bluuebunny/crossref_metadata_2025 huggingface dataset:
Description of the African rice gall midge, Orseolia oryzivora sp. n., with comparative notes on the ASian rice gall midge, O. oryzae (Wood-Mason) (Diptera: Cecidomyiidae)
Authors: Harris K. M , Gagné R. J.
Published: July 2009

The African rice gall midge, Orseolia oryzivora sp. n., is described and illustrated from adults of both sexes, larvae and pupae collected in West Africa. This species had previously been misidentified as O. oryzae (Wood-Mason), which is a major pest of rice in Asia, but the two species are morphologically distinct in the larval, pupal and adult stages. All available African material has been examined, and O. oryzivora is recorded from cultivated rice in Senegal, Upper Volta, Ivory Coast, Nigeria and the Sudan. Larvae and pupae collected from Paspalum in Upper Volta differ from typical O. oryzivora in some morphological characters and probably represent an undescribed species of Orseolia
Attempts to measure the influence of dung beetles (Coleoptera: Scarabaeidae) on the field mortality of the bush fly Musca vetustissima Walker (Diptera: Muscidae) in south-eastern Australia
Authors: Wallace M. M. H. , Tyndale-Biscoe M
Published: July 2009

The immature stages of Musca vetustissima Wlk. in dung pads in south-eastern Australia suffered a high mortality through the actions of a complex array of dung organisms, including dung beetles (scarabaeids), predatory beetles (hydrophilids and histerids) and predatory mites (Macrocheles glaber (Müll.)). At times of high dung beetle numbers, it was possible to demonstrate a relationship between fly mortality and dung beetle numbers. Single-species dung beetle populations appeared to be as effective as multiple-species populations in reducing fly numbers, except that some benefit was derived from a combination of day- and night-flying species. When dung beetle numbers were low, their influence could not be measured because of the high mortalities already caused by the other dung fauna. It is suggested that in those circumstances any mortality caused by the dung beetles may simply have become substituted for an existing mortality caused by other fauna without adding to the total mortality.
Effects of ovarian condition on nesting behaviour in a brood-caring dung beetle, Copris diversus Waterhouse (Coleoptera: Scarabaeidae)
Authors: Tyndale Biscoe Marina
Published: July 2009

Copris diversus Waterh. is a brood-caring dung beetle from Africa, the females remaining in the nest with their brood balls until the young emerge. A technique was developed which allowed access to the nest without interrupting nesting behaviour, so that beetles and nest contents could be observed and dung could be added into or removed from the nest at specific times. At 27°C, if more dung was added to the nest in the first three days after the start of brood care, most beetles continued oviposition. Resorption of the terminal follicle started some time between the third and twelfth days of brood care, and while the terminal follicle was resorbing the beetles did not revert to breeding if supplied with additional dung. Subsequent follicles were also resorbed if brood care was allowed to continue beyond ten days, but their resorption did not impose a lengthy delay in breeding. Oviposition resumed 17 to 21 days after the start of brood care, irrespective of when the dung was added. Development of new follicles following follicle resorption took three to seven days, and thus the resorption of the terminal follicle must have taken about seven to fifteen days.
The effects of odours, wind direction and wind speed on the distribution of Glossina (Diptera: Glossinidae) and other insects near stationary targets
Authors: Vale G. A.
Published: July 2009

In studies in the Zambezi Valley of Zimbabwe, Glossina morsitans morsitans Westw. and G. pallidipes Aust. were captured on electric nets at various points around stationary targets. The distribution of flies was affected by wind direction, wind speed and the presence or absence of an attractant odour consisting of carbon dioxide and acetone. The distributions suggested that tsetse attracted to baits by visual stimuli alone fly first to a point just downwind of the baits, where the perception of odour is important in host recognition. Changes in the distribution of catches when odour was used suggested that the distributions could form useful indices of assaying attractant odours in the field. Data for Muscidae, Tabanidae, Asilidae and Hymenoptera are also presented.
Distribution, biology and host specificity ofCyrtobagous singularisHustache (Coleoptera: Curculionidae) for the biological control ofSalvinia molesta
Authors: Forno I. W. , Sands D. P. A. , Sexton W.
Published: July 2009

Cyrtobagous singularisHust. was recorded from Brazil, Paraguay, Uruguay and Argentina in association with six species ofSalvinia(aquatic ferns). Field observations and laboratory studies in Brazil and Australia showed thatC. singularisseverely damagedS. molestaand that the weevil is suitable as a control agent for this weed in tropical and subtropical areas in Australia. In host-specificity studies using 46 plant species that occur in Australia, development of the immature stages took place only onS. molesta. Minor leaf scarring occurred on sweet potato when in contact with water, but starvation tests excluded this plant as a possible terrestrial host. Adults fed, but were unable to reproduce, on water lettuce (Pistia stratiotes). The high degree of host specificity indicated that establishment of this weevil in Australia is without risk to non-target plants.C. singulariswas first released and became established in Australia in 1980.
Application of the FAO-recommended method for detecting insecticide resistance in Aphis jabae Scopoli, Sitobion avenae (F.), Metopolophium dirhodum (Walker) and Rhopalosiphum padi (L.) (Hemiptera: Aphididae)
Authors: Stribley M. F. , MOORES G. D. , DEVONSHIRE A. L. , SAWICKI R. M.
Published: July 2009

Baseline toxicity measurements established discriminating concentrations of pirimicarb and demeton-S-methyl guaranteed to kill susceptible examples of Aphis fabae Scop., Sitobion avenae (F.), Metopolophium dirhodum (Wlk.) and Rhopalosiphum padi (L.) in the dip-test, the FAO-recommended method for detecting resistance in aphids. There was no evidence for resistance to either insecticide in field-collected populations of aphids from various parts of the UK or amongst variants of S. avenae characterised by staining their esterases after electrophoresis. New, simple techniques for rearing large numbers of colonies of cereal aphids are described.
Field observations on competitive displacement, at the preimaginal stage, of Culex quinquefasciatus Say by Culex cinereus Theobald (Diptera: Culicidae) at the Kenya Coast
Authors: Subra R. , Dransfield R. D.
Published: July 2009

In certain areas of the Kenya coast, Culex quinquefasciatus Say is unable to maintain itself in breeding sites (flooded pit latrines) which it has to share with C. cinereus Theo. The pattern of settlement of the two species and the replacement of C. quinquefasciatus by C. cinereus were studied from May to November 1980 by monitoring newly emerged males as they departed from two breeding sites located in a small village near Mombasa. C. quinquefasciatus was the first species to be recorded from both sites, soon after they were flooded by the early rains. C. cinereus came later and did not increase markedly until after the late rains. The pattern of replacement of C. quinquefasciatus by C. cinereus was similar in the two breeding sites; the former species was unable to maintain itself once C. cinereus started to increase. Studies in another village showed that, after displacement, egg laying by C. quinquefasciatus continued but at a much reduced level. It is suggested that this is an example of competition-mediated succession occurring annually, with C. quinquefasciatus being better adapted to exploit rapidly the newly flooded sites but unable to sustain later competition from C. cinereus.
Reservoirs forAphidius erviHaliday (Hymenoptera: Aphidiidae), a polyphagous parasitoid of cereal aphids (Hemiptera: Aphididae)
Authors: Cameron P. J. , Powell W. , Loxdale H. D.
Published: July 2009

Aphidius erviHal. parasitised natural populations ofAcyrthosiphon pisum(Harris),Sitobion avenae(F.) andMicrolophium carnosum(Buckt.) in Britain but parasitised few examples ofS. avenaeplaced on trap plants in winter wheat, nettle-grass edge areas or lucerne-wheat strip crops. In laboratory experiments,Aphidius ervireared fromAcyrthosiphon pisumdid not parasitiseM. carnosum, and significantly fewer mummies were formed onS. avenaethan onA. pisum. After rearingAphidius ervifor 4–5 generations onS. avenae, similar numbers of mummies were formed on both hosts. The switch of hosts fromAcyrthosiphon pisumtoS. avenaewas associated with the loss of certain parasitoid esterase enzyme bands revealed following electrophoretic separation of parasitoid proteins. Slow adaptation to new aphid hosts by polyphagous parasitoids such asAphidius ervimay reduce the usefulness of reservoirs as a source of beneficial species.
Movement Patterns of the testse fly Glossina palpalis palpalis (Robineau-Desvoidy) (Dipter: Glossinidae) around villages in the pre-forest Zone of lvory Coast
Authors: Randolph Sarah E. , Rogers David J.
Published: July 2009

The movement patterns of Glossina palpalis palpalis (R.-D.) around villages in Ivory Coast were investigated by means of mark-release-recapture studies at two different sites. At one site, Congo Aboisso I, there appears to have been a single fly population based on the village, with an asymmetric ebb and flow of flies between the village and the surrounding bush; flies tended to remain in or around the village once they had arrived there. At the other site, Degbézéré, on the other hand, there were two populations, one centred on the village and the other on a nearby lake, with considerable exchange between the two. It is suggested that flies go to Degbézéré Village and remain there to feed, primarily on domestic pigs, and females return to the lake briefly to larviposit; males stay longer at the lake, perhaps to increase their chances of mating with emerging females. Long-distance movement of flies between villages, and also an analysis of the spatial pattern of fly movement between Congo Aboisso I and the surrounding bush, shows that human activity may affect the pattern of tsetse movement. Flight activity, and the consequent fly movement, was related to the nutritional status of the flies; males with greater fat content undertook more flight activity and thus tended to move further away from the village. The implications of these results for attempts at local trypanosomiasis control are discussed.
Nuclear magnetic resonance spectroscopy for studying the development and detection of the grain weevil,Sitophilus granarius(L.) (Coleoptera: Curculionidae), within wheat kernels
Authors: Chambers J. , McKevitt N. J. , Stubbs M. R.
Published: July 2009

A novel non-destructive method was devised for studying the development of insects hidden within individual wheat grains using a standard nuclear magnetic resonance (NMR) spectrometer. The development ofSitophilus granarius(L.) at 25°C and 70% RH was studied from egg-laying to emergence by NMR, X-radiography and weighing. The results of the three methods correlated quite well. Neither the NMR nor the X-radiation appeared to harm the insects. The NMR method did not usually detect the insects until they were in the third larval instars, but after that the areas of the two NMR peaks observed with each infested grain followed a pattern which was readily interpreted in terms of the insect development. The major NMR peak was found to be due almost wholly to water and the minor peak to lipid, and the size of the major peak obtained with adults was close to that expected on the basis of their water content. The movement of some of the insects within the grains was observed for short periods and appeared to be characteristic of each developmental stage. Preliminary work with a less sophisticated NMR machine showed that it is possible in a single scan to detect ten grains infested withS. granariuslarvae in a batch of 500 grains, but further work is required to see whether single eggs can be detected. The results obtained in this study were sufficiently encouraging for a wide variety of other areas to be suggested in which use of NMR might help to solve some entomological problems.
Variability of vigour between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) and its implications for laboratory experimentation
Authors: Lenz M.
Published: July 2009

Groups of Coptotermes acinaciformis (Froggatt) originating from six colonies, three taken from each of two widely separated localities in northern Australia (Townsville and Darwin), were kept at population densities of 0·005, 0·001 or 0·020 g termites/ml. Survival and wood consumption of the groups after eight weeks followed a similar pattern in the colonies from both collection areas. Groups exhibited least vigour at the lowest population density, most vigour at the middle density and slightly less than maximum vigour at the highest density. However, the actual values for survival and wood consumption varied widely between colonies, irrespective of their origin. The implications of these and related results for laboratory experiments which rely on survival and wood consumption as indicators of termite vigour are discussed.
Genetic factors controlling flight performance and migration in the African armyworm moth,Spodoptera exempta(Walker) (Lepidoptera: Noctuidae)
Authors: Parker W. E. , Gatehouse A. G.
Published: July 2009

The existence of a genetic component in the determination of flight capacity suggested by the results of previous experiments on the effects of environmental factors on flight performance inSpodoptera exempta(Walker) was confirmed by successful selection for and against the capacity for prolonged flight. The results of selection experiments were consistent with those expected when a polygenic character is subjected to directional selection. Heritability estimates for flight duration were 0·4 for overall heritability (mean offspring on mid parent regression) and 0·5–0·9 for single sex offspring on female and male parent regressions, demonstrating that flight capacity has a substantial additive genetic component. Although there can be no doubt that genetic factors play a major role in the control of migration inS. exempta, it is not yet clear whether flight capacity is a continuously varying character or whether discontinuous variation in the form of a genetically controlled flight polymorphism is involved. It is suggested that the life-history strategy ofS. exemptais adapted to maximise dispersal in the rains when a massive extension of favourable habitat occurs, and to maintain populations in those habitats which remain favourable in the dry season. The present evidence suggests that this strategy is achieved by cyclic selection of genetically determined variability in potential flight capacity.
Baseline responses of United Kingdom field populations of Macrosiphum euphorbiae (Thomas) and Brevicoryne brassicae (L.) (Hemiptera: Aphididae) to demeton-S-methyl
Authors: Furk C. , Roberts H.
Published: July 2009

Baseline responses of United Kingdom field populations of Macrosiphum euphorbiae (Thomas) and Brevicoryne brassicae (L.) to demeton-S-methyl were investigated using the FAO-recommended dip-test bioassay. Dose-response lines were produced, and discriminating doses for the two species were derived from the results (320 and 500 mg a.i./litre, respectively) and validated by testing further field populations at those single doses. Of the 1620 individuals of M. euphorbiae and 330 of B. brassicae tested, none survived the discriminating doses.
Revisionary notes on the New World genera of cercopid froghoppers (Homoptera: Cercopoidea). III. The genus Isozulia
Authors: Fennah R. G.
Published: July 2009

The genus Isozulia is re-characterized and compared with Aeneolamia. Two species are transferred from Aeneolamia to become I. astralis (Distant) comb. n. and I. christenseni (Lallemand) comb. n., and I. flamen Fennah is reduced to a subspecies, I. astralis flamen, stat. n. Two populations from Ecuador and Peru are described as new species, I. minor sp. n. and I. charaxus sp. n., respectively, and a population of I. christenseni in Jujuy Province, Argentina, is recognised as a distinct subspecies, I. c. jujuyana subsp. n. Both this subspecies and I. minor are reported as attacking sugarcane.
A new species of Ferrisia (Hemiptera: Pseudococcidae) on cassava (Manihot esculenta) from Paraguay and on ragweed (Ambrosia tenuifolia) from Argentina
Authors: Williams D. J.
Published: July 2009

Ferrisia meridionalis sp. n. is described from Paraguay on cassava and from Argentina on ragweed (Ambrosia tenuifolia). Characters are given to separate it from F. virgata (Cockerell) with which it may easily be confused in life in South America on cassava.
Factors affecting resistance to insecticides in house-flies,Musca domesticaL. (Diptera: Muscidae). IV. The population biology of flies on animal farms in south-eastern England and its implications for the management of resistance
Authors: Denholm I. , Sawicki R. M. , Farnham A. W.
Published: July 2009

Ways in which the bionomics and dynamics of populations ofMusca domesticaL. can influence the development of insecticide resistance, and how resistance genes spread within and between farms was investigated in a three-year study of the biology and movement of flies on 63 pig-rearing farms in south-eastern England. House-flies survived winter only on 12 ‘overwintering’ farms where they bred in heated pig-rearing houses (‘closed buildings’) throughout the year. In late spring they appeared out doors, and their descendents founded populations on neighbouring ‘summer’ farms where pigs breed only in unheated (‘open’) buildings. There, flies reached peak numbers in August–September and died out by mid-November. Gene flow within and between farms was studied indirectly by mark-release-recapture of colour-marked adults, and directly by monitoring the diffusion of the visible marker genebwb(brown body) introduced into indigenous house-fly populations. Although movement between open buildings within a farm was unrestricted, dispersal between farms was limited, and gene flow between even adjacent closed buildings was indirect, and required more than one generation. Likewise, indirect and gradual gene flow during summer probably accounted for the similarity in type and frequency of other independent genetic markers of local overwintering populations. Thus closed buildings played a key role in house-fly ecology and population genetics. Unfortunately, control with persistent insecticides in these buildings ensures efficient resistance selection, ultimately resulting in its spread to all pig farms. Less selective control practices are needed at these sites.
Tanaostigmodes cajaninae LaSalle sp. n. (Hymenoptera: Tanaostigmatidae), a potential pest of pigeon pea in India
Authors: Lateef S. S. , Reed W. , LaSalle J.
Published: July 2009

Tanaostigmodes cajaninae LaSalle sp. n., the larvae of which feed in pods of pigeon pea (Cajanus cajan), is described. This insect, which also feeds on the weeds Atylosia spp. and Rhynchosia spp., has reached pest status on ICRISAT's research farm in Andhra Pradesh, India, where more than half of the pods on the late-maturing pigeon pea crops may be infested. However, surveys of the crops in farmers' fields in India showed that, although this insect is widespread, it is not yet a serious pest. The abnormal populations of this insect on the ICRISAT research farm appear to be associated with an abundance of its wild hosts, the availability of pigeon pea pods for many months in each year and the use of endosulfan, which does not control the pest but reduces its parasites. The potential for T. cajaninae to become a major pest in farmers' fields is discussed, and control measures are suggested.
Effects of temperature on the development of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae)
Authors: Miller Gareth W. , Isger Mark B.
Published: July 2009

The effect of constant and sinusoidally cycling temperatures on the durations of combined egg and larval development and of pupal development of Liriomyza trifolii (Burgess) was studied. The observed and estimated durations accorded well using 147·5 day-degrees above 10 1°C for eggs and larvae and 138·7 day-degrees above 10·8°C for pupae. A few pupae survived for 76 days in outdoor cages during a winter in southern England. Eggs hatched at 6–16°C (cycling), but larvae did not complete their development under this regime. Adults emerged from pupae at 6–16°C, and a few deformed adults emerged after 65 days at 11·5°C (constant). Some pupal development was detectable at 8°C. Pupae exposed to 1·1°C for 20 days all died, but some adults emerged at 14–26°C from pupae that had been kept at 1·1°C for 15 days.
Control of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in Egypt by mating disruption using hollow-fibre, laminate-flake and microencapsulated formulations of synthetic pheromone
Authors: Critchley B. R. , Campion D. G. , McVeigh L. J. , McVeigh E. M. , Cavanagh G. G. , Hosny M. M. , Nasr EL-Sayed A. , Khidr A. A. , Naguib M.
Published: July 2009

Hollow-fibre, laminate-flake and microencapsulated formulations of the synthetic sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-7, 11-hexadecadienyl acetate) of Pectinophora gossypiella (Saunders) were compared in large-scale mating disruption trials in Egypt in 1982. Fifty-hectare blocks of cotton were treated at regular intervals throughout the season with the formulated pheromone as the sole means of controlling the pest. The pheromone treatments were compared with conventional insecticide spray treatments in other 50-ha blocks of cotton sited in the same localities. Comparisons of numbers of infested flowers and green boils, open boll counts, crop development, yield of seed cotton, lint quality and seed damage in pheromone-and insecticide-treated blocks, showed that adequate levels of control were achieved using the pheromone formulations, which were equal in effect to the insecticide sprays. Beneficial insects were found in greater numbers in the pheromone-treated areas than in areas treated with insecticides.
Colony development and alate production in Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) on winter wheat
Authors: Cannon R. J. C.
Published: July 2009

An ecological study of summer populations of Metopolophium dirhodum (Walker) on winter wheat, was carried out near Bedford, UK, in 1978–80. Alate production (as percentages of alatiform fourth-instar nymphs) followed a consistent and synchronous three-phase pattern: with increases to 50% in early June in 1978–80 and 90% in late July in 1978–79. The proportions of winged offspring deposited by apterous parents also showed a similar increase, changing from 5% on 14–20 June to 91% on 5–11 July. Alate parents deposited mostly (75%) wingless offspring. Frequency distributions for nymph batch sizes were obtained for both morphs in 1979. Alate deposition was bimodally distributed. For apterous aphids, the fourth instar was the main dispersal stage. The numbers of adult apterae expressed as proportions of the total population were generally lower in 1979 than in 1978. The numbers of colonies increased sharply between 19 and 21 June in 1978 and 1979, and remained at similar levels to each other until at least 5 July. Colony and population numbers were highly significantly correlated over certain periods in 1978 and 1979. Colonies with >20 aphids increased sharply in numbers after 6 July, probably as a result of changing aptera dispersiveness. An estimate of mean colony size in 1979 showed a well-defined 14-day plateau phase. Changes in population alate production and changes in the proportions of winged offspring (from apterous parents) are discussed in relation to colony development. It is considered that increases in colony size produce colony-specific patterns of alate production.
An experimental evaluation of conventional control measures against the sheep tick, Ixodes ricinus (L.) (Acari: Ixodidae). II. The dynamics of the tick-host interaction
Authors: Randolph Sarah E. , Steele Gordon M.
Published: July 2009

The experimental manipulation of separate, but originally identical, populations of Ixodes ricinus (L.) by applying three conventional tick control measures in different enclosures on naturally infested moorland in Wales allowed the elements of the tick-host interaction to be analysed quantitatively and the effectiveness of the control methods to be compared. From the relationship between the sheep stocking density and the numbers of questing ticks picked up by fortnightly blanket-dragging in each enclosure, the death rate of ticks during their activity season and the rate of contact between sheep and ticks were calculated. From this, it was possible to investigate the effect of different stocking densities on the feeding success of ticks. A major factor determining the much lower contact rate for larvae than for nymphs was the different spatial distribution of questing ticks, clumped for larvae and random for nymphs. The non-random use by sheep of the three different vegetation zones in the paddock resulted in the highest contact rate between sheep and ticks in the pasture area, but tick survival was apparently highest in the bog area. Combining these factors resulted in the prediction that the bracken area was the least favourable habitat for ticks. In the two enclosures where the sheep were not treated with acaricide the mean tick loads on the sheep were similar, but the lower overall use of the pasture by the sheep in the low stocking density enclosure (2/ha) resulted in slightly lower tick loads there compared with those in the high stocking density enclosure (4/ha). The numbers of ticks counted in the second year showed that pasture spelling was the most effective control method, acaricide treatment was less effective, and the benefits of halving the stocking density were marginal. The implications of these results for control strategies are discussed.
Responses of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), to carbon dioxide and host odours. I. Activation
Authors: Warnes M. L. , Finlayson L. H.
Published: July 2009

Laboratory experiments were carried out to investigate the effect of carbon dioxide and breath odours on the flight activity of Stomoxys calcitrans (L.). The flies responded to an increase in carbon dioxide concentration by an increase in flight activity (measured as the number of flights or the number of take-offs). The extent of this response was dependent on the period of starvation before exposure and the level of the increase in the carbon dioxide concentration. Flies rapidly habituated or adapted to new levels of carbon dioxide. Expired human breath elicited a greater increase in flight activity than would be predicted from its carbon dioxide content, and it was shown that the increased activity was caused by breath odours acting synergistically with an increase in the carbon dioxide concentration.
Genetics of an esterase associated with resistance to organophosphorus insecticides in the sheep blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)
Authors: Hughes P. B. , Raftos D. A.
Published: July 2009

Electrophoresis was used to characterize the esterases in Lucilia cuprina (Wiedemann). Of the 16 esterase bands visualized, only one was associated with resistance to organophosphorus insecticides. In laboratory reference strains, the esterase E3 was consistently found in both susceptible and heterozygously resistant flies, but was absent from homozygously resistant flies. It was postulated that resistant flies possessed a non-staining form of E3, designated E3null. Genetic analyses mapped the locus for E3null to a position in the same region as the gene for organophosphorus resistance. No recombinants between the genes for resistance and E3null were detected. In field populations of L. cuprina from several areas in Australia, a close association was found between the frequency of E (0·97) and the proportion of flies resistant to organophosphorus insecticide (0·967). This association suggests that E3null represents the product of a major resistance gene in terms of the ‘mutant ali-esterase’ theory. E3 as found in susceptible blowflies, represents the ‘original’ ali-esterase, the gene for which mutated to one coding for E3null. This mutant enzyme can hydrolyse organophosphates more efficiently than E3 but has lost the ability to hydrolyse 1- and 2-naphthyl acetate (the substrates used to visualize the esterases after electrophoresis).
Pseudococcus mandio sp. n. (Hemiptera: Pseudococcidae) on cassava roots in Paraguay, Bolivia and Brazil
Authors: Williams D. J.
Published: July 2009

Pseudococcus mandio sp. n. is described from the roots of cassava in Paraguay, Bolivia and Brazil. In Paraguay, it is probably associated with wilting of the plant and, in common with most mealybugs, it appears to be a phloem-feeder. There is evidence of sufficient phloem in the roots, and this may be identical with the phloem of the stems. The mealybug is related to P. affinis (Maskell) in possessing swollen hind femora with numerous translucent pores, and discoidal pores around the eyes, but the oral rim ducts are either few or absent entirely.
The identity and distribution of the genus Maconellicoccus Ezzat (Hemiptera: Pseudococcidae) in africa
Authors: Williams D. J.
Published: July 2009

Since Maconellicoccus hirsutus (Green), a pest of many plants including Hibiscus, was introduced into Egypt in 1908, probably from the Oriental Region, it has spread to much of tropical Africa. There is little information available on its control, but the encyrtid Anagyrus kamali Moursi is known to give good control in Egypt. The ladybird Cryptolaemus montrouzieri Mulsant is a voracious feeder on M. hirsutus in Egypt, but it does not survive the Egyptian winter, although it may be useful in the tropical areas. M. perforatus (De Lotto) is synonymized with M. hirsutus, and the distribution and host-plants of this species in Africa are discussed. A lectotype is designated for M. ugandae (Laing), a species now known to occur throughout tropical Africa, especially on coffee and cocoa. It is illustrated and redescribed and compared with M. hirsutus. M. bardus De Lotto, known from South Africa only, is excluded from the study because it probably belongs to the genus Chorizococcus.
An indian tropiduchid planthopper Tambinia verticalis Distant (Hemiptera: Fulgoroidea) breeding on coconut in zanzibar
Authors: Wilson M. R.
Published: July 2009

Tambinia verticalis Distant, an Indian tropiduchid planthopper, has been found breeding on coconut in Zanzibar, Tanzania, and also in low numbers in mainland Africa. No Tambinia species has hitherto been recorded in Africa. A lectotype is designated for T. verticalis, and the species is redescribed and figured.
Ecology of the malaria vector Anopheles arabiensis Patton (Diptera: Culicidae) by the nile in northern Sudan
Authors: Dukeen Mustafa Y. H. , Omer S. M.
Published: July 2009

In order to understand how the malaria vector Anopheles arabiensis Patton exists in the extremely hot and arid environment (mean annual rainfall 21 mm) in Northern Province, Sudan, regular sampling from breeding places and resting sites was undertaken during 1978 and 1979 at four villages along the River Nile downstream (i.e. northwards) from Dongola. The population density of A. arabiensis was lowest during the flood season (July—October) and increased as the river flow decreased during November—June. Thus there was an inverse relationship between the Nile water level and A. arabiensis production. Prolific breeding in riverside pools was the main source of A. arabiensis as the river receded. During the annual flood, when riverside pools were all inundated, A. arabiensis continued breeding at low densities in sheltered sites such as wells and pits. Breeding also occurred in all months in association with the weed Potamogeton crispus in slow reaches of the river. Adult females fed regularly on blood, with gonotrophic concordance in all months, and there was no evidence of aestivation. Outdoor biting activity occurred throughout the night, with a peak between 2100 and 0500 h. Daytime searches indoors and outdoors indicated that resting females A. arabiensis are almost entirely endophilic in the study area.
Selection for malathion resistance in Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae): fitness values of resistant and susceptible phenotypes and their inclusion in a general model describing the spread of resistance
Authors: Muggleton John
Published: July 2009

A malathion-resistant strain of Oryzaephilus surinamensis (L.) was subjected to selection with malathion for ten generations at three doses, 65, 260 and 390 mg/m2. The relative fitness of the resistant homozygote, the heterozygote and the susceptible homozygote were estimated at each dose and in an untreated control population by comparing the change in frequency of the susceptible homozygote from generation to generation. In the absence of the insecticide, the resistant genotypes had a fitness coefficient of 0·82 compared to the susceptibles, whereas following selection at the highest dose of malathion, the fitness coefficient of the susceptible homozygote was 0 and that of the heterozygote 0·4, compared to the resistant homozygote. With selection at the highest dose of malathion, the frequency of the resistance gene rose from 0·5 to around 1·0 during the experiment, and this was accompanied by a 2·3-fold increase in the resistance factor at the ED50. A model is provided to show how the data collected in these experiments can be used to predict the increase in resistance under various treatment regimes. The model shows that although resistance would be delayed longest at the lowest dose, such a dose would fail to control the pest population. Using the data from these experiments, the model predicts that the best combination of control and delay of the spread of resistance would be achieved by using the highest dose of malathion while allowing the maximum acceptable proportion of beetles to remain untreated.
The activity of parasitoids (Hymenoptera: Braconidae) of cereal aphids (Hemiptera: Aphididae) in winter and spring in southern England
Authors: Vorley W. T.
Published: July 2009

Indirect and direct measures of parasitoid activity were taken in grassland and autumn-sown cereals in southern England between 1979 and 1981. Studies of anholocyclic aphid populations in the winter months were followed through to parasitism of the main pest species, Sitobion avenae (F.), during the period of population increase in April and May. Aphidius spp. parasitized artificially-established colonies of cereal aphids in ryegrass in every month between December and May of both seasons, but there was no Aphidius activity until March-April in winter cereals sown early enough to receive an autumn input of aphids and parasitoids, apparently due to the small amount of physiological time that accumulates before temperatures drop in the winter months. A. rhopalosiphi De Stefani Perez and A. picipes (Nees) were completely dominant over other parasitoid species in the winter and spring period. Natural populations of Aphidius adults and parasitized aphids were low (<2/m2) in both winters, and percentage parasitism of S. avenae measured by dissection in March and April did not exceed 11·7%. Rates of S. avenae parasitism in many winter wheat fields peaked in May, before the peak and rapid decline in aphid populations. The significance of winter and spring parasitoid activity to the survival of the parasitoid and effects on pest aphid peaks are discussed.
Comparative study of resistance to organophosphate and carbamate insecticides in four strains of theCulex pipiensL. complex (Diptera: Culicidae)
Authors: Tang Z. H. , Wood R. J.
Published: July 2009

Five strains ofCulex pipiensL. (four resistant and one susceptible) were compared at the fourth larval instar for tolerance to organophosphate, carbamate and pyrethroid insecticides, with and without the addition of three synergists (piperonyl butoxide, triphenyl phosphate (TPP) andS, S, S-tributyl phosphorotrithiote (TBPT)). The DAR/D strain from Tanzania showed the highest levels and broadest range of resistance (temephos 37 ×, malathion 579×, propoxur 3032× and permethrin 100×). A strain from Rangoon and two from France (S54, BLEUET) showed lower resistance, restricted to organophosphates. Temephos and malathion resistance in the RANGOON strain was strongly inhibited by TBPT but not by TPP or piperonyl butoxide. Temephos and permethrin resistance in the DAR/D strain was slightly inhibited by TBPT and permethrin resistance by piperonyl butoxide. The DAR/D, RANGOON and CfCA (susceptible) strains were also compared for general esterase activity and phosphatase activity, both of which were higher in the resistant strains. It is concluded that resistance in RANGOON is associated with high production of an esterase sensitive to inhibition by TBPT but with little or no sensitivity to TPP, resembling but not identical in properties with the enzyme in strain S54 investigated earlier. Resistance in DAR/D was also associated with some increase in esterase activity, but the basis of resistance was different from that in S54 and RANGOON, having a much lower sensitivity to inhibition by TBPT.
Effects of ageing and nutrition on the reproductive system of Samea multiplicalis Guenée (Lepidoptera: Pyralidae)
Authors: Taylor M. F. J. , Sands D. P. A.
Published: July 2009

The influence of ageing, larval dietary nitrogen and adult carbohydrate diets on development of the male and female reproductive systems of Samea multiplicalis Guenée are described. Mature oocytes appeared in the ovarioles of one-day-old females and remained constant in number from one to three days after eclosion. Females from larvae that fed on plants of Salvinia molesta matured fewer oocytes (65 vs. 138) when the plants had lower (0·94% vs. 2·74%) levels of nitrogen. Resorbing oocytes were identified in the ovarioles of females 1–3 days old. The proportion of females with resorbing oocytes increased with age but not with larval dietary nutrition. Following high levels of larval dietary nitrogen, the seminal vesicles in males increased in length, while their width increased with age but not with diet. High levels of larval dietary nitrogen and an intake of adult dietary carbohydrate were both necessary for maximum fecundity. Higher levels of larval dietary nitrogen resulted in greater adult size, as measured by forewing length.
Differentiation ofanopheles culicifaciesGiles (Diptera: Culicidae) sibling species by analysis of cuticular components
Authors: Milligan P. J. M. , Phillips A. , Molyneux D. H. , Subbarao S. K. , White G. B.
Published: July 2009

Cuticular wax was extracted from adult females ofAnopheles culicifaciesGiles and analysed by gas liquid chromatography. The flies were taken from pure cage stocks of three sibling species: 56 individuals of species A, 43 of species B and 51 of species C. The three cytospecies were found to be significantly different in their cuticular hydrocarbon composition by a multivariate analysis of variance. Using discriminant analysis, each cytospecies was characterized by the amounts of C25-C33 hydrocarbons extracted from the cuticle, allowing criteria to be established for the identification of flies. By these criteria, specimens from stocks of known identity were allocated to the correct group with a high success rate. These results may reflect ecological differences among the sibling species.
Studies of the mortality of Locusta migratoria (L.) treated with a polyhedrosis virus from the grasshopper Caledia captiva(F.) (Orthoptera: Acrididae)
Authors: Cologan D. J.
Published: July 2009

Preparations made from the Australian acridine grasshopper Caledia captiva (F.) that contained a recently discovered cytoplasmic polyhedrosis virus (CPV) were used to treat Locusta migratoria (L.). Feeding of the locusts with the preparations caused a significant increase in mortality. Although these deaths were associated with the viral treatment, their ultimate cause appeared to be uncontrolled proliferation of a bacterium, which is probably a strain of Enterobacter cloacae and which is usually found in locusts without ill effect. Four areas are identified where further work is necessary before the potential of the C. captiva CPV as an agent for the biological control of L. migratoria can be assessed.
Natural enemies of the african armyworm,Spodoptera exempta(Walker) (Lepidoptera: Noctuidae), in Tanzania
Authors: Merrett P. J.
Published: July 2009

In Tanzania, residual populations ofSpodoptera exempta(Walker) may persist in highlands and river valleys, giving rise to the first outbreaks in the rainy season. To examine whether parasitoids could be a key factor in maintaining these populations at low density, samples were taken during outbreaks in eastern and north-eastern Tanzania from 1980 to 1984. Parasitism was high (around 50%) in the low density samples (below 25 larvae/m2) and low (below 17%) in the highest density ones (about 250–1200 larvae/m2). The number of outbreaks reported from the same administrative district as the sample site, and concurrent with it, was inversely related to parasitism level. The directly density dependent relationship between percentage parasitism and host density at lower densities, and the inversely density dependent one at higher densities, is similar to that found in parasitoid complexes of other Lepidoptera. Parasitoids in the rare braconid genusMeteorideawere recorded attackingS. exempta; this is the first published record from mainland Africa.
Rastrococcus invadens sp. n. (Hemiptera: Pseudococcidae) introduced from the Oriental Region to West Africa and causing damage to mango, citrus and other trees
Authors: Williams D. J.
Published: July 2009

Rastrococcus invadens sp. n. has been accidentally introduced to West Africa where it is causing considerable damage to many plants, especially mango and citrus, in Togo and Ghana. The origin of the mealybug is the Oriental Region, where it is known from a wide area, but it has always been mistaken for R. spinosus (Robinson), a closely related species. Serious outbreaks on mango in some areas of the Oriental Region suggest recent introductions also, although records from other parts of the Oriental Region are as early as 1900.
Geographic variability in demographic performance of the potato moth, Phthorimaea operculella(Zeller) (Lepidoptera: Gelechiidae), in Australia
Authors: Briese D. T.
Published: July 2009

Measurements of several parameters of demographic performance for 16 field-derived Australian populations of Phthorimaea operculella (Zeller) were obtained under laboratory conditions. Fecundity, female weight and low temperature development rates were the most important parameters contributing to differences between populations. It is suggested that the increased fecundity and female weights found in warmer regions may be selected for in part by the continuous high mortality imposed by parasitoids, which have a reduced impact in the colder parts of P. operculella's range. A more rapid development rate in populations from colder areas is probably due to selection for a decreased lower threshold temperature in these areas, indicating better survival characteristics under cold conditions.
The ecology of lutzomyia umbratilis Ward & Fraiha (Diptera: Psychodidae), the major vector to man of Leishmania braziliensis guyanensis in north-eastern Amazonian brazil
Authors: Ready P. D. , Lainson R. , Shaw J. J. , Ward R. D.
Published: July 2009

A description is given of the phlebotomine faunas of forests in north Pará State, Amazonian Brazil, that are endemic for ‘pian bois’-type dermal leishmaniasis of man caused by Leishmania braziliensis guyanensis. As judged by collections from human baits, mammal-baited traps, CDC miniature light traps and from various resting sites, only the females of Lutzomyia umbratilis Ward & Fraiha have the habits (both arboreal and terrestrial) and abundance (periodic, seasonal and spatial) consistent with being a major vector to man of Leishmania b. guyanensis. Man is at risk of infection by the bite of Lutzomyia umbratilis at any time of the year if he disturbs the females from their daytime resting sites (on and around the bases of the larger forest trees) or if he remains in the forest between late afternoon and dawn (1700–0700 h).
Incidence and distribution of insecticide-resistant strains of Myzus persicae (Sulzer) (Hemiptera: Aphididae) in england and wales in 1980–84
Authors: Furk C.
Published: July 2009

Between 1980 and 1984, a total of 2710 individuals of Myzus persicae (Sulzer) collected in England and Wales was tested by electrophoresis and classified as being susceptible (S), moderately resistant (R1) or strongly resistant (R2) to insecticides. Aphids sampled from oilseed rape from the Midlands and western and eastern England had the lowest frequencies of S and the highest frequencies of R1 aphids. Over all crops, eastern England had a low frequency of S and a high frequency of R1 aphids. R2 aphids were more common in northern England than in other areas of England and Wales but only on potatoes. There was no evidence of any increase in the incidence of resistant aphids (both R1 and R2) since a previous survey in 1976. Possible reasons for the distribution patterns of the three aphid types are discussed.
Control of the grass grub, Costelytra zealandica (white) (Coleoptera: Scarabaeidae), by application of the bacteria Serratia spp. causing honey disease
Authors: Jackson T. A. , Pearson J. F. , Stucki G.
Published: July 2009

Isolates of Serratia marinorubra and S. liquefaciens pathogenic for Costelytra zealandica (White) were artificially cultured and applied to field populations of larvae of C. zealandica in New Zealand in the late summer and autumn of 1984. In four trials, when bacteria were applied from February to late March, high levels of disease transmission were recorded. Three months after application, significant (P<0·05) reductions of 30–59% in the larval populations were obtained, and 47% of the remaining larvae in the treated plots were diseased, suggesting the long-term effect would be greater. Treatment resulted in a 30% increase in dry matter production in the pastures. There was no consistent difference between the bacterial isolates tested. Application of the bacteria in May had no effect on the larvae, suggesting that they were no longer susceptible. It is concluded that these pathogenic isolates should be developed further as microbial insecticides for control of C. zealandica.