bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organophosphorus insecticide resistance in a new strain ofCulex quinquefasciatus(Diptera: Culicidae) from Tanga, Tanzania
Authors: Khayrandish A. , Wood R.J. 
Published: July 2009

AbstractFourth instar larvae of a new strain ofCulex quinquefasciatusSay from Tanzania (TANGA) were tested for insecticide resistance. Initially, the resistance ratio (RR) to chlorpyrifos was 41.8, to temephos 30.8, to propoxur 3.7. After 2–3 years of laboratory culture, resistance to chlorpyrifos and propoxur had declined (chlorpyrifos 5.7, 3.8; propoxur 1.9, permethrin 1.9). Significant synergism was found between s, s, s-tributyl trithiophosphate (DEF) and chlorphyrifos, reducing the RR from 8.0 to 2.5. Synergism between piperonyl butoxide and permethrin was less than in a susceptible control strain. Twelve esterase isozymes of different relative mobilities (Rm) on polyacrylamide gel electrophoresis were identified, ten of which remained when the strain was reinvestigated two years (approximately 32 generations) later. Null activity for all but one of these bands was observed in some larvae. Four esterase bands (Rm 0.25, 0.27, 0.31, 0.34, designated A2, A3, B2, B3) showed polymorphism in activity, with very intense bands in some larvae. The mean frequency of bands with activity greater than standard, declined as organophosphorus (OP) resistance declined, but resistance was unconnected with the frequency of nulls at these positions. In mass larval assays ofin vitrosensitivity of acetylcholinesterase (AChE) to propoxur, the I50exceeded 10x10−4M, compared with 0.1x10−4M in a reverted resistant strain (RANGOON). Single larvel assays revealed heterogeneity, which was interpreted on the basis of an AChE resistance allele (AceR) with a frequency of 0.23.
A review of the species resemblingChilocorus nigrita(Coleoptera: Coccinellidae): potential agents for biological control
Authors: Booth R.G. 
Published: July 2009

AbstractChilocorus nigrita(Fabricius) is a well-known predator of scale insects. It has been widely used for biological control and has spread naturally beyond its previous native range over the last three decades or so. Three other Oriental species closely resemblingC. nigritacan now be separated.Chilocorus melasWeise is redescribed and a lectotype designated. Chilocorus gressitti Miyatake is a junior synonym ofC. melas.Chilocorus subindicusfrom the southern parts of the Indian subcontinent andC. graciliorfrom eastern Indonesia are described as new.
The bionomics ofListronotus bonariensis(Coleoptera: Curculionidae) in Canterbury, New Zealand
Authors: Goidson S.L. , Proffitt J.R. , Baird D.B. 
Published: July 2009

AbstractA study was conducted in 1990–1995 in Canterbury, New Zealand to describe the phenology and seasonal abundance of all stages of the Argentine stem weevilListronotus bonariensis(Kuschel), a New Zealand pest of Gramineae. Of note were major fluctuations in the densities of all stages from one season to the next which were not explained directly in terms of the availability ofNeotyphodium lolii-free ryegrass tillers. The overwintering mortality rates ofL. bonariensiswere found to be linear and remarkably similar between seasons and locations in the absence of pathogens. This study also showed that care must be taken in the use of existing data to analyse the impact of the recently introduced South American parasitoid waspMicroctonus hyperodaeLoan as a biological control agent ofL. bonariensis; errors may exist because of earlier sampling biases. In spite of the confounding effects of seasonal variation in theL. bonariensispopulation, reduction in the size of theL. bonariensisfirst summer generation egg and larval peaks coincided with a build up ofM. hyperodae.
Comparative toxicity of foliar and systemic applications of acetamiprid and imidacloprid against the cotton whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)
Authors: Horowitz A.R. , Mendelson Z. , Weintraub P.G. , Ishaaya I. 
Published: July 2009

AbstractComparative bioassays of two chloronicotinyl insecticides, acetamiprid and imidacloprid, against the whitefly Bemisia tabaci (Gennadius), using foliar and systemic applications, were conducted under laboratory conditions and in field trials. Under controlled conditions, the ovicidal activity of foliar applications of acetamiprid on cotton seedlings was much higher than that of imidacloprid. According to LC50 and LC90 values, acetamiprid was 10- and 18-fold more potent than imidacloprid. Both compounds were effective when applied to soil against whitefly adults; however, the potency of imidacloprid was somewhat higher than that of acetamiprid 2, 7 and 14 days after application; resulting (with the concentration of 25 ml a.i./l) in adult mortality of 90, 93, and 96% and 76, 84, and 76% respectively. In an experimental cotton field, the efficacy of foliar applications of 60 g a.i./ha acetamiprid and 210 g a.i./ha imidacloprid was compared. Field residual activity of acetamiprid to whitefly adults lasted for approximately ten days, compared with three days for imidacloprid.
Survival and mortality of grasshopper egg pods in semi-arid cereal cropping areas of northern Benin
Authors: Shah P.A. , Godonou I. , Gbongboui C. , Hossou A. , Lomer C.J. 
Published: July 2009

AbstractSurveys of egg pods of agriculturally important grasshoppers were carried out in northern Benin between 1992 and 1995. Searches were made of oviposition sites under shrubs of the perennial legumePiliostigma thonningialong field margins. In 1993 and 1995, surveys were extended to include sorghum,Sorghum bicolor, and the perennial thatch grassVetiveria nigritana. The four principal grasshopper species found at these oviposition sites wereHieroglyphus daganensisKrauss,Cataloipus fuscocoeruleipesSjöstedt,Kraussaria angulifera(Krauss) andTylotropidius gracilipesBrancsik comprising 86% of 4545 identified egg pods while 651 egg pods could not be identified to species level. Predation by meloid beetles (Epicauta, MylabrisandPsalydolyttaspp.) varied between 0 and 50% for the four dominant grasshopper species. From 1993 and 1994 data, nymphal eclosion from egg pods damaged by meloids was significantly lower than emergence from undamaged egg pods. The hymenopterous parasitoidsScelio africanusRisbec andS. mauriticanusRisbec were reared from the four dominant grasshopper species and parasitism levels of 0.0–3.3% were recorded from these hosts. There were significant differences in nymphal emergences between parasitized and unparasitized egg pods ofH. daganensis.
Volatile substances evoking orientation in the predatory flowerbugAnthocoris nemorum(Heteroptera: Anthocoridae)
Authors: Dwumfour Edward F. 
Published: July 2009

AbstractChemical signals produced by leaves of stinging nettle (Urtica dioica), goat willow (Salix caprea) and tomato (Lycopersicon esculentum) attractedAnthocoris nemorumLinnaeus in a Y-tube plexiglass-walled olfactometer.A. nemorumreacted to odours of chloroform extracts of tomato foliage but not to water or methanol extracts. On the other hand, methanol or water extract ofU. dioicaattractedA. nemorum, but it was not attracted to chloroform soluble fractions of this plant. AdultA. nemorumcould not distinguish between odour released by the aphidsMyzus persicae(Sulzer) orBrevicoryne brassicaeLinnaeus (Homoptera: Aphididae) and leaf odours emitted by Brussels sprout (Brassica oleracea). However,A. nemorumreacted to and distinguished between odours coming from eitherTetranychus urticaeKoch orT. cinnabarinusBoisduval (Acari: Tetranychidae) and from clean French bean (Phaseolus vulgaris) leaves.
The influence of Dolichoderus thoracicus (Hymenoptera: Formicidae) on losses due to Helopeltis theivora (Heteroptera: Miridae), black pod disease, and mammalian pests in cocoa in Malaysia
Authors: Khoo K.C. , Ho C.T. 
Published: July 2009

AbstractThe influence of the black cocoa ant Dolichoderus thoracicus (Smith) on losses due to the mirid Helopeltis theivora Waterhouse, black pod disease (caused by Phytophthora palmivora (Peronosporales)) and mammalian pests (rats, squirrels and civet cats) was studied over a two-year period in two separate fields of cocoa. Both fields initially had high D. thoracicus activity. In each field, ant-scarce plots were created by treating these plots with insecticides; ant-abundant plots existed where the plots were left untreated. An abundance of D. thoracicus clearly had a negative effect on numbers of mirids, with respectively 380 and 2222% more nymphs and adults being recorded in the ant-scarce than in the ant-abundant plots over the two-year period. An abundance of D. thoracicus did not increase black pod incidence: on the contrary it reduced incidence of the disease in both fields. The number of rat-damaged pods in ant-scarce plots was significantly higher than in ant-abundant plots in one of the fields but no significant difference was detected in the other. Regarding number of pods lost to squirrels and civet cats, no significant difference between ant-scarce and ant-abundant plots was obtained for both fields; the losses to either of these mammalian pests were extremely low. The number of healthy ripe pods in ant-abundant plots was 40.4 and 32.1% higher than in ant-scarce plots in the two fields, these increases being ascribed to protection from H. theivora damage by D. thoracicus.
Evaluation of the toxicity and sublethal effects of lambda-cyhalothrin against horse flies (Diptera: Tabanidae) via bioassays and exposure to treated hosts
Authors: Leprince D.J. , Hribar L.J. , Foil L.D. 
Published: July 2009

AbstractMortality ofTabanus fuscicostatusHine females, engorged to repletion on bullocks treated with lambda-cyhalothrin impregnated ear tags, or placed on treated bullocks for periods of 15, 30, 45 or 60 s but not allowed to feed, was equal to or greater than 96%, while from 0% to 8% mortality was observed for controls. Average feeding time was significantly lower inT. fuscicostatusfed on treated bullocks (33%) than in flies fed on control bullocks, but average engorged weight was not significantly different between treatments. Mortality ofT. americanusForster females, placed on the backs of treated bullocks but not allowed to feed for periods of 15, 30, 45 or 60 s, was 16%, 44%, 76% and 100%, respectively. Results of bioassays in which flies were exposed to treated filter paper (LC50) or were topically treated (LD50) are presented per fly and per weight forT. fuscicostatusandT. lineolacomplex.
A model to predict the incubation and nymphal development periods of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)
Authors: Reus J.A.W.A. , Symmons P.M. 
Published: July 2009

AbstractA model has been developed which estimates the egg and nymphal development periods of the desert locust Schistocerca gregaria (Forskål). The model uses long-term monthly mean temperatures from a number of weather stations in the desert locust area. The computer program calculates the daily mean temperature and the daily related amount of development. It then accumulates the percentage of development estimated on successive days until the total reaches or exceeds 100. The model can be started on any day of the year at any given development stage and it can calculate development backwards in time as well as forwards. The model should be a useful aid in forecasting desert locust population developments and for the planning of surveys.
Improved persistence of insecticide deposits on targets for controlling Glossina pallidipes (Diptera: Glossinidae)
Authors: Torr S.J. , Holloway M.T.P. , Vale G.A. 
Published: July 2009

AbstractDeposits of deltamethrin suspension concentrate (s.c.) on Terylene net and cotton cloth were bioassayed in Zimbabwe by exposing them to fed, female Glossina pallidipes Austen, using a 45 s contact with cloth and a brief collision with net. On textured yarn net, the effective life of deposits produced from immersion in 0.1% deltamethrin was longer than on flat yarn net, apparently because the textured net held more insecticide and the insecticide was lost more slowly. The addition of an absorber for ultra-violet light (0.1% 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid) did not significantly extend the effective life of deltamethrin deposits on cloth or net. Applying deltamethrin s.c. as a 0.6% suspension to cotton cloth produced mortalities of <90% for 300 days. Applications of 0.8% deltamethrin on cotton cloth and textured net produced mortalities of <70% for 12–16 months and 9 months, respectively, compared to 4–10 months and 5–7 months, respectively for applications of 0.1% deltamethrin. Chemical analyses indicated that the longer effective life of the 0.6–0.8% was due to a higher initial amount of insecticide and a lower rate of loss. It is suggested that for controlling tsetse in southern Africa, all-cloth targets sprayed with 0.6% deltamethrin s.c. will have an effective life of ca. one year.
Second Report of the Tsetse-fly Investigation in the Northern Provinces of Nigeria
Authors: Lloyd Llewellyn , Johnson W. B. , Young W. A. , Morrison H. 
Published: July 2009

This report contains a record of the trypanosome infections, food and breeding of G. morsitans and G. tachinoides obtained by examining the flies at various foci over a period of fourteen months.It confirms the fact that the breeding of both species is practically confined to the dry season and follows a period of increased food supply. G. tachinoides is well fed through the rains, except in one month of flood, and starts breeding as soon as the rains cease, owing to its habit of feeding on reptiles. G. morsitans starts free breeding about six weeks later, as its increased food supply is due to the ungulates becoming more available.G. morsitans does not feed on reptiles, but in times of hunger draws a proportion of its food from birds, the largest proportion recorded being 17 per cent, in one month at one focus. It draws the bulk of its food in this locality from small antelope, large game being scarce. G. tachinoides is much less specialised in its diet, and in the wet season nearly one-fifth of its food was drawn from a group of animals which included man, monkey and dog.The infection of the flies with T. vivax and T. congolense bears a close relation to the amount of blood obtained from antelope, and consequently morsitans is in general nearly four times as heavily infected as tachinoides. Infections with T. brucei and T. gambiense are scarce in this locality. Trypanosome infection rises just before the main breeding season in morsitans in all localities and in tachinoides in places where the fly is largely a mammal feeder. The proportional infection in general falls in the season of most rapid breeding, owing to masking of the actual rise by the number of young flies examined. It rises rapidly when breeding ceases. The total infection is reduced when fly food is hard to obtain, in the time of long grass and flood, owing to T. vivax infections dying out when the flies are starved.It is shown that in some cases T. grayi may be obtained by tachinoides when it feeds on Varanus, and a somewhat similar infection in the laboratory may be obtained by feeding the flies on toads.It is shown that in some cases T. grayi may be obtained by tachinoides when it feeds on Varanus, and a somewhat similar infection in the laboratory may be obtained by feeding the flies on toads.There is just an indication that postponement of grass burning may interfere with the free breeding of morsitans and in some cases that of tachinoides. This possibility is to be tested.The experiment of excluding game and pig from one of the dry season foci of the flies by means of fencing will be carried out.
The Control of Chafer Grubs (Schizonycha Sp., Coleoptera, Melolonthinae) in the Sudan
Authors: Pollard D. G. 
Published: July 2009

Schizonycha larvae, of a species that cannot yet be named with certainty, are a serious pest of “lubia” (Dolichos lablab) and “dura” (Sorghum vulgare) in the Sudan Gezira. Damage from these grubs has seriously reduced lubia yields at the Gezira Research Farm during the 1946–52 seasons. Soil application of BHC, at rates between 10 and 40 gm. γ isomer per feddan (1·038 acre) give excellent control of this pest on lubia. Application with the seed at the time of sowing (in effect, by drilling) is, in general, more effective than broadcasting or applying the insecticide along the ridges. Seed dressings appear to be ineffective for control, with lubia.Population estimates show that γ BHC does not kill Schizonycha larvae but repels them or prevents feeding. The larvae occur in the soil to a maximum depth of 60 cm., and are concentrated around the plant roots. The mean depth varies with time of year, and probably with type of plant, between 15 and 30 cm. The mean depth of the pupa is 15 cm.; this does not appear to be influenced by BHC.Larvae are widely distributed in the Gezira but are most abundant in the South and Centre Groups of the Scheme. There is evidence that, where chafer larvae and termites are associated with groundnuts, the chafer larvae are responsible for initiating damage while the termites are secondary invaders. The beneficial effect of a good lubia crop (resulting from BHC application) is reflected in the cotton crop two years later.
Large-scale Spraying of Cotton in the Gash Delta in eastern Sudan
Authors: Joyce R. J. V. 
Published: July 2009

Following increased yields of cotton in the Sudan Gezira by DDT spraying, during the 1952/53 season 22,300 and 6,700 feddans of X1730A cotton were sprayed once and twice, respectively, in the Gash Delta of eastern Sudan, where nearly 60,000 feddans were grown under controlled flush irrigation. Each spray consisted of 1 lb. technical DDT per feddan and was applied by aircraft in 2 gals, of spray per feddan.Systematic observations were made on the incidence of cotton pests in 30 observation stations scattered throughout the Gash Delta, such stations being selected more or less at random from cotton sprayed once and twice and unsprayed, ten amongst each of these three treatments.A single DDT spray applied 50–70 days after sowing gave entirely satisfactory control of the Jassid, Empoasca lybica (de Berg.), and the thrips, Hercothrips fumipennis Bagn. & Cam. and H. sudanensis Bagn. & Cam., throughout the growth of the crop. There was little lasting control of the flea-beetle, Podagrica puncticollis Weise. The second spray, applied 70–90 days later, had little effect on any of these pests which were then present in low numbers.The incidence of bollworms was observed between December and March, covering the important fruiting period. During these months, over 70 per cent, more larvae of Diparopsis watersi (Roths.) and 40 per cent, more larvae of Earias insulana (Boisd.) were observed on sprayed than on unsprayed cotton. Significantly more larvae of D. watersi were recorded on cotton sprayed twice than sprayed once; conversely, significantly fewer larvae of E. insulana were recorded on twice- than on once-sprayed cotton. Moreover the estimated total number of fruits damaged by or shed in association with bollworm attack between January and March was over 30 per cent, greater, and nearly 30 per cent, more bollworm damage to nearly mature bolls was recorded between December and March, on sprayed than on unsprayed cotton.Yields of seed cotton were significantly less from twice-sprayed than from the other treatments. Once-sprayed cotton yielded less but not significantly so, than unsprayed cotton. Yield was negatively correlated with the number of sprays but the correlation coefficient just failed to reach significance.Further analysis of the data from stations where yield differences were most marked indicated that D. watersi lowered the yield potential of the crop as expressed by fruit production and retention, as a result of continuous shedding of the damaged fruit. Attack, however, was concentrated on cotton with the best yield potential. The effect of spraying was to increase the numbers of D. watersi and thus to give rise to excessive shedding, increased production of fruit primordia, an increased number of damaged bolls, and finally reduced yield.It is concluded that any benefits which the crop enjoyed, as a result of elimination of leaf-feeding insects by DDT spray, were completely lost through increased bollworm attack, which moreover reduced the yield below that of unsprayed cotton.
The Anopheline Mosquitos of the Sudan
Authors: Lewis D. J. 
Published: July 2009

The distribution of 29 species and three varieties ofAnophelesin the Sudan is shown on maps. Notes are given on each one with particular reference to distribution. Reasons are given for regardingA. rupicolusLewis as a synonym or local form ofA. rhodesiensisTheo. The former spread ofA. gambiaeGiles into the Palaearctic Region in Egypt is discussed, and notes are given on its distribution in the Wadi Halfa area.The general distribution of the Sudan Anophelines is discussed.Notes are given on malaria and onWuchereria bancrofti.
The Insect and Mite Fauna of a Scottish Flour Mill
Authors: Salmond K. F. 
Published: July 2009

Insects and mites collected within the various sections of a combined flour, oatmeal and provender mill are listed. The mill in question is one of the most northerly in Britain. Notes are given on the distribution, abundance and associations, within the mill, of the species recorded. The economic importance of those considered to be pests is assessed.The three most important pests were found to be Ephestia kuehniella Zell., Gnathocerus cornutus (F.) and Tribolium confusum Duv. It is suggested that Endrosis sarcitrella (L.), Tipnus unicolor (Pill. & Mitt.) and Cryptophagus cellaris (Scop.) might be included in the list of “ hardy ” insects given by Solomon & Adamson (1955) in their paper on the powers of survival of storage and domestic pests under winter conditions in Britain.
Some Mosquitos of the Sudan
Authors: Lewis D. J. 
Published: July 2009

One hundred and fifty six species, two subspecies and seven varieties of Culicidae are known to occur in the Sudan. The present paper shows the known distribution of members of the generaDixa, Chaoborus, Toxorhynchites, Harpa-gomyia, Hodgesia, Uranotaenia, Aëdomyia, Theobaldia, Ficalbia, TaeniorhynchusandEretmapodites, and includes taxonomic and other notes on several species.Some aspects of distribution are discussed, particularly the exchange of species between the Ethiopian and Palaearctic Regions in which movement has been mainly from the latter to the former.Brief notes are given on the practical importance of some species.
The Rice Root Aphid
Authors: Doncaster J. P. 
Published: July 2009

Independent discoveries of an Aphid attacking the roots of rice and other Gramineae in different parts of the world have led to its description under different names, and its affinity with other species has sometimes resulted in its confusion with them. The literature relating to the species is reviewed and it is shown that the correct name for it is Rhopalosiphum rufiabdominalis (Sasaki), of which Prunus is the primary host.What is believed to be a reasonably complete synonymy is given and this involves the sinking of the two genera Yamataphis Matsumura and Aresha Mordvilko as synonyms of Rhopalosiphum Koch because both of these genera were erected with the Rice Root Aphid as type. A species that was described as Yamataphis rhodesiensis Hall differs in too many respects to permit its inclusion in Rhopalosiphum and a new genus, Hallaphis, is erected for its reception.