bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) sex Pheromone on behaviour of males in field and laboratory
Authors: Langley P. A. , Huyton P. M. , Carlson D. A. , Schwarz M.
Published: July 2009

More adult males of Glossina morsitans morsitans Westw. were caught with hand nets in Tanzania from a man-carried dark screen baited with surrogate female decoys impregnated with synthetic 15,19,23-trimethyl-heptatriacontane (the G. m. morsitans sex pheromone) than from a screen bearing unimpregnated decoys or from a screen alone. A similar pattern was obtained with G. pallidipes Aust., but the variations in numbers of both species caught within and between fly-round sectors were large. Although many G. m. morsitans males attracted to the screens visually were seen to engage in copulatory activity with pheromone-impregnated decoys, none of the G. pallidipes so attracted was seen to do so. It is therefore concluded that catches of G. m. morsitans were not improved by the presence of pheromone-baited decoys on visually attractive screens. Copulatory behaviour was frequently interrupted by other flies and/or the flies flew off as soon as the screen ceased to move. Of the G. m. morsitans males attracted to a baited screen on the back of a slowly moving vehicle, 51% were seen to have alighted on the impregnated decoys and 42% were engaged in copulatory behaviour with the decoys immediately after the vehicle stopped. Copulatory responses of wild male G. m. morsitans to pheromone-impregnated decoys in glass tubes approximated those of laboratory-reared males only after confinement for several hours at low light intensity. Contamination of laboratory-reared male G. m. morsitans with synthetic pheromone elicited prolonged male:male copulatory behaviour. Prospects for the use of the G. m. morsitans sex pheromone in population studies or control programmes are discussed.
Comparative injuriousness of Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Pyralidae) on grain sorghum
Authors: van den Berg J. , Van Rensburg J.B.J. , Pringle K.L.
Published: July 2009

The comparative influence of Busseola fusca (Fuller) and Chilo partellus (Swinhoe), both as separate and mixed populations, on growth and yield of grain sorghum was investigated in a field experiment, using an artificial infestation in cages. C. partellus was more injurious than B. fusca as indicated by whorl damage, stalk injury and yield loss. In the case of mixed populations, dispersion of larvae and damage were independent of B. fusca numbers. A regression equation, Logit Y = 0.24 + 2.06 logit x, relating visible plant damage to yield loss was determined. Control strategies in the case of mixed stem borer populations should be directed against C. partellus.
A new species of gall midge (Diptera: Cecidomyiidae) attacking mango foliage in Guam, with observations on its pest status and biology
Authors: Harris K.M. , Schreiner I.H.
Published: July 2009

A new species of gall midge,Procontarinia schreineriHarris, which attacks mango foliage in Guam, is described and the results of field observations on its pest status, biology and population fluctuations are reported. Eggs are laid on young mango leaves and larvae, which develop rapidly over about 5 days, induce blister galls before leaving to pupate. Secondary damage to infested foliage is caused by the fungusColletotrichum gloeosporioides, which invades damaged leaf tissue and causes mango anthracnose disease.P. schreineripopulation fluctuations on mangoes were assessed at four localities on Guam over three years by counting the numbers of galls. It was concluded that the main factors affecting populations were rainfall and location. More galls were present during rainy periods, possibly because high humidity improves larval and pupal survival. Gall populations were generally low and unlikely to have direct effects on fruit yields but the introduction of new improved varieties of mango might increase susceptibility to damage. In addition, old galls on damaged leaves may provide reservoirs of anthracnose inoculum.
Simulation of instability in genetic sexing strains: effects of wild-type contamination in association with other biological parameters
Authors: Busch-Petersen E. , Baumgartner H.
Published: July 2009

Genetic methods to eliminate females prior to releasing sexually sterilized males in sterile insect technique programmes generally involve the translocation onto the Y chromosome of a readily selectable gene (here designated F). However, such strains often show instability with regard to sexual dimorphism. Concerted attempts to determine the most probable causes of such instability have rarely been successful, and appropriate countermeasures have generally not been implemented. We have developed a computer model which simulates the progression of instability in such strains. Here we simulate the effects of contamination in association with a range of genetic and biological parameters and assess the patterns and rates of progression of the ensuing instability. A single event of contamination alone was found to contribute relatively little to the progression of instability and invariably resulted in an equilibrium within the population. However, strong effects were produced by reduced fitness and mating competitiveness of both the f/f genotype and the translocation carriers, a reduction in the parameters involving the f/f genotype resulting in the virtual elimination of f/f, while a reduction in the translocation parameters had the opposite effect of virtually eliminating the F/ – phenotype. The sex ratio was affected only by a change in the relative fitness of the f/f genotype and the translocation. Several characteristic patterns contributed to distinguish clearly the effects of contamination from those of male recombination in unstable genetic sexing strains. With such knowledge appropriate measures may be taken to counter or alleviate the effects of instability in mass reared genetic sexing strains.
Incubation and overwintering in the egg stage of the African migratory locust,Locusta migratoria migratorioides(Orthoptera: Acrididae), on the highveld of South Africa
Authors: Price R.E. , Brown H.D.
Published: July 2009

Incubation of eggs of the African migratory locust,Locusta migratoria migratorioides(Reiche & Fairmaire), was examined in the Orange Free State (OFS) highveld of South Africa where the locust is a recurring pest of cereal crops. A minimum incubation time of 16±SE 0.97 d was recorded in summer and this progressively increased through autumn as temperatures declined. Eggs laid in autumn overwintered for 140±2.63 d until spring, when rising temperatures initiated hatching. Controlled laboratory studies established that the threshold for egg development was in the region of 15.6°C and that eggs required 5268 degree-hours to complete their development. Analysis of hourly soil temperature records, measured at egg pod depth in the field, showed that temperatures first dropped below this critical temperature threshold during mid-April, after which eggs became quiescent and overwintered until spring. There was no evidence of diapause in the field and overwintering eggs exhibited a wide range of embryonic development. Quiescence during winter on the OFS highveld was therefore a simple temperature-induced response. This is the first record of prolonged overwintering in the egg stage of the migratory locust in Africa.
Field density estimates of Heliothis virescens (Lepidoptera: Noctuidae) from catches in sex pheromone-baited traps
Authors: Witz J.A. , Lopez J.D. , Latheef M.A.
Published: July 2009

The number of male tobacco budworm, Heliothis virescens (Fabricius), trapped on a daily basis in pheromone traps in individual cotton fields was compared to male and female adult densities measured by nocturnal field sampling. The decline of trap efficiency with increasing female density was demonstrated. A simple relationship for estimating H. virescens male density from the numbers trapped was derived as P♂ = (E2/13)2, where P♂ is density and E2 is the two-day exponential average of number trapped. The standard error for the regression translates to an accuracy ratio of 2:1. The results compare favourably with previous research using mark-release-recapture methodology. Application of the formula is discussed.
Allozyme variation and an estimate of the inbreeding coefficient in the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae)
Authors: Borsa Philippe , Gingerich D. Pierre
Published: July 2009

Seven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.
Adult resting sites as a target for chemical control of the cocoa pod borer, Conopomorpha cramerella (Lepidoptera: Gracillariidae), in Malaysia
Authors: Day Roger K. , Mumford John D. , Hing Ho Shui
Published: July 2009

The daytime resting sites of adult Conopomorpha cramerella (Snellen), a serious pest of cocoa in south-east Asia, were identified as a possible target to which insecticide could be selectively applied. Field observations were made on 126 resting moths in a cocoa plantation in East Malaysia. All moths were found on the undersides of branches 45° or less from horizontal, and 1·5 cm or more in diameter; 90% were found in the lower half of trees. A field trial was conducted in which 25 ppm deltamethrin was applied with knapsack sprayers to these sites. Five applications were made at ten day intervals, each crop season (6 months), over a two year period. Mean estimated losses in the sprayed area were 12.1 to 33.7 percentage points lower than in the control area, giving an estimated net benefit of up to RM978 ha in one season, assuming a cocoa price of RM4000 per tonne. Losses in the sprayed area still ranged from 7.0% to 43·1% and did not decline over successive seasons. There was some evidence for immigration into the sprayed area, but it is suggested the rapid recovery of populations following spraying is also due to the high potential rate of increase of the insect in susceptible cocoa varieties. In susceptible cocoa varieties control is always likely to be difficult, but in less susceptible varieties, and with well maintained trees, chemical control by selective application to adult resting sites can be a practical component of integrated control.
Impact of the soil insects African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae) and Whitefringed weevil, Graphognathus leucoloma (Coleoptera: Curculionidae), on potatoes and effects of soil insecticide treatments in south-western Australia
Authors: Matthiessen J.N. , Learmonth S.E.
Published: July 2009

Populations of the soil insects African black beetle, Heteronychus arator (Fabricius), and whitefringed weevil, Graphognathus leucoloma (Boheman), and the damage caused to potato crops in south-western Australia were measured with and without the insecticide chlorpyrifos incorporated into the soil prior to planting. Low populations of both insects were highly damaging. Destruction of stems by H. arator reduced tuber yield and both species damaged tubers from the time of their formation. Tuber damage increased with time because both insect species on average damaged multiple tubers and caused multiple attacks on tubers. Growth of G. leucoloma larvae caused increased abundance of the more damaging later instars in spring. The insecticide reduced resident H. arator abundance and hence damage to newly-emerging potato stems in summer, but had less effect on reducing attacks on tubers in summer crops because adult beetles flew into some crops during growth. Exceptionally high tuber damage per H. arator adult in winter crops was ascribed to enhanced activity during its spring breeding season. The insecticide was inconsistent in reducing the abundance of G. leucoloma larvae. Insecticidal effects were greatest near the soil surface, resulting in an increase in the relative proportion of both insects deeper in the soil. Since a greater proportion of the tubers occurred there, the resulting greater potential for the insects to cause tuber damage tended to outweigh reduction in their abundance.
Adaptive significance of changes in morph production during the transition from parthenogenetic to sexual reproduction in the aphid Rhopalosiphum padi (Homoptera: Aphididae)
Authors: Austin A.B.M. , Tatchell G.M. , Harrington R. , Bale J.S.
Published: July 2009

Many aphid species have life cycles which alternate between asexual reproduction during spring and summer and sexual reproduction in autumn. This paper describes the sequences of morphs produced by clones of Rhopalosiphum padi (Linnaeus) in response to a range of photoperiods and temperatures in the laboratory, and under semi-natural conditions at the time of year when the transition from parthenogenetic to sexual reproduction occurs. By using similarities in the order in which the various morphs were born, clones of R. padi were found to produce eight progeny sequence types. A clone of R. padi will produce these sequence types sequentially as it changes from parthenogenetic to fully sexual reproduction. The progeny sequence produced by clones under conditions corresponding to those of spring and summer consist of parthenogenetic females only. During late summer, production of parthenogenetic females is followed by males. Later in the year, a clone produces progeny sequences consisting of parthenogenetic females, gynoparae and males. The asexual phase of reproduction is terminated in late autumn when only gynoparae and males are born. A minority of clones terminate parthenogenetic reproduction by producing only gynoparae. The function of these changes in progeny sequence in maximizing the reproductive success of a clone of R. padi is discussed.
The foraging behaviour of redlegged earth mite,Halotydeus destructor(Acarina: Penthaleidae), in an annual subterranean clover pasture
Authors: Gaull K.R. , Ridsdill-Smith T.J.
Published: July 2009

The foraging behaviour of the redlegged earth mite,Halotydeus destructor(Tucker), in annual pasture was documented and the relative numbers of individuals foraging on subterranean clover,Trifolium subterraneum(Leguminosae), capeweed,Arctotheca calendula(Compositae) and grasses (mainlyLolium rigidum(Gramineae)), estimated in winter and spring in south-western Australia. The main feature ofH. destructorforaging behaviour was the presence of aggregations ranging in size from 3–36 individuals on the adaxial surfaces of the upper canopy of the pasture. Most aggregating individuals were feeding, while most solitary and paired individuals were searching. There was no evidence that individuals aggregated for reproductive behaviour; the adult sex ratio was similar to that of the population even though immatures were under-represented in aggregations. During winter the distribution of numbers ofH. destructoron subclover, capeweed and grasses in the upper canopy of pasture was similar to the estimated ground cover of these plant species. However, individuals showed host-plant selection for subclover when feeding. During spring, when the pasture plants were flowering, there were moreH. destructorin capeweed flowers than in aggregations on subclover foliage. The capeweed flowers were shown to enhance the rate ofH. destructorreproduction in a laboratory experiment. MostH. destructorwere on or near the soil surface, with 10% at any one time on the upper canopy of the pasture.H. destructoris polyphagous, and behaved in pasture as a selective opportunist feeder.
Toxic effects of leaves ofRicinus communis(Euphorbiaceae) to laboratory nests ofAtta sexdens rubropilosa(Hymenoptera: Formicidae)
Authors: Hebling Maria José A. , Maroti Paulo Sérgio , Bueno Odair Correa , da Silva Osvaldo Aulino , Pagnocca Fernando Carlos
Published: July 2009

Laboratory nests of the leaf-cutting antAtta sexdens rubropilosaForel fed daily with leaves ofRicinus communisshowed a gradual decrease in fungal garden volume, a higher ant mortality rate, and fungal garden extinction after 6 weeks. The mean oxygen consumption rate of these ants was higher than that of control ants collected from nests fed with leaves ofEucalyptus alba(Myrtaceae) suggesting one or more components of the leaves ofR. communishad a direct physiological effect on the ants, in addition to inhibiting fungal garden growth.
Examination of the involvement of mechanical strength in antixenotic resistance of subterranean clover cotyledons to the redlegged earth mite (Halotydeus destructor) (Acarina: Penthaleidae)
Authors: Jiang Y. , Ridsdill-Smith T.J.
Published: July 2009

Resistance involving penetrability of cotyledons of subterranean clover Trifolium subterraneum (Leguminosae) by the redlegged earth mite, Halotydeus destructor Tucker, was examined in this study using several approaches. Values of penetrability, presented as mechanical strength measured with a penetrometer with a tubulated probe, of cotyledons tested 11–13 days after seeding, from nine varieties of two subspecies of subterranean clover (T. subterraneum subsp. yanninicum and subsp. brachycalicinum) were negatively correlated with feeding damage caused by H. destructor in both 3 h pairwise choice tests in a Petri dish with detached cotyledons, and in 2 week multiple choice tests in containers with seedlings. Simulation tests with different artificial membranes (Parafilm and Gladwrap) making up sachets, containing 5% glucose as a feeding stimulant, indicated that within 3 h H. destructor preferred membranes with lower strength. Field-collected young adults had significantly higher physical fitness to feed and/or gather on the artificial membrane sachet containing 5% glucose, than those from the laboratory culture, when the sachet was compared with cotyledons of either resistant (DGI007) or susceptible (Dalkeith) varieties in the choice tests. Electron microscopic observations of mite infested cotyledons of the resistant variety (DGI007) reveal that upper epidermal cell walls around penetration holes are bent inwards. Anticlinal cell walls of palisade cells appear buckled following attack by H. destructor. The results from these studies were taken as further evidence for the involvement of mechanical factors in antixenotic resistance of subterranean clover cotyledons to H. destructor.
Evaluation of sticky panels to monitor populations of Glossina austeni (Diptera: Glossinidae) on Unguja island of Zanzibar
Authors: Vreysen Marc J.B. , Khamis Issa S. , Vloedt André M.V. Van der
Published: July 2009

Monitoring of Glossina austeni Newstead populations in the forested areas of Unguja island of Zanzibar has since November 1990 routinely been carried out with the sticky panel trap because commonly used tsetse traps (Biconical, Epsilon, F3) have proved to be unsuccessful in catching G. austeni. Initial studies on the catching ability of various types of sticky panels for G. austeni indicated that the monopanel was as efficient in catching flies as the 3-dimensional version and the smaller legpanel. No significant differences in catch rate and sex ratio were observed with monopanels in various colours and colour combinations. Legpanels coloured white on one panel side and blue on the other side caught significantly more flies compared with other colour combinations, but female flies were under-sampled (32%). The type of sticky material applied on the panel influenced significantly the catch rate and female ratio. During long-term trapping with baby blue and white monopanels, females were under-sampled (38–46%) except when polyisobutyleneLMW was used as sticky material. Analysis of the age composition of the sampled G. austeni females revealed that tenerals and nulliparous were well represented (11–24%). More than 20% of the trapped females were older flies, i.e. females with four or more ovulations, but this percentage dropped to 10% when Tanglefoot was used as sticky material.
Investigations of the chemical control of insect pests of cotton in central Africa. I.—Laboratory rearing methods and tests of insecticides by application to bollworm eggs
Authors: Matthews G. A.
Published: July 2009

Cotton in Central Africa is subject to attack by numerous insect pests, and this has limited production. The pests include Diparopsis castanea Hmps., Heliothis armigera (Hb.), Earias spp. and Dysdercus spp. Methods of rearing these insects in the laboratory are described, preparatory to testing insecticides for their control. By means of an egg-dipping technique, the susceptibility of first-instar larvae of Diparopsis castanea to a wide range of insecticides was determined, and that of similar larvae of E. biplaga Wlk. to a smaller range. The most effective were methyl-parathion, carbaryl, menthyl-demeton, parathion, methiocarb, Zectran, isobenzan, endosulfan, BHC, endrin and phosphamidon. DDT was more effective against Earias than against Diparopsis, and toxaphene was relatively ineffective against both. Aftertakiing the mammalian toxicity of the insecticides and certain other factors into consideration, carbaryl, endosulfan, endrin and DDT were selected for further evaluation in the laboratory and the field.
RearingMamestra brassicae(L.) on semi-synthetic diets
Authors: David W. A. L. , Gardiner B. O. C.
Published: July 2009

A diet previously described for rearingPieris brassicae(L.) was found to be very successful for rearingMamestra brassicae(L.). Less than 5 per cent. of the pupae that formed entered diapause. The larvae can be much more quickly counted, examined and looked after when kept on the diet than when kept on cabbage leaves.
Feeding by Distantiella theobroma (Dist.) (Heteroptera, Miridae) on Cocoa. I.—The effects of water stress in the plant
Authors: Gibbs D. G. , Pickett A. D.
Published: July 2009

Data were obtained on survival and development of larvae of Distantiella theobroma (Dist.) on cocoa seedlings maintained under three water régimes, high (HW), intermediate (IW) and low (LW). Recorda were taken of plant growth and damage by feeding. The water régimes of some plants were reversed in the latter part to the experiment.

Larvae soon completed development on HW plants, but on LW plants a large number died, possibly because they were unable to take up fluid fast enough to offset loss by evaporation. There was intermediate mortality on IW plants.

Larvae took longer to develop on IW than on HW plants, probably because they imbibed nutrients at a reduced rate.

More larvae survived on LW plants that were regenerating after increase in water status than on plants that had received abundant water continuously. They fed mainly on the old wood and very little on the soft regenerative shoots, so were apparently favoured by some change in the peripheral tissues of the main stem.

On HW plants, nearly all feeding took place on woody or partially hardened tissue; newly flushing tissue was not fed on if it was growing normally. On IW plants, the expansion of new terminal leaves was often slow, and these tissues were then attacked by young larvae. This happened much more on LW plants, where the apical region was killed by persistent feeding. On all plants larvae older than second instar fed only on hard tissues.

Later effects of feeding were splitting of the wood where lesions had been made and sometimes the development of fungal infecdtions. The most severe infections occurred when the upper part of the old stem died back on LW plants that were regenerating after increase in water status.
The identity of the palm kernel borer in Nigeria, with systematic notes on the genusPachymerusThunberg (Coleoptera: Bruchidae)
Authors: Prevett P. F.
Published: July 2009

The identity of the palm kernel borer in West Africa is established, its correct name beingPachymerus cardo(Fåhr.); a neotype is designated forP. bactris(L.), the type species ofPachymerusThunberg; a new species,P. thoracicus, is described from Paraguay, and three new specific synonymies are made. A key in given to the species ofPachymerus, the definitive characters of all of which are described and illustrated.
Stem treatments to cotton with systemic insecticides against Heliothis zea (Boddie) and H. virescens (F.)
Authors: Ridgway R. L. , Bariola L. A. , Jones S. L. , Lowry W. L.
Published: July 2009

Laboratory and field-cage studies were conducted in Texas in 1965 to evaluate treatments of the systemic insecticides, Azodrin (3-hydroxy-N-methyl-cis-crotonamide dimethyl phosphate), Bidrin (3-hydroxy-N, N dimethyl-cis-crotonamide dimethyl phosphate), American Cyanamid CL-47031 (cyclic ethylene (diethoxy-phosphinyl) dithioimidocarbonate) and Temik (2-methyl-2-(methylthio) propion-aldehyde O-(methylcarbamoyl) oxime), applied incorporated in lanolin to the stems of cotton plants against Heliothis zea (Boddie) and H. virescens (F.). Reductions in numbers of developing larvae of H. zea were substantial on individual plants the stems of which had been treated with Azodrin or CL-47031 and which were artificially infested with eggs. When first-instar larvae of H. zea or H. virescens were caged on plants 3, 7 or 14 days after stem treatment with 2.5, 5.0 or 100 mg. Azodrin, Bidrin or CL-47031 per plant, net mortalities ranged from 21 to 80 per cent after three days. The mortality of adults of H. zea provided with sucrose solutions containing 1 p.p.m. of the systemic insecticides indicated that Azodrin and Bidrin were about equally toxic and much more so than CL-47031 and Temik, and that of adults caged on individual plants in flower that had been treated with Azodrin or CL-47031 suggested that the moths may be killed by the systemic action of these insecticides translocated to the nectar. When adults of H. virescens were released on plants each treated with Azodrin at 25 or 30 mg. in large field cages, reductions in the numbers of eggs deposited, attributed to the effect on the moths of the insecticide in the nectar, and in the numbers of developing larvae, were substantial. Azodrin was the most consistently effective of the four insecticides evaluated.
A leaf-mining scuttle fly (Diptera: Phoridae) as a pest of chickpeas (leguminosae) in Yugoslavia
Authors: Čakar Lj. , Disney R.H.L.
Published: July 2009

Megaselia arietina Disney sp. n. is described from Yugoslavia and Israel. Its larva leaf-mines chickpeas, Cicer arietinum. In Macedonia, recorded rates of infestation varied from 48.5–74.8% of the available leaves on a plant, with more than 60% of the leaves in a plot being typical. These levels of infestation seem to be related to the poor yields from the affected plots. The leaf-spot fungus Ascochyta rabiei (Coelomycetes) and the rust fungus Uromyces ciceri arietini (Uredinales) contribute to these reduced yields. The Uromyces spores are ingested by the female flies, but they are carried on the labella of the males without being ingested.
An improved Technique for Permanent Mounts of small Insects and Nematodes
Authors: Colless Donald H.
Published: July 2009

An improved technique is described for the preparation of permanent mounts of small Arthropoda and Nematoda, using a phenol-balsam mounting medium; a method is also described for clearing live, or freshly killed, specimens in strong chloral hydrate solution. The essential feature of the mounting method is the transfer of the specimen to a slide, in a drop of phenol, to which dry, powdered balsam is added and allowed to dissolve in situ. The mount is then dried and later covered in the usual fashion.
Notes on Some Rice Stem Borers (Lepidoptera: Pyralidae), with the Description of a new Species ofChiloZincken.
Authors: Martin Edward L.
Published: July 2009

Much confusion has arisen in the past with regard to the correct application of the names of certain Pyralid rice borers; I hope the following notes and illustrations will clarify the position.
The Preference shown by Myzus persicae (Sulz.) for Brassica Plants sprayed with Wetting Agents
Authors: Heathcote G. D. , Ward J.
Published: July 2009

Winged and wingless individuals of Myzus persicae (Sulz.), when offered a choice between unsprayed cauliflower seedlings and seedlings sprayed with a 0·1 per cent. aqueous solution of Lissapol N (a non-ionic wetting agent), preferred Lissapol-treated plants. This effect was statistically significant.

Further experiments showed that Aphids similarly preferred treated turnip seedlings to untreated seedlings. The preference for sprayed cauliflower seedlings was also shown when an anionic, a cationic and a mixed wetting agent were used.
Preliminary Note on the Biology of Glossina vanhoofi Henrard
Authors: Van Den Berghe L. , Lambrecht F. L.
Published: July 2009

Glossina vanhoofi Henrard has been found at the I.R.S.A.C. field station at Irangi in the Belgian Congo in dense rain-forest. The fly does not normally attack man and was collected only by looking for it in its resting places. The fly rests on small saplings, head down, at an average height of about 133 cm. A three-months' survey on a fly-round transecting three valleys and two hill-tops showed that the resting density (defined as the total number of resting flies observed per 10,000 metres of path) was correlated with the profile of the transect, the hill-tops yielding more flies than the valleys. The fly-round was worked three times a day and showed the highest density during early morning in all three months; in two of them there was little difference between midday and evening catches. The resting height varied in much the same way in all the sections of the fly-round and the average height remained virtually constant during the three months of the survey. There was a slight difference between the sexes as regards average resting height, the females perching somewhat lower than the males. The sex ratio of about 1:1 was very constant throughout the day and the period of the observations.

There is some evidence which seems to indicate that this species is strongly attracted to possible host-animals by a sense of smell.

Puparia have been found in “classical” sites, but the proportion containing living pupae was small. The duration of the pupal period is about 35 days under laboratory conditions at 26°C. and 90 per cent. relative humidity.

G. vanhoofi in captivity feeds readily on the porcupine, Atherurus africanus.
The Productivity of various Mosquito Breeding Places in the Swamps of Uganda
Authors: Goma L. K. H.
Published: July 2009

Six types of habitat in papyrus (Cyperus papyrus) swamps in Uganda were studied with regard to the production of mosquito larvae. A classification, of the types is given, which was largely based on the lapse of time since temporary clearing by cutting or burning had been carried out.

Altogether a total of 5,781 larvae belonging to 17 species was studied. Culex (Culex) guiarti Blanch., C. (C.) univittatus Theo. and C. (Neoculex) rubinotus Theo. were the dominant species, comprising together 78 per cent. of the total number of larvae. Anopheles gambiae Giles was not recorded. Samples of larvae were taken at intervals between mid-January and early April 1957. The sampling method used was unsuitable for those species of which the larvae obtain air from roots or stems of submerged vegetation, and these were excluded from the present study.

There was considerable variation in species and numbers of larvae and in their frequency in the different types of habitat.

It is concluded that (a) peripheral zones, especially in natural untouched swamps, are much more productive than the interior, (b) where swamps have been altered by cutting and by burning of papyrus and other vegetation, burnt habitats, whether recently or after the lapse of up to four or five months, have a very low productivity, (c) of the six chemical factors investigated (pH, K, Na, absorbed oxygen, free and saline ammonia and albuminoid ammonia) only the quantity of soluble organic matter, indicated by absorbed oxygen, and albuminoid ammonia, showed any relation to productivity, the least productive habitats containing the smallest quantity of organic matter.

Other possible factors in swamp water, which were not investigated, are mentioned. These are (a) the nature of soluble oxidisable organic matter, (b) conductivity, (c) ferruginous surface films and (d) iron in solution.
Studies on the Chemical Control of Wireworms (Agriotes spp.). II.—The direct and residual Effects of BHC, DDT, Aldrin and Chlordane
Authors: Raw F. , Potter C.
Published: July 2009

An experiment on Geescroft field, Rothamsted, from 1951 to 1954, tested the direct and residual effects of BHC, DDT, aldrin and chlordane applied to control wireworms (Agriotes spp.) in wheat.

The treatments applied were BHC seed dressing at 2 oz./bushel of a dressing containing 20 per cent. γ isomer of BHC; BHC 3·5 per cent. dust, combine-drilled to give 3·8–4·0 oz. γ isomer per acre; DDT 5 per cent. dust, combine-drilled to give 7·5 lb./acre technical DDT; aldrin 1·78 per cent. dust, combine-drilled to give 3·56 lb./acre technical aldrin, and chlordane 5 per cent. dust, combine-drilled to give 5 lb./acre chlordane.

In the year of application, the first out of old grass, when wireworm attack was slight, the plots treated with BHC, aldrin and chlordane, combine-drilled, gave significantly greater yields than the control plots. In the following year, when wireworm attack was heavier, residual effects on yield were observed on plots initially treated with BHC, DDT, aldrin and chlordane, combine-drilled. In the third year, residual effects on yield were observed on the plots initially treated with BHC, aldrin and chlordane, combine-drilled.

No direct or residual effect of BHC seed dressing was observed.

The residual effects are closely associated with the effect of the treatments on the wireworm population.

The results are compared with those of previous experiments and the increases in yield from the various treatments are discussed briefly.
Studies of British Anthomyiid Flies. VIII.—The Carnation Fly, Hylemyia brunnescens (Zett.)
Authors: Miles Mary
Published: July 2009

The Carnation Fly, Hylemyia brunnescens (Zett.), which attacks cultivated species of Dianthus, has been studied in detail because the account given by Bruneteau (1930) was incomplete and that given by Séguy (1932) of two flies (H. brunnescens and H. cardui (Mg.)) on carnations was also incomplete and the identities of the stages studied were not fully established. For the first time, the development of H. brunnescens from egg to adult has been completed under observation and bred adults have been maintained in captivity until eggs were laid. The eggs, larvae and adults are described.

Eggs were laid in autumn. Oviposition began in the field on 7th September 1954 and on 12th September 1955 and eggs were present until early November. The behaviour of flies in captivity confirmed that eggs were laid only in autumn.

The larvae mined in the leaves and shoots. Early larvae finished feeding in November and entered the soil. Late larvae remained on the plants and fed intermittently through January and February, whenever the temperature was suitable. Mature and immature larvae on the plants survived exposure to severe frosts. Hibernation took place in the larval stage in the soil or in the feeding sites. Pupation occurred from mid-March to mid-April and the pupal stage lasted about eight weeks.

The emergence period for 122 flies was 4th–20th June 1955 with a peak period from 6th–12th June; other observed emergence periods were 30th May–4th June (1950), 2nd–9th June (1953) and 16th–26th May (1954). Captive flies lived from two to four months. They were active during the summer but they did not reach sexual maturity and begin to lay eggs until late August. There is thus only one generation a year and the slow development to sexual maturity ensures that the larval period occurs in autumn when the foliage of the host-plants is freshest and most abundant.
An unconventional use of piperonyl butoxide for managing the cotton whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)
Authors: Devine G.J. , Denholm I.
Published: July 2009

Bemisia tabaci (Gennadius) is a pest of global importance which resists many conventional insecticides. Novel strategies for control are required and these may incorporate compounds whose lethal and sublethal effects have gone unremarked. Although most commonly employed as an insecticide synergist, piperonyl butoxide alone was lethal to predominantly second instar nymphs of the cotton whitefly, B. tabaci at LC50s of between 60 and 600 ppm, depending on the strain. Formulated and technical material were similarly toxic and far more so than detergents. Some strains exhibited slight tolerance (c. 3–10 fold) but there was no correlation of this with the presence of known resistance mechanisms or enzyme banding patterns. Residues of piperonyl butoxide alone were toxic to adult B. tabaci at c. 2000 ppm which was similar to the toxicity of paraffin oil. Piperonyl butoxide also increased developmental times among B. tabaci nymphs at doses as low as 10 ppm and exerted a transient effect on oviposition. There was strong evidence that it did not reduce the feeding activity of insects surviving treatment. Such effects offer scope for incorporating this compound into resistance management programmes, especially in conjunction with natural enemies (e.g, parasitoids active specifically against immature hosts).
Impact and oviposition behaviour ofAgeniaspis fuscicollis(Hymenoptera: Encyrtidae), a polyembryonic parasitoid of the apple ermine moth,Yponomeuta malinellus(Lepidoptera: Yponomeutidae)
Authors: Kuhlmann U. , Babendreier D. , Hoffmeister T.S. , Mills N.J.
Published: July 2009

The distribution and extent of parasitism of the apple ermine mothYponomeuta malinellusZeller by the polyembyronic encyrtid parasitoidAgeniaspis fuscicollis(Dalman) were examined in a three year field study and related to oviposition behaviour in the laboratory.Ageniaspis fuscicollisattacks egg batches of its host and kills the final instar larvae, which feed gregariously from within tents. Host population densities in the field were low, from 1.5 to 2.2 tents per 100 leaf clusters, and parasitism increased from 7.8% to 18% over the three year period. Parasitism was independent of host density at the whole tree scale, but at the individual tent scale, the probability of a tent containing parasitized host larvae increased and percent parasitism decreased with the number of host larvae per tent. Observations on the oviposition behaviour ofA. fuscicollisin the laboratory revealed that parasitoids distributed their eggs randomly within host egg batches. On average, they spent almost two hours on an egg batch and laid 44% of their egg load of 132 eggs into the first egg batch visited, leading to a mean of 1.4 eggs laid per host egg through frequent self-superparasitism of hosts. The percentage of eggs receiving one or more ovipositions was independent of the size of an egg batch, contradicting our field observations of inverse density dependence. Factors that might account for the differences in rates of parasitism and attack distributions between laboratory and field data are discussed.
Three new Strains of Amphorophora rubi (Kalt.) on cultivated Raspberries in England
Authors: Briggs J. B.
Published: July 2009

Previous work on strains of Amphorophora rubi (Kalt.) is discussed and evidence is presented to show that the form on European raspberry can be divided into three strains. These are designated European raspberry strain 1, 2 and 3. The distribution, abundance and importance of the strains in relation to plant breeding for resistance to A. rubi is discussed.
A Comparative Study of the Soil Conditions favoured by certain Melolonthid and Tenebrioned Pests of Tobacco in Southern Rhodesia
Authors: Bünzli G. H. , Büttiker W. W.
Published: July 2009

An investigation was made to determine the factors governing the distribution pattern of the larvae of certain species of Melolonthids and Tenebrionids; these are known to be serious pests of tobacco plants in Southern Rhodesia.

Observations were made on mixed populations of the white grubs, larvae of Anomala exitialis Pér. and Schizonycha profuga Pér. (MELOLONTHINAE), on the one hand, and on those of the false wireworms, larvae of Psammodes similis Pér. and P. scrobicollis (Fhs.) (TENEBRIONIDAE), on the other.

It was found that the habitats favoured by white grubs had a higher clay, silt and organic matter content than those favoured by false wireworms. This was indicated by the darker brown colour of the soil; the clay ratio of the soils of the two types of habitat was as 1 to 0·725 and the nitrogen ratio as 1 to 0·524, respectively.

Heavy infestations of tobacco fields are associated with 60,000 white grubs or 1,500 false wireworms per acre. The white grubs complete their life-cycle in one year, the larvae obtaining the food requirements necessary for their develop ment in the 4 to 5 months of the wet season. The false wireworms have a two-year life-cycle, the active feeding stages of the larvae being spread over 18 to 21 months, comprising both wet and dry seasons.

The infestations by the two classes of insect do not overlap in space to any great extent but are governed by the nature of the soil, the white grubs favouring areas in which the soil has a higher nutrient value and the false wireworms areas where the soil is poorer.

Reference is made to parasitisation of white-grub larvae in two areas, where the soil had an abnormally high nitrogen content, by a species of Tiphia in the one area and by entomogenous fungi in the other.

False wireworms have not been found to be similarly attacked under field conditions.
The Oviposition and Duration of Life of a small Strain of the Rice Weevil,Calandra oryzae(L.), in Sierra Leone
Authors: Prevett P. F.
Published: July 2009

A study has been made of the rate of oviposition, on parboiled milled rice, of the small strain of the rice weevil,Calandra oryzae(L.), under normal laboratory conditions of temperature and relative humidity (means 27°C., 80% R.H.) in Sierra Leone, and of the utilisation of grains for oviposition.

On the average, a female laid 68 eggs in all, over an oviposition period of 71 days, the peak of egg-laying being reached during the third week. Only 13 per cent, of grains were utilised. Differences between the results obtained and those recorded by previous workers are discussed.

The mean length of life of male and female weevils was found to be 113 and 97 days, respectively.
Acclimatization affecting the Position of the Cold and Heat Death Points of Larvae ofAëdes aegypti(L.)
Authors: Mellanby Kenneth
Published: July 2009

In experiments withAëdes aegypti(L.), fourth-stage larvae bred at 30°C. survived exposure to 0·5°C. for 7 hours, but none recovered after exposure for 17 hours, although nearly all those from the same culture that had been acclimatized for one hour to 18 or 20°C. did so. No such effect followed acclimatization at 10°C., at which larvae are in chill coma. Larvae acclimatized at 18°C. survived exposure to 5°C. for longer than did those from 30°C. Earlier work showed that the thermal death point, for a one-hour exposure, was 42°C. for larvae acclimatized at 30°C. but rose to 44°C. for larvae acclimatized to 37°C. It is concluded that the effects of high or low extremes of temperature may be substantially modified by a brief period of acclimatization at a less extreme temperature.
The flight of Culicoides impunctatus Goetghebuer (Diptera, ceratopogonidae) over moorland and its bearing on midge control.
Authors: Kettle D.S.
Published: July 2009

In the summer of 1958, experiments were conducted in the vicinity of Brunston Muir, Midlothian, 11 miles SE. of Edinburgh, to measure the flight range of Culicoides impunctatus Goetgh. from its breeding site in the direction of the prevailing south-westerly wind. Thirty-six sticky traps were exposed for six weeks from 27th May to 7th July and captured 23,211 specimens of Culicoides, of which 20,105 were of C. impunctatus (7,207 males and 12,898 females).

Eleven of the traps were arranged in a line over 1,200 yd. The catch of females did not alter for 400 yd., then decreased to a new level which remained constant from 600 to 1,200 yd. This decrease was associated more with the absence of livestock after 550 yd. than with any density/distance regression. The male distribution was similar to that of the females.

Ten more traps stretched over 750 yd. and again no regression was discernible. The female distribution was affected more by the availability of hosts than distance from the breeding site. The male distribution here was different. They appeared to pass less readily through a gap in a narrow belt of woodland than did the females.
Trapping as a means of studying the game tsetse, Glossina pallidipes Aust.
Authors: Morris K. R. S.
Published: July 2009

In an area of sleeping sickness due to Trypanosoma rhodesiense in Uganda, Morris's ‘ animal ’ traps were used to study the activity and the relations with habitat and hosts of the vector, Glossina pallidipes Aust., a tsetse difficult to sample by conventional fly-round methods.

This type of trap was found to give samples both numerically greater and more truly representative of the tsetse population present than did either fly-boys or Chorley's bicycle screen.

Black traps showed an over-all superiority to brown traps, greatest during the rains and disappearing in the dry season, and this was related to the tsetse being attracted by the trap as representing a natural host.
Laboratory observations on the life-history and ethology of Mansonia mosquitos
Authors: Gillett J. D.
Published: July 2009

The rearing of a complete generation of Mansonia (Coquillettidia) aurites (Theo.) is described with notes on the methods used.

Variation in the leg ornamentation of the adults forming the progeny of a single egg-raft was found to cover the range usually observed in this species.

A plea is made for conformity in the use of terms describing the various kinds of aggregations of eggs.

Egg-rafts are discussed, and a tentative key is given to the eggs of six of the Ethiopian species of Coquillettidia, based on egg-raft shape.

A modification of the ‘natural’ arrangement is suggested for the Ethiopian species of Coquillettidia, based not only on adult and larval characters, but on oviposition behaviour as judged by egg-raft shape.

The possibility of natural interspecific hybridisation is mentioned.

The general slowness in many of the life processes found in the genus is put forward as an adaptation to its peculiar mode of life.