the laboratory. It was known that varieties in which a majority of the seeds have a predominantly vitreous endosperm (vitreous varieties) are less attacked than those in which the majority have a predominantly mealy endosperm (mealy varieties). A method of measuring the relative amounts of vitreous and mealy endosperm in a seed was devised, and was used to classify samples from ten varieties of sorghum that had been grown in East Africa. The varieties ranged from vitreous to mealy, and the seeds from them formed the test material.

Adult weevils confined singly in tubes with seeds of either a vitreous or a mealy variety consumed more per day of the latter than of the former (about 0·2 and 0·15 mg., respectively, per mg. body-weight of weevil). When females were allowed to oviposit in seeds and the next-generation adults were counted, greater numbers were obtained from mealy than from vitreous varieties, the extreme results from a range of five being in the ratio of about 20:1. Seeds of vitreous varieties have a lower moisture-content than those of mealy ones at the same humidity, but this was not the cause of the differing numbers of adults, for the results were similar when the experiment was repeated with seeds of a vitreous and a mealy variety treated so that the moisture contents were identical. Attempts to compare the numbers of eggs laid in seeds of these two varieties gave inconclusive results; it was shown that none of the methods used was entirely reliable; in two experiments, no difference could be detected, but in a third, in which the seeds were examined by means of X-rays as well as by other means, significantly more eggs were laid in seeds of the mealy than of the vitreous variety. There was no evidence of a preference for any particular size of seed of either.

The hardness of the seeds of all ten varieties was estimated by grinding equal quantities in a mill and weighing the amounts that then passed through a 60-mesh sieve. This was done twice, with seeds at 10 and 14 per cent, moisture content. The order of hardness was not appreciably affected by moisture content, and was clearly correlated with the proportion of seeds with predominantly vitreous endosperm; the more vitreous varieties had harder seeds than the more mealy ones. It is inferred that hardness of the seed is the principal factor responsible for resistance to weevil attack.
The toxicity of insecticides to larvae of the codling moth, Cydia pomonella (L.). I.—Intrinsic toxicity and persistence
Authors: Gratwick M. , Sillibourne J. M. , Tew R. P.
Published: July 2009

The deposits found on apples at various times after application of 11 insecticides were determined by chemical analysis of samples from an orchard in south-eastern England sprayed in 1959 and 1960. The results, from samples taken simultaneously, of studies of the effectiveness of these and other chemicals for control of the codling moth, Cydia pomonella (L.), have already been reported.

The period in which 50 per cent, of an initial deposit disappeared in the field (half-life) was calculated from the chemical data and used as a measure of persistence. For comparisons of intrinsic toxicity, the levels of fresh deposits causing 50 per cent, mortality of newly emerged codling-moth larvae (LD50) were determined in the laboratory by chemical and biological tests on apples dipped in a range of concentrations of commercial formulations. The LD50's, in μg./cm.2, were less than 0·025 for carbophenothion, parathion and diazinon, between 0·025 and 0·05 for azinphos-methyl and -ethyl, between 0·05 and 0·10 for malathion, DDT and carbaryl, between 0·1 and 0·5 for DDD and dimethoate, between 0·5 and 1·5 for lead arsenate and above 1·5 for phenkapton.

Chemicals with an LD50 exceeding about 0·1 μg./cm.2 were considered not worth further investigation as codling-moth larvicides. The LD90's of the remainder were found and were taken as the minimum deposits that would have an adequate effect from the standpoint of control (minimum effective levels). From the half-life values, the periods for which the deposits found in the orchard in 1960 should have remained above the minimum effective levels were calculated; these were 24 days for DDT emulsion, 22 for DDT wettable powder, 15 for carbophenothion, 14 for carbaryl, 12 for azinphos-ethyl, 11 for parathion, 7 for malathion and 6 for diazinon. They were in good agreement with the results of the biological tests except in the case of DDT emulsion, the effectiveness of which was unexpectedly short-lived.
The replacement of Culex nebulosus Theo. by Culex pipiens fatigans Wied. (Diptera, Culicidae) in towns in Nigeria
Authors: Service M. W.
Published: July 2009

An account is given of the disappearance in Kaduna, Northern Nigeria, of Culex nebulosus Theo. from the town streams and drains and other polluted collections of water, habitats in which until comparatively recently it appears to have been the dominant species, and its replacement by C. pipiens fatigans Wied., which was formerly rarely recorded in these sites. Similarly, the latter species has replaced the former as the commonest Culicine mosquito resting in houses. Increased urbanisation and the widespread use of residual organo-chlorine insecticides within recent years have both been advanced as possible explanations for this change.

A laboratory experiment with larvae of C. p. fatigans from Kaduna and of C. nebulosus from villages on its perimeter showed the latter species to have a slightly, but significantly, quicker rate of larval development than C. p. fatigans; this would possibly confer an advantage on it in circumstances where the two species are in competition for the same larval habitats. Field and laboratory observations showed that both species can tolerate high organic pollution in their larval habitats. There appeared to be little evidence in Kaduna, or in other towns in Nigeria, to support the theory that urbanisation has been responsible for the replacement of C. nebulosus by C. p. fatigans. Laboratory and field trials demonstrated that larvae of C. nebulosus were extremely sensitive to DDT, and although resistance was not found in C. p. fatigans, this species showed tolerance of the insecticide. It is believed that, in Kaduna and most probably in other towns, the application of DDT as a larvicide to streams and drains has been responsible for the eradication of C. nebulosus there, and in the absence of competition from C. nebulosus and because of the greater tolerance of DDT shown by C. p. fatigans the latter has been able to establish itself as the dominant species.
Observations on four species of Sitona (Coleoptera, Curculionidae) occurring in Israel
Authors: Melamed-Madjar Venezia
Published: July 2009

The four commonest species of Sitona injuring leguminous crops in Israel were found during a survey in 1957–62 to be S. lividipes Fhs., S. hispidulus (F.), S. crinitus (Hbst.) and S. lineatus (L.). Adults of all four were collected in the field in December-January each year, at the termination of diapause, and kept in the laboratory for observations on their bionomics. Larvae and pupae did not survive in the laboratory, and therefore these stages were reared in the soil outside (where suitable food-plants had been grown) from eggs laid by the adults in the laboratory and kept at known temperatures until they were about to hatch. The soil was later examined daily for pupae.

Egg-laying began in December, larvae were found in January–March, pupae in March–April, and adults of the new generation in April–May. These adults fed freely but did not oviposit, and in June–July they sought shelter and entered diapause, which lasted until the close of the year. Feeding was then resumed, oviposition began shortly afterwards, and death occurred up to 250–300 days later.

The eggs of all four species are creamy or yellowish white when laid but soon become glistening black. High humidity was necessary for hatching; no eggs of S. lividipes or S. hispidulus hatched at relative humidities of 76 per cent., or less, and virtually none of S. crinitus or S. lineatus at 56 per cent, or less. In favourable humidities, the percentage hatching was reduced at constant temperatures exceeding 25°C., except in S. lineatus, in which it was not affected up to 29°C. The threshold temperatures for development of eggs of S. lividipes, S. hispidulus, S. crinitus and S. lineatus were 4·8, 4·6, 5·8 and 6·5°C., respectively, and the thermal constants were 180, 211, 166 and 145 day-degrees C. The mean larval and (in brackets) pupal periods outdoors were 52 (23), 58 (34), 36 (25) and 38 (21) days, respectively. The average numbers of eggs laid were 843, 719, 519 and 1,113 per female, and the mean numbers laid per day were 10·2, 8·5, 9·6 and 17·5. These data were obtained by feeding adults on a variety of food-plants throughout their life in the laboratory. In another series of observations, adults were fed on the same type of food-plant throughout. Egg production of S. lividipes and S. hispidulus was greatest on clover (Trifolium alexandrinum) and least on broad bean (Vicia faba) and pea, respectively; that of S. crinitus and S. lineatus was greatest on pea and least on broad bean and clover, respectively.
A taxonomic study of the species ofAntestiopsis(Hemipteea, Pentatomidae) associated withCoffea arabicain Africa
Authors: Greathead D. J.
Published: July 2009

The taxonomy of African species ofAntestiopsis, some of which are important pests of coffee, has hitherto been in confusion owing to the difficulty of finding decisive morphological characters. In the present study an attempt is made to clarify the relationships of the coffee pest species and some of their close allies by the use of both biological and morphological characters.

The species ofAntestiaandAntestiopsisoccurring on coffee in Africa are differentiated in a key, and descriptions are given of the following:Antestiopsis orbitalis(Westw.), with three clearly distinguishable subspecies,orbitalis, bech-uana(Kirkaldy) andghesquiereiCarayon, several local colour forms of these, and a few variable populations that cannot be referred definitely to any one of the subspecies;A. intricata(Ghesq. & Carayon); A.facetoidessp.n. for the species hitherto known as “ faceta ” in eastern Kenya and Tanzania;A. crypta, sp.n. confined to Katanga;A. falsa(Schout.), a rare and imperfectly known species;A. lepelleyisp.n., which does not feed on coffee; andA. littoralissp.n., from the Kenya coast, known to the writer only from museum specimens.

Evidence for the arrangement adopted is discussed, and the taxonomic value of certain morphological characters is assessed. The distributions presented on maps are discussed, and it is concluded that the activities of man are unlikely to have obscured the natural patterns. A list is given of known host-plants, which, except for those ofA. orbitalis orbitalisand formfacetus, are with only a single other exception members of the Eubiaceae. The distribution on a local scale and recent changes of abundance of species in competition are discussed, and it is shown thatA. orbitalis ghesquiereiandA. o. bechuanaappear to be spreading at the expense ofA. intricatain Uganda andA. facetoidesin Tanzania, respectively. Kesults of crossing East African species and forms show that those here regarded as species will not cross but that the subspecies ofA. orbitaliswill do so, producing intermediates that, when allowed to interbreed, are not as viable as pure strains. Finally an attempt to find morphometrical characters is discussed, and the results are given of a calculation of discriminant functions based on two characters. These, while, not conclusive, support the conclusions drawn from other evidence.
Seasonal and diurnal variations in physiological age and trypanosome infection rate of females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst
Authors: Harley J. M. B.
Published: July 2009

A series of 24-hr. catches of Glossina from bait-oxen was carried out during 16 months in 1962–63 at Lugala, Uganda, where G. pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. occur. Female flies were dissected to determine their physiological age and the presence or absence of trypanosomes. Five age-categories were distinguished, depending on whether a fly had ovulated 0, 1, 2, 3 or more (4 + ) times. Flies remained in each of the first four categories for about 11 days and the fifth therefore comprised those over 40–50 days old. Trypanosome infections were classified as brucei-type, vivax-iype or congolense-type (i.e., attributable to trypanosomes of the groups of Trypanosoma brucei, T. vivax and T. congolense) according to the sites in which they were found.

In all three species of Glossina, vivax-tjpe infections were commonest and alone showed seasonal fluctuations in incidence. Infections of the brucei-type were rare. The total infection rate (all types) in G. pallidipes and G. palpalis fuscipes was highest in or immediately after months of greatest rainfall and relatively lower in dry months; the highest infection rates in G. brevipalpis occurred a month later than those of the other two species. Over 80 per cent, of infections in all three were found in category 4+ flies, the percentage of which in the catches varied in much the same way as the total infection rate, suggesting not only that the flies live longest during wet periods but also that fluctuations of infection rate are largely due to changes in mean age. The regression of total infection rate on percentage of category 4 + flies was significant for G. palpalis fuscipes over 14 months, and for G. pallidipes over 12 months, but insignificant for G. brevipalpis.

The age-composition of catches of G. pallidipes and G. brevipalpis but not G. palpalis fuscipes varied during the day. In G. pallidipes, the percentage of older flies was higher in the middle of the day than in the early morning and late evening, and these contrasts were reflected in the infection rate, which was highest in samples taken in the middle of the day. In G. brevipalpis, the percentage of oldier flies and also the infection rate were lower during the night than during the day.

Estimates were made of the mean number of bites by infected females that would be received by one ox in one day. The number varied from month to month, with peaks shortly after periods of high rainfall, mainly as a result of changes in fly density and relatively little as a result of changes in infection rate. G. pallidipes, the most numerous species, was responsible for most of the potentially infective bites.
The ecology of the swede midge, Contarinia nasturtii (Kieff.) (Diptera, Cecidomyiidae). I.—Life-history and influence of temperature and moisture on development
Authors: Readshaw J. L.
Published: July 2009

The life-history of Contarinia nasturtii (Kieff.), a gall-forming pest of swedes, was investigated in northern England in 1958–60, particular attention being paid to the influence of temperature and moisture on development in the soil. Most of the observations were made under controlled conditions in the laboratory, although much of the material came from the field.

The adults emerge from the soil, mate, and live 1–3 days. In laboratory conditions, each female developed about 95 eggs, laid in batches of 2–50 on the young leaves of the host plant, and produced 78·7±11·4 unisexual larval progeny. The eggs require moist conditions, and hatched according to temperature after 1–10 days at 30–10°C. The larvae fed for 7–21 days at 25–15°C., producing a gall.

The full-grown larvae burrow into the soil. It was found that they either pupated in oval-shaped cocoons just below the surface, producing adults 10–48 days later (at 25–12°C.) or become dormant in spherical cocoons. At 32·5°C. the pupae died, and below 32·5°C. males developed faster than females by about 24 hours.

Dormancy is caused either by diapause, in which case the larvae require prolonged chilling before development can be resumed, or by drought, in which case development is resumed immediately in response to wetting.

The incidence of diapause increased regularly during the summer generations, probably in response to decreasing day-length, and the larvae tended to avoid diapause when placed in high temperatures (e.g., 25°C.). The firmness of diapause appeared to vary according to the conditions experienced by the feeding and full-grown larvae, but, in general, the larvae completed diapause development after 100 days at 2–5°C. followed by 30 days at 20–25°C., i.e., after exposure to conditions similar to those experienced by the diapause larvae during winter and spring.

Dormancy due to drought (quiescence) affected both non-diapause and post-diapause larvae; the former became quiescent on entering dry soil (pF>3·5–4·0), and the latter remained inactive if kept in dry or even in moist soil (pF 3·4) after completing diapause. In both cases, the termination of dormancy occurred immediately in response to a thorough wetting of the soil. The larvae left their spherical cocoons, moved to the surface, re-entered the ground and pupated in oval cocoons as if entering the soil for the first time.

Factors that delay pupation of C. nasturtii similarly delay the development of its Hymenopterous parasites and hence synchronise the emergence of the adult parasites with the host's feeding stage.
A new Japanese species of Atherigona Rond. (Diptera: Muscidae), reared from sugar-cane
Authors: Pont Adrian C.
Published: July 2009

A new Japanese species of Atherigona Rond., A. shibuyai sp.n., described from material reared from sugar-cane.
Supplementary notes on the orbitalis (Westw.) group of Antestiopsis (Hemiptera, Pentatomidae)
Authors: Greathead D. J.
Published: July 2009

The examination of samples of Antestiopsis orbitalis (Westw.) from different parts of South Africa has shown complete intergradation between the colour patterns of the typical subspecies and that of the form facetus (Germ.), hitherto of indeterminate infraspecific status, and the latter name is suppressed. Additional localities of ocurrence are given for A. orbitalis, and Antestia rufovittata Dist. is redescribed and transferred to Antestiopsis.
Species differences in scarab–pasture relationships
Authors: Davidson R.L. , Roberts R.J.
Published: July 2009

The damage caused by the larvae of four Melolonthine and one Ruteline scarab species to four grasses and Trifolium repens grown in pots was examined for interactions between species with and without manure added to the soil. Only slight interactions between scarab species and plant species were detected in the damage to pastures, and these were caused by a differential insect response to Trifolium. Most scarabs damaged Trifolium as much as they damaged the grasses, but Anoplognathus sp. appeared to avoid Trifolium in the absence of manure. Sericesthis geminata Boisd. caused more damage to Trifolium than S. vigilans (Sharp) or Rhopaca magnicornis Blkb.

The addition of manure to soil reduced to negligible proportions the damage to all pasture species except Phalaris tuberos, which suffered significantly greater reduction of foliage than other plants in the presence of manure. The highly significant alleviation of damage by manure occured with all scarab species except S. vigilans, which did not cause damage even in the absence of manure.

In this short-term experiment survival and pupation were not influenced significantly by plant species or manure.
Some factors affecting eclosion ofGlossina morsitansWestw. from pupae
Authors: Dean G. J. , Wilson F. , Wortham S.
Published: July 2009

Observations on biological variablity of pupae ofG. morsitansWestw. collected in the field, and effect on eclosion of the adult fly due to temperature, light and gamma-radiation are reported.

The homogeneity of eclosion from wild pupae varied during the year owing to variations in pupal viability. Emergence was lower in the warmer months September to December than in the cooler ones, May to August, and in one season low eclosion rates were connected with a high proportion of runts, although another analysis revealed no correlation.

Gamma-radiation redused eclosin by killing all pupae treated during their first ten days after larviposition. MOrtality of male pupae was increased by irradiation between the 15th and 13th day of pupal life, while eclosion was apparently normal with treatments given between the 16th and 29th day. Weight losses indicated that five- to ten-day-old pupae possibly did not die before the 30th day after larviposition while younger pupae containing fourth-instar larvae at the time of treatment were killed either immediately or by the 15th day.

Diurnal emergence from wild pupae in the laboratory showed a peak during the afternoon (1400–1730 hr.) which was not affected by light or gamma-radiation. In the field, eclosion occurred primarily between 15° and 27°C. and was apparently inhibited by higher and lower temperatures. Relative humidity did not appear to be involved in the timing of emergence.