bluuebunny/crossref_metadata_2025_split huggingface dataset:
The biology of Anopheles claviger (Mg.) (Dipt., Culicidae) in southern England
Authors: Service M. W. 
Published: July 2009

AbstractThe biology of Anopheles claviger (Mg.) was studied for a varying number of years in three localities in southern England. The fluctuations in the proportions of the larval instars and pupae were studied by weekly sampling throughout the year. The population overwintered from October to April as pre-adults, and in mid-winter larval development was arrested, but was resumed in March. The construction of a simple life-table showed the existence of a large mortality of immature stages during the overwintering period. Females were sampled at two localities by human bait catches, and at one also by insect suction traps. There was an interval of 1–2 weeks between adult emergences in April and blood-feeding, during which time females apparently fed on sugar solutions. Maximum biting densities of nullipars in May and September showed that A. claviger was bivoltine. The physiological age structure of the population showed that most parous adults at bait had oviposited only once or twice, but a few females had laid four batches. Live Hygrobatid-type mites proved reliable in indicating nulliparity. Mature larvae developed in the eggs 5–7 days after oviposition and while most eggs hatched within the next three days, a few remained unhatched until the 30th day. Females of the second generation (September) laid fewer eggs than those of the first generation (May). About six days were required for blood digestion, and females supplied with sugar were able to live 46 days. The marked delays between successive gonotrophic cycles in natural populations would make parous rates unreliable for the estimation of daily mortalities.
Reproductive, developmental and nutritional biology of the tomato moth,Lacanobia oleracea(Lepidoptera: Noctuidae) reared on artificial diet
Authors: Corbitt T. S. , Bryning G. , Olieff S. , Edwards J. P. 
Published: July 2009

AbstractSeveral aspects of the biology of the tomato moth,Lacanobia oleracea(Linnaeus) were investigated when these insects were fed an artificial diet and kept under laboratory conditions. The six larval stadia occupied a total period of 35.6 days at 20°C and 65% r.h. Larvae of each stadium could be separated by their head capsule widths, but not weight ranges, which overlapped. Feeding studies carried out on larvalL. oleracearevealed instar dependent changes in the indices of food consumption and utilization. Larvae increased in weight from the fourth to sixth instar due to a combination of the increased efficiency with which ingested food was converted to body tissue, and increased food consumption by older larvae. Sixth (final) instar larvae exhibited three distinct behavioural phases; during one of these, the feeding phase, larvae consumed a greater amount of diet than either the fourth or fifth instars. The mean pupal period of non-diapausing pupae was 25 days. Pupal diapause was induced when larvae were reared under short day conditions. The male to female sex ratio of adult moths was 1:1.3. Mating generally began during the first scotophase after adult eclosion, and stopped soon after the start of the next photophase. Females usually mated only once, but males were capable of mating at least seven times. Oviposition normally commenced on day 2 of adult life, and the mean total egg production was 1186 eggs/female. Sex pheromone components were not present in solvent extracts of the pheromone glands of 20-day-old female pupae, but low levels were detected in pharate adults. A further increase in pheromone levels in newly-emerged moths was detected and, in isolated virgin moths, pheromone levels increased each day of adult life until day 9. Pheromone levels were significantly lower in two-day-old mated adult females, than in two-day-old virgins.
Effect of temperature on survival and rate of virogenesis of African horse sickness virus in Culicoides variipennis sonorensis (Diptera: Ceratopogonidae) and its significance in relation to the epidemiology of the disease
Authors: Wellby Martin P. , Baylis Matthew , Rawlings Peter , Mellor Philip S. 
Published: July 2009

AbstractCulicoides variipennis sonorensis Wirth & Jones and C. nubeculosus (Meigen) were orally infected with African horse sickness virus (AHSV) type 9 and subsequently incubated at 10, 15, 20 and 25°C (R.H. 80%±10%). A time course of infection rates and virus titres was recorded by assaying flies individually or in pools, and survival rates of flies were also estimated. Survival rates at 10, 15 and 20°C were very similar and 80–90% of flies remained alive after 14 days; at 25°C after the same period survival was reduced to 40%. None of the C. nubeculosus became persistently infected with AHSV, but the virus took longer to clear as the incubation temperature dropped. At temperatures of 10, 15, 20 and 25°C virus was undetectable on days 12, 8, 5, and 4 days post infection (dpi), respectively. In C. v. sonorensis both the infection rate and rate of virogenesis were related to temperature. At 25°C a maximum mean titre of 104.3 TCID50/fly was reached by 9 dpi and the infection rate remained between 60 and 80%. At 20°C virogenesis was slower and a maximum mean titre of 104.3 TCID50/fly was reached only after 23 days; the infection rate was also reduced to 50–70%. At 15°C there was an overall decline in virus titre with time, although between 12 and 15 dpi some pools of flies contained 103.0–104.0 TCID50/fly, demonstrating that virogenesis can occur. The infection rate at this temperature decreased dramatically to 0–15% after 9 dpi. At 10°C there was no detectable virogenesis and all pools tested at 13 dpi were negative. The apparent infection rate dropped to 0–5% between 13 and 35 days post infection. However, when surviving flies were then returned to 25 °C for 3 days the infection rate increased to 15.5%. It therefore appears that at low temperatures the virus does not replicate but infectious virus may persist at a level below that detectable by the usual assay systems. The implications of these findings for the epidemiology of AHS are discussed.
The sugarcane lophopid planthopperPyrilla perpusilla(Homoptera: Lophopidae): a review of its biology, pest status and control
Authors: Kumarasinghe N.C. , Wratten S.D. 
Published: July 2009

AbstractThe biology, damage and control of the sugarcane pestPyrilla perpusillaWalker are reviewed. The present systematic position, distribution and the range of alternative host plants are surveyed and the life cycle and the extent of damage caused by the pest are considered in detail. The factors influencing the abundance of the insect are discussed, with emphasis on their use in reducing the population of the pest. Much of the published data in this area is based on un replicated observations. However, potential biological control agents for the insect are evaluated with special reference to the most effective nymphal and adult ‘parasitoid’, the mothEpiricania melanoleuca(Fletcher). Many other potential biological control agents have received some study, but in most cases, little more than basic biological information on phenology and life cycle has been published. As considerable changes in chemical control practices over the past fifty years have occurred, these, together with other control methods such as agronomic, mechanical, cultural and host plant resistance approaches are discussed along with prospects for the future, sustainable control of the pest. Research areas which are in need of more work are identified: these are biological control and cultural practices. It is suggested that an integrated approach to future research should be made, incorporating at least host-plant resistance and predation.
Control of yellow stem borer,Scirpophaga incertulas(Lepidoptera: Pyralidae) by mating disruption on rice in India: effect of unnatural pheromone blends and application time on efficacy
Authors: Cork A. , De Souza K. , Krishnaiah K. , Kumar D.V.S.S.R. , Reddy A. Ashok , Casagrande E. 
Published: July 2009

AbstractSingle applications of slow-release pheromone formulations were used to control yellow stem borer,Scirpophaga incertulasWalker, by mating disruption in two trials on rice in India. The first trial compared the efficacy of two formulations containing 1:10:1 and 1:10:0 ratios of (Z)-9-hexadecenal, (Z)-ll-hexadecenal and (Z)-9-octadecenal, components of theS. incertulaspheromone, and a commercially-available formulation, Selibate CS, containing the relatedChilo suppressalisWalker pheromone, a 1:10:1 blend of (Z)-9-hexadecenal, (Z)-ll-hexadecenal and (Z)-13-octadecenal, with farmers' practice plots treated with insecticides. Pheromone trap catches indicated that in each of the pheromone-treated plots the catches of male moths were reduced by up to 98% compared with catches in the insecticide-treated plots suggesting that pheromone-mediated communication was disrupted. Larval damage ranged from 5.7 to 8.1% white heads (WH) in the insecticide-treated plots compared to a significantly reduced range of 2.1 to 2.4% WH in the pheromone-treated plots. There was no significant difference between the damage estimates recorded for each of the different pheromone treatments. A second trial compared the effect on efficacy of applying the two-component pheromone formulation on different dates, 9–12 and 39–44 days after transplanting. Both pheromone treatments gave significantly lower levels of WH damage compared to equivalent insecticide treated plots; 1.8, 2.0, and 6% respectively. In both trials rice grain yields increased by between 5 and 12% in pheromone-treated plots compared to insecticide treated plots, which was due, at least in part, to the cumulative effect of reduced stem borer damage in both the tillering and reproductive stages of the crop cycle. The formulations exhibited pseudo-zero order release rates with field lives of between 70 and 90 days.
Comparative status of insecticide resistance in theHelicoverpaandHeliothisspecies (Lepidoptera: Noctuidae) of south India
Authors: Jadhav Deepak R. , Armes Nigel J. 
Published: July 2009

AbstractHelicoverpa armigera(Hübner),H. assultaGuenée andHeliothis peltigera(Denis & Schiffermüller) were collected as mixed populations from safflower and the wild hostDatura metel, from Patancheru, Andhra Pradesh, India, in 1992 and 1993, and their toxicological responses to insecticides determined. BothHelicoverpa armigerastrains were highly resistant to cypermethrin, fenvalerate, endosulfan and quinalphos insecticides, based on resistance ratios relative to laboratory reared susceptible strains. There was no evidence of resistance development inH. assultaandHeliothis peltigerato the same chemicals. Light trap data collected from 1974 to 1987 showed thatHelicoverpa armigerawas at least 100 × more abundant than the other two species over most of the cropping season. Peak catches ofH. assultaandHeliothis peltigerawere confined to defined times in the season, corresponding with the flowering and fruiting periods of their respective host plants; August-October forHelicoverpa assultaand November-December forHeliothis peltigera. Helicoverpa armigeraon the other hand, because of its high polyphagy on commercial and wild hosts, was abundant between August and April. Resistance has not developed inH. assultaandHeliothis peltigerain southern India, probably because of their restricted host range, limiting exposure to insecticides.
The design of target barriers for tsetse flies, Glossina spp. (Diptera: Glossinidae)
Authors: Muzari M.O. , Hargrove J.W. 
Published: July 2009

AbstractTwo small-scale experiments were carried out to test the effectiveness of narrow target barriers against re-invasion by Glossina pallidipes Austen and G. m. morsitans Westwood. The barriers consisted of either one or two lines of targets, with the targets placed at distances of c. 16 m apart within the lines. At this spacing the targets are so close together that a fly could scarcely fail to see at least one target as it crossed the barrier. Nonetheless, in both cases, flies penetrated the barriers with probability c. 10% as judged by catches in odour-baited traps on either side of the barrier. Narrow barriers, even at very high target density, are ineffective against tsetse invasion. This accords with previous theoretical predictions and mark-recapture studies, and suggests that wider barriers are needed for the prevention of re-invasion of cleared areas by tsetse.
Summer diapause in Chrysolina hyperici and C. quadrigemina (Coleoptera: Chrysomelidae) in relation to biological control of St John's wort, Hypericum perforatum (Clusiaceae)
Authors: Schöps K. , Syrett P. , Emberson R.M. 
Published: July 2009

AbstractThe success of the chrysomelid beetles, Chrysolina hyperici (Forster) and C. quadrigemina (Suffrian), used widely for biological control of St John's wort (Hypericum perforatum) seems to depend on the synchronization of their phenologies with climate. The factors governing the termination of diapause in the field and laboratory were assessed in New Zealand. Before summer diapause, C. hyperici made up more than 70% of adult beetles in the field. Both species entered summer diapause at the beginning of January, but C. quadrigemina terminated diapause 3–4 weeks earlier (early March) than C. hyperici. Both male and female C. quadrigemina and male C. hyperici adults became sexually mature during summer diapause but C. hyperici females still had immature ovaries. Females of C. quadrigemina began laying eggs immediately after summer diapause but females of C. hyperici did not oviposit until more than 2 weeks after they terminated diapause in late March. In the laboratory summer diapause was terminated in both species by short day length, not by simulated rainfall, contradicting previous assumptions that autumn rainfall is the critical factor. The demonstrated differences in phenology are reflected in different overwintering strategies for the two species. Because C. hyperici overwinters in the egg stage, this species will be a more successful biological control agent of St John's wort in countries with cold winters than C. quadrigemina, which overwinters in the more vulnerable larval stage. However, in countries with mild winters C. quadrigemina is more successful in controlling St John's wort than C. hyperici, since it has a developmental lead with its larvae feeding and growing during the winter.
Effects of intercropping on maize stemborers and their natural enemies
Authors: Skovgård Henrik , Päts Peeter 
Published: July 2009

AbstractThe effects of maize–cowpea intercropping on three lepidopteran stemborers (Chilo partellus(Swinhoe)C. orichalcociliellus(Strand) andSesamia calamistisHampson) and their natural enemies were studied in Kenya. Oviposition was not affected by intercropping, but significantly fewer larvae and pupae were found in the intercrop. Egg parasitism was significantly higher in the intercrop reaching as high as 80% and was positively density dependent. Larval and pupal parasitism remained between 3 and 20%, but neither of these were affected by intercropping or host density. The main predators, ants and wandering spiders, were not augmented by intercropping, but an inverse relationship in abundance was found between these two predator groups. It is concluded that maize intercropped with cowpea has only limited potential as a method of controlling the key pests in maize.
The Host-animals of Glossina morsitans at Daga-Iloi
Authors: Weitz B. , Jackson C. H. N. 
Published: July 2009

Blood smears from 378 examples of Glossina morsitans Westw. from the Daga-Iloi fly-round were tested by serological methods, including a new test involving the inhibition of agglutination of tanned red blood cells.About half the feeds were derived from wart-hog or bushpig, though these apparently formed only some ten per cent, of the ungulate mammals present.
The Arthropod Population of the Soil under Elephant Grass in Uganda
Authors: Salt George 
Published: July 2009

Six soil samples from elephant-grass leys at Kawanda, Uganda, gave collections representing a population of 87,147 arthropods per sq. metre in the top 12 in. of soil.Six samples from adjacent cultivated ground gave collections representing a population of 26,150 arthropods per sq. metre.These numbers are compared with the population of arthropods found in the soil of grazed pastures in East Africa.The greater population under elephant grass is attributed to the presence of a crumb structure and to the protection afforded by elephant grass against insolation.It is suggested that the nitrogen contained in these soil arthropods, especially that locked up in the chitin and sclerotin of their skeletons, is part of the nitrate that becomes available some weeks or months after elephant-grass leys are cultivated.
Studies on Aqueous Suspensions of Insecticides. Part V. The Sorption of Insecticides by Soils
Authors: Barlow F. , Hadaway A. B. 
Published: July 2009

It is suggested that if the vapour of an insecticide is rapidly adsorbed by a substrate the rate of volatilisation of the molecules of insecticide particles lying on the substrate is greatly increased. This explains the rapid loss of effectiveness of wettable powders on some soils. After the insecticide has been sorbed it is concentrated at and near the treated surface but afterwards slowly diffuses inwards. This diffusion reduces recoveries of insecticides from surface scrapings.DDT can be recovered quantitatively from Uganda mud blocks 12 months after sorption is complete. Therefore, on this mud at least, catalytic decomposition does not occur.A test has been devised for measuring the sorptive capacities of soil samples for non-polar vapours. It indicates if a soil is highly active but those with lower or negligible activities do not give a good correlation.A survey of 18 soils from different parts of the world suggests that rapid inactivation of an insecticide by sorption should be expected on any red lateritic soil. Generally, others are inert or show only low activity.Attempts to reduce or abolish the sorptive powers of Uganda soil have not been successful and the only effective method known at present is to limewash the walls before spraying. Pretreatment with a size solution also stops sorption but, unlike limewashing, at the same time reduces the efficiency of a subsequently applied wettable powder.Finally, work by various authors on the inactivation of insecticides on mud surfaces is reviewed.
The Effect of Photoperiod and Temperature on Reproduction in Acyrthosiphon pisum (Harris) and on the Forms produced
Authors: Kenten Joyce 
Published: July 2009

The effect of photoperiod and temperature on the production of the various forms of Acyrthosiphon pisum (Harris) has been studied. In this study apterous virginoparous females were exposed throughout their lifetime to two photoperiods (8 hr./24 hr. and 16 hr./24 hr.) and six different temperatures. At each of the temperatures the apterae (parent Aphids) received one of four treatments of photoperiod, i.e., (1) 8 hr./24 hr. photoperiod throughout their whole life; (2) 8 hr. /24 hr. photoperiod during the period from birth until the last (imaginal) moult (nymphal period), followed by 16 hr./24 hr. photoperiod from the last (imaginal) moult until death (the adult period); (3) 16 hr./24 hr. throughout life; (4) 16 hr./24 hr. during the nymphal period followed by 8 hr./24 hr. during the adult period. The offspring produced by the various parents were collected at successive intervals, and their form determined.Four main forms of offspring were produced: apterous and alate virginoparae, males and oviparae. In addition, a subsidiary form of the apterous virginoparae was obtained, which had sensoria on the hind tibiae.
Host distribution, larviposition behaviour and generation time ofSarcophaga penicillata(Diptera: Sarcophagidae), a parasitoid of conical snails
Authors: Coupland James B. , Baker G. 
Published: July 2009

AbstractHost characteristics, hyperparasitism, larviposition behaviour and generation time ofSarcophaga penicillataVilleneuve a parasitoid of the conical snail,Cochlicella acutaMüller (Mollusca: Helicidae) in southern France are described. Only snails which aestivated on vegetation were found to be parasitized byS. penicillata. Sarcophaga penicillatapreferredC. acutawhich were both significantly higher off the ground and larger in size than the population averages. Of the 2768 snails collected at the study site, 4% (112) were parasitized byS. penicillata, of which 36.6% (41) failed to emerge while 34% (38) were hyperparasitized. The predominant hyperparasite wasNovitzkyanus cryplogasterBouček (Hymenoptera: Pteromalidae) which was responsible for 79% (30) of the hyperparasitism. LarvipositingS. penicillatawere observed to fabricate a hole in the epiphragm of resting snails in which they deposited one larva. After larviposition, femaleS. penicillataremained with the freshly parasitized snail a mean time ± SE of 25.2 ± 10.3 min. It is suggested that this may be an adaptive response to avoid superparasitism. The mean generation time ofS. penicillatawhen reared in the laboratory was 18 days, indicating that more than six generations are possible during summer in the south of France. During winter,S. penicillataenters diapause in the pupal stage within a host snail for up to 6 months. The possible utility ofS. penicillataas a biological control agent of introduced conical snails is discussed.
Spodophagus, a new genus of Pteromalidae (Hymenoptera), for an important parasite of Spodoptera littoralis (Lepidoptera: Noctuidae) in Madagascar
Authors: Delvare Gérard , Rasplus Jean-Yves 
Published: July 2009

AbstractSpodophagus, gen. n. (Pteromalidae: Pteromalinae), is described to include the single species S. lepidopteraecomb. n., which was originally described from Madagascar by Risbec (1952) in the genus Oxyglypta. A lectotype is selected for O. lepidopterae, and the species is redescribed and illustrated. This pteromalid is a parasitoid of Spodoptera littoralis, an important pest, which is resistant to several classes of insecticides in Madagascar. Spodophagus lepidopterae is thus a potential agent for the biological control of Spodoptera spp. in Africa and elsewhere.
Analysis of the reproductive potential of diploid males in the waspDiadromus pulchellus(Hymenoptera: Ichneumonidae)
Authors: El Agoze M. , Drezen J. M. , Renault S. , Periquet G. 
Published: July 2009

AbstractIn the ichneumonid waspDiadromus pulchellus(Wesmael), diploid males may regularly be produced in laboratory populations by inbreeding. They are viable, produce diploid sperm and are equally capable of multiple inseminations as are haploid males. Their spermatozoa are also able to penetrate the oocyte. Progeny sired by diploid males are essentially haploid sons with only a few daughters. The sons are normal haploid individuals, produced in a frequency significantly higher than in crosses between females and haploid males. The daughters are normal diploid females probably resulting from the fertilization of an oocyte by an exceptional haploid sperm rarely produced by diploid males. Triploid individuals were not observed and their absence was correlated with the high mortality observed during the first developmental stages. The death of these individuals is discussed in the light of the phenomenon of superparasitism to explain the increase in the frequency of sons produced in crosses with diploid males. Despite their viability, their ability to produce sperm and their normal potential insemination, diploid males ofDiadromus pulchellusare therefore almost sterile.