bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on yams attacked by the yam beetle Heteroligus meles (Billb.) (Col., Dynastidae)
Authors: Gregory J. L. 
Published: July 2009

Several species of Dynastid beetles are serious pests of yam (Dioscorea) in Nigeria, the adults attacking the setts and new tubers underground. The base of the yam vine and the roots are not generally damaged. The most important species is Heteroligus meles (Billb.).H. meles does not breed in the yam fields, and the adults fly to them from breeding grounds that are distinct, and to which they return later.The cultivation and growth of the yam plant in Nigeria are briefly described. Small tubers, or cut pieces of tubers (setts) are planted. The earlier the date of planting and of emergence of the vine from the soil, the heavier the vine and the new tuber.An account is given of observations on the infestation, in relation to crop growth, of a plot of yellow yams (D. cayenensis) planted near Benin, in Western Nigeria on 29th March 1958.Adults of H. meles were taken, from 3rd April to 26th June and again from 8th to 21st November, between 7 and 9 p.m., at a light-trap placed at a distance of ¼ mile from the plot.Beetles entered the soil of yam hills within six inches of the vine, usually before 7 a.m., on mornings following evening flights, the entry holes usually being identifiable. The first vines were seen in the experimental plot on 19th April. Beetles did not enter a yam hill unless the vine had emerged.The longer the exposure to flying beetles, the more likely were plants to be attacked, and bigger vines attracted more beetles than did smaller ones. Later planting decreased beetle damage, but a lower yield resulted.At first the beetles fed on the sett, making and increasing the size of fewer lesions than later on the new yam. About the time that the flying period ended, the setts were starting to rot, and the beetles left the immediate vicinity of the yam plant, as no acceptable food was available. Most moved deeper into the soil, but a few left the plant altogether and flew away. After the new tubers had begun to develop, the beetles returned in early August from their positions deeper in the soil to feed on them, constantly making new lesions, more numerous but smaller than those made in the setts, averaging about 4 g. of yam eaten.During late August and again in late September, a few beetles moved underground from the original plants attacked to others. In mid-November, the beetles left the yam fields altogether, presumably returning to the breeding area.The reasons why the beetles fly away from the yam fields remain uncertain, but they may include the seasonal decline in rainfall, the maturation of the yam tuber and the development of the gonads.Factors that can affect the rate of attack are the dates of planting and harvesting in relation to the period during which the beetles fly, the method of cultivation and the variety of yam planted.
Problems in assessing insecticidal control of Amnemus species (Coleoptera. Curculionidae) in clover pastures of north coastal New South Wales
Authors: Braithwaite B. M. , Jane Annette 
Published: July 2009

Results are presented of 15 experiments made in north coastal districts of New South Wales from 1957 to 1961 with insecticides against the weevils Amnemus quadrituberculatus (Boh.) and A. superciliaris (Pasc.), the larvae of which have been reported as pests attacking the roots of clover (Trifolium repents, T. pratense and T. subterraneum) there. The adults live above ground, and single surface applications of insecticides were made to pastures in the form of dusts, granules or dilutions of emulsifiable concentrates in January, when maximum numbers of weevils were present and before significant oviposition had taken place. Insecticidal control was assessed by soil sampling for larvae in July–August, during the following winter. Pasture cuts were made in an attempt to assess the effect of treatments on the yield of clover.Dieldrin at rates of 2 and 4 lb. per acre gave near eradication of Amnemus for one year, and satisfactory control was obtained with 1 lb. per acre. Aldrin, endosulfan (Thiodan) and BHC were less effective, and limited tests with heptachlor suggested that it was inferior to dieldrin. The scanty results available suggest that dieldrin is effective against Amnemus for only one year, but it is doubtful if annual applications are warranted. Owing to the patchy distribution of clover in the pastures, only one experiment showed an increased yield of clover associated with the reduction in numbers of larvae of Amnemus brought about by the application of 1 lb. dieldrin per acre. Similarly, poor persistence of clover on all plots prevented assessment of any residual effect on yield in the second year.No method was found by which accurate estimates could be made of the density and distribution of adults of Amnemus in pastures to which insecticides were to be applied. Treatments, therefore, were replicated more frequently than was needed statistically in order to ensure that measurable levels of larval infestation were present at sufficient sites.Small plots (500–700 sq. ft.) proved of little value, and this is attributed not only to contamination of control plots but possibly also to the death of weevils that moved from untreated into treated plots. Large plots (13,000–21,000 sq. ft.) gave the most consistent results in assessment of insecticides.Control of Amnemus did not increase the productivity or persistence of clover, and it is concluded that any benefits from control are unlikely to be significant unless other factors, such as competition from grasses, drought, floods, nematodes and diseases of clover, which affected the density and persistence of clover in these experiments, are not limiting.
Toxicology and genetics of two types of insecticide resistance in Chrysomyia Putoria (Wied.)
Authors: Busvine J. R. , Bell J. D. , Guneidy A. M. 
Published: July 2009

Resistant and normal colonies of the blowfly Chrysomyia putoria (Wied.) were obtained from the Congo and cultured in London. By selection and inbreeding, sub-colonies homogeneous for resistance to (a) the BHC/dieldrin group of chlorinated insecticides and (b) malathion, were obtained. Homogeneous resistant colonies were markedly less fertile and were difficult to perpetuate.Toxicological investigations of the BHC/dieldrin-resistant colony revealed a characteristic resistance spectrum similar to that of six other insect species. Genetical experiments with the BHC/dieldrin-resistant strain indicated inheritance by a single gene pair, intermediate in dominance, very similar to that reported in nine other insect species.Toxicological investigations of the malathion-resistant colony, including tests with 19 organophosphorus insecticides, showed a resistance largely specific to malathion and malaoxon. This was rather similar to malathion-resistant strains of two other species, for which data were available. It is known that the toxic action of malathion on mammals can be potentiated by prior treatment with small doses of certain organophosphorus compounds, which inhibit an aliesterase that detoxifies malathion by carboxylic hydrolysis, and furthermore that potentiation has been found in malathion-resistant strains of the house-fly, Musca domestica L. Accordingly, the phenomenon was investigated in C. putoria by adding non-lethal amounts of EPN or tri-o-cresyl phosphate (TOCP) to malathion. It was found that specific malathion-resistance was virtually abolished by this means, a result that suggests that such resistance in this species depends on a carboxyesterase. Genetical experiments with the malathion-resistant strain indicated inheritance by a single gene pair, with nearly complete dominance, similar to that in three other insect species.It is concluded that both types of resistance in C. putoria have much in common with those occurring in analogous strains of other insect species.
Cattle-tick control in Northern Nigeria: a field study of BHC, Sevin, toxaphene and ronnel used as sprays
Authors: Thorpe R. J. , Walker P. 
Published: July 2009

A field study was made of the effects of γ BHC, Sevin, toxaphene and ronnel (fenchlorphos) used as sprays on the numbers of ticks infesting cattle at Shika stockfarm in the Northern Guinea Savannah zone of Nigeria.The tick population included Boophilus annulatus (Say), B. decoloratus (Koch), Amblyomma variegatum (F.), Hyalomma truncatum Koch and Rhipiccphalus simus simus Koch, and its distribution on the host is described.Significance tests of treatment difference were carried out for initial kill and reinfestation rate. In both dry- and wet-season trials toxaphene proved to be the most effective ixodicide. A satisfactory degree of control was given by γ BHC but not by Sevin or ronnel.It is concluded that spraying at 21- and 7-day intervals during the dry and wet seasons, respectively, with either toxaphene or γ BHC will maintain a stable, satisfactory level of tick parasitism and premunity to tick-borne diseases in the herd.
The control of the sources of virus yellows of sugar-beet
Authors: Ribbands C. R. 
Published: July 2009

The means whereby sugar-beet yellows viruses and their predominant vector,Myzus persicac(Sulz.), overwinter in Britain are reviewed.M. persicaeoverwinters mainly on cultivated secondary host plants that are not associated with the viruses: the viruses overwinter principally in the mangold and sugar-beet seed crops, which are the main source of infection in the following summer; mangold clamps may be a minor source and weeds seem unimportant.Despite autumn certification of first-year sugar-beet seed crops, visible infection within them in the following June is never negligible, and rapid spread of virus within these crops during their second year can cause a high proportion of the plants therein to be infective, although still symptomless. The many aphids that may leave these crops and the uncertified seed crops are an important source of infection for the root crop.It is suggested as a new control measure that seed crops of beet and mangolds should be grown in Britain in alternate years only. Consideration of the low frequencies of winds of a speed and direction suitable for carrying viruliferous aphids from Continental beet-growing areas to Britain, and of the low incidence of virus yellows in areas of Britain that are free of seed crops and comparable, in distance and direction relative to the main British beet-growing areas, with those of the latter in relation to the Continent, suggests that the effectiveness of the proposed measure is unlikely to be nullified by intrusion of infected aphids from the Continent.
Laboratory studies on dispersion behaviour of adult beetles in grain. IV.—The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera, Bostrychidae)
Authors: Surtees Gordon 
Published: July 2009

Dispersion behaviour of the adult of the lesser grain borer, Rhyzopertlia dominica (F.), 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 effects of population density, temperature and moisture content of the grain on numbers at the surface were studied by using groups of insects in 500 g. wheat, and on dispersion in the vertical plane by confining beetles within a monogranular plate of wheat held between vertical glass sheets, through which the positions of individuals could be observed.In grain at 25°C. and 14 per cent, moisture content (70 per cent. R.H.), the proportion of a group on the surface averaged approximately six per cent, for densities of 5–100 insects in 500 g., and the proportion was higher than in grain at the same temperature and 9 or 17 per cent, moisture, or at the same moisture content and 15 or 35°C.In grain of 14 per cent, moisture content, the level of individual locomotory activity increased from 15 to 35°C. At 25°C., locomotory activity was depressed in grain of 9 and 14 as compared with 17 per cent, moisture content. These results are discussed in relation to group formation and dispersal of R. dominica and its contact with Sitophilus granarius (L.) if both species are present in the same grain bulk.
Biology and ecology of the garden chafer,Phyllopertha horticola(L.). VIII.—Temperature and larval growth
Authors: Laughlin Roger 
Published: July 2009

Fecundity in the garden chafer,phyllopertha horticola(L.), is extremely variable. Fecundity depends entirely on reserves laid down by the larva.Previous work in Britain showed that (a) early larval feeding periods in the field produce heavy pupae; (b) in an experiment comparing early with late-hatched larvae, the heavier diapause larvae developed from the early batch; (c) in the field, the earliest larvae to enter diapause were the heaviest.Further data (hitherto unpublished) showed that larvae reared at 25°C. entered diapause heavier than larvae reared at field temperature, although mortality was high. The above data also indicated that time of entry into diapause was fixed and unaffected by temperature.A repeat of the field experiment (b) showed the same result and also showed how a population of feeding third-instar larvae can be destroyed by frost while larvae in diapause deeper in the soil are unaffected. Thus a late season produces light larvae and a high risk of death before diapause.Observations on larvae kept at constant temperatures (12, 16 and 18°C.) showed that the temperature threshold of development is about 12°C. in the first instar but is lower in succeeding stages; the length of the first and the second instars decreases with rise in temperature; high temperature probably produces larger larvae by the end of the second instar, but the effect was small and none at all was detected at the first moult.The length of the third-instar feeding period is not affected by temperature in the range 12–20°C. Kate of growth (increase in weight) increases with temperature. The higher temperatures (perhaps as a result) produce heavy diapause larvae and pupae in both sexes. Entry into diapause is hindered at 20°C. The weight of a larva at the second moult is positively correlated with its diapause weight.It is suggested that the temperature effects described can be most simply explained by postulating the existence of differential temperature coefficients for the various growth processes.
Laboratory assessment of the toxicity of field-weathered deposits of insecticides to larvae of the codling moth, Cydia pomonella (L.)
Authors: Gratwick M. 
Published: July 2009

The toxicity of naturally weathered deposits of 21 chemicals to larvae of the codling moth, Cydia pomonella (L.), was assessed by spraying apple trees in the orchard and testing samples of the fruit picked at various intervals after treatment. Each apple was placed in a separate glass container with one first-instar larva from a laboratory culture, and larval mortality and damage to the fruit (defined as removal of a portion of the skin) were recorded after three days in a constant environment.The site of entry of the larvae was shown to vary with fruit size, calyx entries decreasing and side entries increasing with increase in the surface area of the fruit.The relationship between larvicidal activity and age of the spray deposit for periods up to ten weeks after spraying is illustrated graphically; data are presented for fruit damage caused by larvae applied one and three weeks after spraying.On the basis of larval mortality and fruit damage recorded in tests on deposits up to three weeks after application, a spray containing 0·1 per cent, carbaryl was the most effective, followed by 0·05 per cent, fenthion, while Bayer 5024, Zectran, DDT, DDD (all at 0·l per cent.) and 0·04 per cent, azinphos (as the methyl or ethyl homologue) were only slightly less effective. Deposits from 0·1 per cent. Kepone, 0·02 per cent, diazinon, 0·11 per cent, malathion, 0·01 per cent, parathion and 0·05 per cent, carbophenothion, dimethoate and ethion also caused 90–100 per cent, mortality when fresh, but were less persistent. Fresh deposits from 0·1 per cent, endosulfan, 0·04 per cent, dioxathion, 0·05 per cent, phenkapton, 0·02 per cent, phosphamidon, 0·2 per cent, lead arsenate and 0·6 per cent, ryania only killed 50–88 per cent, of the larvae, and their residual toxicity was proportionately low.Heavy rain soon after spraying caused a large reduction in deposits from wettable powders but the accompanying reduction in larvicidal activity was shown to be greater in the case of carbaryl than for DDT or DDD.
Insect reinfestation problems in fumigated maize on the Kenya coast
Authors: Ashman F. 
Published: July 2009

Bagged maize stored in large stacks on the Kenya coast is subject to reinvasion by stored-products pests following successful fumigation with methylbromide, and treatment of the stack surfaces with insecticidal sprays has been unsatisfactory in preventing reinfestation.Further tests are described of different methods of applying insecticides to small experimental stacks, each composed of ten 200-lb. bags of maize, exposed within a warehouse, after fumigation, to reinfestation from a large bulk of maize heavily infested with Tribolium castaneum (Hbst.). Populations of adults and pre-adult stages of T. castaneum were recorded from samples of grain obtained by a sampling spear from each bag at intervals.In the first of two experiments, single applications of malathion in a spray at 100 and 150 mg. per sq. ft. to the entire external surface of each bag during the construction of the stack did not give good control of reinfestation in the six months after fumigation, but were not significantly worse, respectively, than a dust containing 1 per cent. lindane similarly applied to the upper surface of each bag and, four weeks later, to the outside of the stack at the rates of 3 and 6 oz. per bag. When the malathion treatments were followed by 24, 12 or 8 applications, at intervals of 1, 2 or 3 weeks, respectively, of sprays containing malathion to give 100 and 150 mg. per sq. ft. over the whole external surface of the stack, good control of T. castaneum was obtained with all treatments.Mean residues of malathion in the outer inch of maize in the bags six months after the start of the experiment varied from 3 to about 19 p.p.m., according to treatment, suggesting that little penetrated through the bag wall and that after thorough mixing of the grain before use the malathion content would not exceed the permissible limit.In the second experiment, an admixture of malathion dust with the maize before bagging to give 8 p.p.m. active ingredient gave almost complete control of larvae and pupae, and application of 3 oz. 0·5 per cent, malathion dust, or a spray affording 400 mg. malathion per sq. ft., to the upper surface of each bag during stacking gave highly significant reductions in numbers of T. castaneum in the pre-adult stages. The last of these treatments, followed, after fumigation, by malathion applied in a spray at 150 mg. per sq. ft. every three weeks to the external surfaces of the stack, is recommended for large-scale trial.
Genetical studies on dieldrin-resistance in Musca domestica L. and Lucilia cuprina (Wied.)
Authors: Guneidy A. M. , Busvine J. R. 
Published: July 2009

The mode of inheritance of dieldrin-resistance in house-flies, Musca domestica L., was investigated by crossing experiments, using a selected, inbred resistant colony (R) and a normally susceptible one (N). Levels of susceptibility in both colonies and in various hybrids derived from them were determined by treating batches of flies with different concentrations of dieldrin by topical application.Reciprocal crosses gave closely similar results, which were pooled. Results obtained with males and females were analogous, but were treated separately. The F1 hybrids were intermediate in resistance and the F2 generation segregated into susceptible, hybrid and resistant individuals in the ratio 1:2:1. The F1 generation back-crossed to either parental strain gave 1:1 segregation, corresponding to NN + NR or NR + RR. After killing the more dieldrin-susceptible forms in each case, the remaining males were back-crossed again. The second back-cross to normal gave a further 1:1 segregation of susceptibles and hybrids. The second back-cross to resistant now gave all homozygous resistant forms.These results strongly indicate monofactorial inheritance.Two highly dieldrin-resistant colonies of the sheep blowfly Lucilia cuprina (Wied.) had been colonised, one from Australia and one from South Africa. These were crossed and the progeny maintained to the F2 generation. Tests with dieldrin on the F1 and F2 generations gave results resembling those obtained with the parents. Since there was no appearance of susceptible or hybrid forms in the F2, it is concluded that the genes in the two colonies occur on the same chromosome and are either allelic (possibly identical) or very closely linked.
A dipping technique for selecting house-flies, Musca domestica L., for resistance to insecticides
Authors: Sawicki R. M. , Farnham A. W. 
Published: July 2009

A dipping technique for exposing large numbers of house-flies (Musca domestica L.) to measured doses of insecticide is described. It is suitable for selecting resistant populations and, while giving consistent results, is more rapid than other techniques used for this purpose.Up to 2,000 flies of both sexes, less than 24 hr. old, are immersed for three minutes in 100 ml. of a 70 per cent, mixture of acetone and water containing the required concentration of insecticide, using a 9-cm. sintered glass Büchner funnel as the immersion chamber. The liquid is then removed by suction, the sides of the funnel are wiped with filter paper, and the flies are allowed to drain for three minutes; they are then transferred in small batches to plastic recovery chambers containing food. Mortality is recorded next day, and the survivors are released into breeding cages.Experiments showed that immersion for three minutes in 70 per cent, acetone was virtually harmless to the flies and that the amount of insecticide deposited on individual flies was reasonably uniform (coefficient of variation about 20%). Batches of 2,000 flies, but not more, could be treated at one time.When the dipping technique was compared with topical application of measured drops of insecticide, using a susceptible strain of house-flies and two other strains that were resistant to DDT and diazinon, dipping gave steeper log-probit regression lines than topical application, and the LD50's and resistance factors of the resistant strains were smaller. With flies resistant to DDT, dipping gave straight regression lines whereas topical application gave compound lines.
The occurrence of two strains ofBrontispa longissima(Gestro) (Col., Hispidae) based on resistance or non-resistance to the parasiteTetrastichus brontispae(Ferrière) (Hym., Eulophidae) in Java
Authors: Tjien-Mo Tjoa 
Published: July 2009

In Java,Brontispa longissima(Gestro) (Col., Hispidae) is represented by chr. var.javanaWeise and in South Sulawesi (South Celebes) by chr. var.selebensisGestro. The endoparasiteTetrastichus brontispae(Ferriére) (Hym., Eulophidae) attacks both chr. var.javanaandselebensis.However, in Java, there are two distinct strains of chr. var.javana. In one strain (A-strain) the parasite completes its development normally but in the other (B-strain) the parasites usually die in the larval stage. The areas where each strain occurs have been demarcated.In laboratory studies at Bogor during 1958 it was established that the lifecycles of the A- and B-strains were similar.T. brontispaecompleted its development from egg to adult in 15 to 21 days (16 on average) in A-hosts but died in the larval stage in B-hosts within three to four days. In a few instances parasites in B-hosts were able to complete their development, but generally the host died a few days after the death of the parasites.In the laboratory, adult parasites attacked B-hosts as readily as A-hosts, although the former were not suitable for parasite development. Phagocytosis by encapsulation or melanisation was occasionally encountered but was not the usual cause of the death of the parasites.