bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of resistance, cross-resistance and synergism of abamectin and teflubenzuron in a multi-resistant field population of Plutella xylostella (Lepidoptera: Plutellidae)
Authors: Iqbal M. , Wright D.J.
Published: July 2009

The efficacy of abamectin (AgrimecR) and teflubenzuron (NomoltR) was assessed by leaf-dip bioassay against larvae of the diamondback moth, Plutella xylostella Linnaeus from a population (SERD3) collected originally in lowland Malaysia in December 1994. Evidence for resistance to both abamectin and teflubenzuron was found in the F7 generation (LC50 ratio of 60 and 24 respectively compared with a laboratory, insecticide-susceptible strain). Selection of sub-populations of SERD3 (F7–F9) with abamectin and teflubenzuron increased the LC50 ratio to 220 and 360 respectively and estimates of realized heritability [h2] were high (c. 0.8 and 0.9) for both compounds. There was no cross-resistance between these compounds in the abamectin and teflubenzuron-selected sub-populations but some indication of negatively-correlated resistance. Topical application of the synergists piperonyl butoxide, S,S,S-tributylphosphorotrithioate and maleic acid diethyl ester to the laboratory strain had no significant effect on the toxicity of abamectin or teflubenzuron in subsequent leaf-dip assays. In contrast, pre-treatment with piperonyl butoxide and S,S,S-tributylphosphorotrithioate significantly increased the toxicity of abamectin (c. 4- and 3-fold) and teflubenzuron (c. 7- and 19-fold) in the abamectin and teflubenzuron-selected sub-populations of SERD3, suggesting that microsomal monoxygenases and/or esterases may be involved in resistance. Pre-treatment with maleic acid diethyl ester only increased the toxicity of abamectin by c. 2-fold and had no significant effect on the toxicity of teflubenzuron, providing limited evidence for the involvement of glutathione-S-transferases in resistance to the former compound alone.
Geographic variation in host selection behaviour and reproductive success in the stemborer parasitoidCotesia flavipes(Hymenoptera: Braconidae)
Authors: Potting R.P.J. , Vet L.E.M , Overholt W.A
Published: July 2009

Local parasitoid populations may be adapted to their sympatric major plant host complex. Parasitoid strains may thus differ in their propensity to search for a particular micro-habitat or host or they may differ in their physiological compatibility with particular plant or host species.Cotesia flavipesCameron, a larval parasitoid used worldwide in biological control against tropical stemborers, has a wide host range in diverse habitats. The existence of plant and/or host specific strains inC. flavipeshas been postulated. To provide insight into the existence of strains inC. flavipes, we compared the plant/host complex selection behaviour, and physiological compatibility with different stemborers, of six different geographic strains ofC. flavipesthat differed in the plant/host complex they were obtained from. The results of the host selection experiments indicate that there is no intraspecific variation in host selection behaviour amongC. flavipesstrains. However, our comparative experiments show variation in reproductive success among strains. The most significant result was that the strain with the longest period of co-existence with the new hostDiatraea saccharalisFabricius had the highest reproductive success on this host species. We argue that the reported existence ofC. flavipesstrains is based not on differences in host selection behaviour, but on differences in physiological compatibility between local parasitoid and host population.
Canopy knockdown of arthropods in exotic plantations and natural forest in Sabah, north-east Borneo, using insecticidal mist-blowing
Authors: Chey V.K. , Holloway J.D. , Hambler C. , Speight M.R.
Published: July 2009

Canopy knockdown of arthropods using mist-blowing was carried out in Brumas, Sabah (north-east Borneo), in plantations of exotic (non-indigenous) tree species (Acacia mangium, Eucalyptus deglupta, Gmelina arborea, Paraserianthes[=Albizia]falcataria, andPinus caribaea), plus secondary natural forest and dense understorey withinE. degluptastands. Each habitat had three 1 m2samples taken four times in one year. The average arthropod species richness within the stands of the exotic tree species ranged from 27 inE. deglupta, to 68 in natural, secondary forest. The total number of individuals caught ranged from 137 in G.arboreato 1628 in secondary forest. The dense and plant-species rich understorey withinE. degluptastands yielded both higher numbers of species and individuals than the eucalypt trees themselves, indicating the importance of allowing the development of a luxuriant understorey for the enhancement of conservation and biodiversity. Though arthropod biodiversity is reduced by the conversion of tropical forests to plantations, abundance and richness are still substantial in the latter habitats.
Biological control ofBemisia argentifolii(Hemiptera: Aleyrodidae) on poinsettia with inundative releases ofEretmocerus eremicus(Hymenoptera: Aphelinidae): do release rates affect parasitism?
Authors: Hoddle M.S. , Van Driesche R.G. , Sanderson J.P. , Minkenberg O.P.J.M.
Published: July 2009

The effectiveness of inundative releases of the parasitoidEretmocerus eremicusn. sp. Rose & Zolnerowich for control ofBemisia argentifoliiBellows & Perring on poinsettia in replicated experimental greenhouses was determined. We evaluated two release rates ofE. eremicus:a low release rate (one female per plant per week, released in two greenhouses, in spring 1995) and a high release rate (three females per plant per week, released in two greenhouses, in spring 1994), each over a 14 week growing season. Each release trial had either one (1995) or two (1994) control greenhouses in whichB. argentifoliideveloped on poinsettia in the absence ofE. eremicus. Life-tables were constructed forB. argentifoliiin the presence and absence ofE. eremicusby using a photographic technique to follow cohorts of whiteflies on poinsettia leaves. Weekly population counts of whiteflies were also made. In the absence ofE. eremicus, egg to adult survivorship ofB. argentifoliion poinsettia was 75–81%. At the low release rate, egg to adult survivorship ofB. argentifoliiwas 12% and parasitism was 34%. At the high release rate, egg to adult survivorship ofB. argentifoliiwas 0.9% and parasitism was 10%. The average net reproductive rates (Ro) for populations ofB. argentifoliiin the absence ofE. eremicusranged from 20.5 to 26.1, indicating a rapidly increasing population density. Net reproductive rates for whitefly populations subject to parasitoid releases were 3.7 in the low release rate greenhouses, and 0.25 in the high release rate greenhouses, indicating substantially reducedB. argentifoliipopulation growth. At week 14 of the trial, densities of immature whiteflies were lower in greenhouses at the low release rate when compared to the high release rate greenhouses. This was attributed to high levels of in-house reproduction by parasitoids at the low release rate.
Population density, development and behaviour of Diopsis longicornis and D. apicalis (Diptera: Diopsidae) on rice in the Republic of Guinée
Authors: Chiasson H. , Hill S.B.
Published: July 2009

The behaviour and pest status of the rice stem borers Diopsis longicornis Macquart and D. apicalis Dalman were investigated in the Republic of Guinée, particularly during the dry season. The variables were direct seeded and transplanted rice, and three (1988, 1989) and four (1987) planting dates. Transplanted rice was damaged nearly three times more than direct seeded rice in the dry season, but no significant difference was detected during the wet season. As previously observed in other West African countries, D.apicalis only occasionally damages rice in Guinée. Contrary to findings elsewhere, D. longicornis was not an important pest of Guinean rice, infesting only 5% and 3% of stems over the three dry and the two wet seasons, respectively. However, year round rice production could promote build up of the diopsid population if dry season planting is not sufficiently delayed (45 days) after the last rains of the wet season.
Interference by ants in biological control of the cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) in Ghana
Authors: Cudjoe A. R. , Neuenschwander P. , Copland M. J. W.
Published: July 2009

In surveys of cassava fields in the coastal savanna and rain forest zones of Ghana, eight species of ants, mostly in the genera Camponotus, Crematogaster and Pheidole (Hymenoptera: Formicidae), were found attending cassava mealybug, Phenacoccus manihoti Matile-Ferrero. Ant densities were much higher in the rain forest than in the savanna and, in most zones, positively correlated to mealybug population densities. Pheidole megacephala (Fabricius) was the only species more abundant in the interior of fields, whereas the other species preferred the edges of fields or, like Camponotus spp., did not respond to edge effects. Weediness of the fields did not clearly influence the presence of ants. Crematogaster sp. and P. megacephala spent most of the time on cassava tips, where they built carton tents. Ants of the three genera reduced parasitism rates by the exotic Epidinocarsis lopezi (De Santis) (Hymenoptera: Encyrtidae) to half, compared to the rates observed on mealybug colonies of equal size that were not attended. Hyperparasitism by Prochiloneurus insolitus (Alam) (Hymenoptera: Encyrtidae) and Chartocerus hyalipennis Hayat (Hymenoptera: Signiphoridae) and predation by the indigenous Exochomus troberti Mulsant (Coleoptera: Coccinellidae) were similarly reduced. Where ants were excluded experimentally by insectcide barriers, parasitism was 32%, compared to only 10% in the control, and predator densities were reduced three-fold. In a 24 h experiment, Pheidole megacephala was observed to remove about half the E. troberti larvae; Crematogaster sp. and Camponotus spp. were less efficient. The results show the locally strong interference of ants with biological control of the cassava mealybug. Despite this interference, mealybug populations in the rain forest were judged to be below damaging levels.
Expression of pyrethroid resistance in adult Helicoverpa armigera (Lepidoptera: Noctuidae) and selective mortality in field populations
Authors: Daly Joanne C. , Fisk Jennifer H.
Published: July 2009

Pyrethroid resistance was examined in adult Helicoverpa armigera (Hübner) in both laboratory and field selected strains. A series of F1 and backcrosses was made between a susceptible and an isofemale resistant strain. Dose-responses were obtained using contact with a treated surface inside a scintillation vial. Inheritance of resistance was consistent with an incompletely dominant major gene and resistance factors were greater than 100-fold. Piperonyl butoxide synergized the effects of the synthetic pyrethroid, fenvalerate, 1000-fold and eliminated resistance entirely. Field trials examined the mortality of resistant and susceptible adults exposed to commercial application rates of synthetic pyrethroids. Adults were immobilized and placed in cotton fields prior to aerial applications of insecticide. Survival of resistant adults was significantly greater than susceptible ones in both trials. It was concluded that selective mortality in the adult life-stage contributes to the evolution of pyrethroid resistance.
An optical method for automatic classification and recording of a suction trap catch
Authors: Hobbs S.E. , Hodges G.
Published: July 2009

A simple optical method for automatic recording and classification of a suction trap catch is described. The insects are illuminated against a dark background as they pass through a detection volume, and the amount of scattered light is used to measure insect size. The design centres on the detection volume, which is a volume through which the insects are made to pass, and within which they may be detected. The design is approached in four stages: 1. Delivery of insects to the detection volume. 2. Illumination of the detection volume. 3. Collection and detection of scattered light. 4. Signal analysis. The analysis could also be applied to related techniques. Results with a prototype demonstrate that classification into broad size categories is straight-forward (e.g. approximately three classes spanning body lengths of 2–7 mm), despite uncertainties of insect reflectivity, aspect and trajectory. Applications of the method are discussed, along with a brief mention of alternative techniques.
Effects of ivermectin treatment on the attraction of dung beetles (Coleoptera: Scarabaeidae and Hydrophilidae) to cow pats
Authors: Holter P. , Sommer C. , Grønvold J. , Madsen M.
Published: July 2009

The effect of ivermectin treatment of cattle on the rate of dung beetle colonization of cow pats was assessed by pitfall trapping in Denmark, Tanzania and Zimbabwe. Ivermectin was injected subcutaneously into heifers at the recommended dose of 0.2 mg/kg body weight, and dung to be used as bait in pitfalls was collected at intervals after treatment. In one experiment in Denmark, species of the scarab beetle Aphodius and the hydrophilids Sphaeridium and Cercyon, preferred control dung from untreated cattle; no preference was found in two other experiments, involving some of the same species. In the Tanzanian trials, the overall tendency for scarabaeid beetles was to prefer control dung. In Zimbabwe, two scarabaeid species (Euoniticellus intermedius (Reiche) and Liatongus militaris (Castelnau), both belonging to Oniticellini) were particularly attracted to dung from treated cattle; two other scarabaeids showed no preference. It is concluded: 1. That ivermectin therapy can affect the rate of dung colonization by attracting or repelling beetles. 2. That the responses are probably not caused by ivermectin per se, but by some side effect, the nature of which is obscure and unpredictable with our present knowledge.
A multiple basis for insecticide resistance in a strain ofCulex quinquefasciatus(Diptera: Culicidae) from Muheza, Tanzania, studied as resistance declined
Authors: Khayrandish A. , Wood R.J.
Published: July 2009

Evidence from observing resistance in decline in fourth instar larvae of the multiple resistant MUHEZA strain ofCulex quinquefasciatusSay from Tanzania (MUHEZA), showed that the major mechanisms for chlorpyrifos and propoxur resistance were different. Resistance to chlorpyrifos declined more than 400-fold (from an initial resistance ratio (RR) of 14285) while resistance to propoxur remained stable for at least 30 generations of laboratory culture. Significant synergism was found between propoxur and piperonyl butoxide (PB), propoxur and s,s,s-tributyl trithiophosphate (DEF), and permethrin and PB, but antagonism occurred between chlorpyrifos and PB, and no synergism between chlorpyrifos and DEF. Nine esterase isozymes active against naphthyl acetates on polyacrylamide gel electrophoresis (PAGE), were identified, four (A2, A3, B2, B3) showing polymorphism in activity, with very intense expression at one or other position in more than 32% of larvae, and null expression in less than 30%. The frequency of intense bands and of nulls both declined as resistance declined. A selected substrain (MUHEZA-fb), breeding true for A2, A3, B2 and B3 at the standard level of activity, showed almost stable chlorpyrifos resistance (RR=1428–1785) for approximately 35 generations. In mass larval assays ofin vitrosensitivity of acetylcholinesterase (AChE) to propoxur, the I50in MUHEZA was 950-fold greater than in a reverted resistant strain (RANGOON). Single larval assays indicated an AChE resistance allele (AceR) at frequency 0.43. PAGE of AChE revealed nine isozymes in MUHEZA and five in RANGOON, three of which were in common. It is concluded that propoxur resistance was due principally toAceRwith a minor influence from oxidases and non-specific esterases, while chlorpyrifos resistance was due to an interaction betweenAceRand non-specific esterases, the latter exerting the dominant effect.
An insect sorting device to be used in conjunction with insect suction samplers
Authors: Moore R. , Clarke R.T. , Creer S.
Published: July 2009

A new field-based method for sorting insects collected in suction samplers is proposed. Test sampling on grassland showed that for most taxonomic groups it was over 80% efficient. The efficiency of sorting for certain insect groups was influenced by the amount of debris in the sample. However, it was possible to determine a relationship between these two variables which enabled a correction factor to be calculated and used to compensate for this. It is suggested that popular use of this technique would radically increase the amount of research performed in the field.
Field and laboratory trials using a locally produced neem insecticide against the Sahelian grasshopper, Kraussaria angulifera (Orthoptera: Acrididae), on millet in Mali
Authors: Passerini J. , Hill S. B.
Published: July 2009

Field and laboratory trials were undertaken to determine effects and efficacy of neem extracts on the Sahelian grasshopper, Kraussaria angulifera (Krauss). Formulations of aqueous extracts were sprayed in field experiments. Concentrations of 0.5% and 1% were effective in reducing grasshopper feeding. Neem kernel powder applied systematically, partially protected millet against K. angulifera. The residual activity of the botanical insecticide was at least seven days. Analysis of plant selection behaviour showed that neem is primarily an antifeedant rather than a repellent for this insect. On first to third instar nymphs, growth regulating activity, expressed as difficulty in moulting or an incompleteness of sclerotization, may occur.
Characterization and inheritance of elevated esterases in organophosphorus and carbamate insecticide resistant Culex quinquefasciatus (Diptera: Culicidae) from Sri Lanka
Authors: Peiris H.T.R. , Hemingway J.
Published: July 2009

Culex quinquefasciatus Say from Peliyagoda, Sri Lanka, has elevated esterases A2 and B2. In vitro insecticide metabolism studies on the temephos-selected Sri Lankan Cutex quinquefasciatus strain, Pel RR, showed that fenitrothion was hydrolysed more rapidly than malathion. A significantly larger amount of fenitrothion was metabolized in Pel RR compared to the insecticide susceptible Pel SS strain, but the amount of malathion metabolized in the two strains was not significantly different. There was more esterase hydrolysis of fenitrothion than oxidase or glutathione S-transferase metabolism in Pel RR, which suggests that the elevated esterases in this strain have both metabolic and sequestering functions and that the relative importance of the two roles depends on the insecticide used. Genetic crosses of the temephos resistant and susceptible strains, showed that both resistance and elevated esterase activity were inherited as semi-dominant multi-genic characters. Hydrolysis of 2-naphthyl acetate was highest in the Pel RR strain, lowest in the Pel SS and intermediate in the F1 cross of the two strains. A minor maternal effect on resistance occurred with backcrosses involving resistant (F1) females, which gave consistently and significantly lower mortalities than those involving resistant (F1) males.
Comparison of permethrin treatments for bednets in The Gambia
Authors: Pleass R.J. , Armstrong J.R.M. , Curtis C.F. , Jawara M. , Lindsay S.W.
Published: July 2009

An experimental hut trial of bednets was undertaken in The Gambia to compare six different permethrin treatments, including a wash-resistant formulation, and to test the effect of thorough hand washing of the nets. The wash-resistant formulation on nylon and cotton nets deterred Anopheles gambiae Giles (sensu lato) from house entry. All treated bednets killed a significantly higher number of A. gambiae (sensu lato) than untreated nets. The ability to kill mosquitoes was not diminished with the wash-resistant and Wellcome formulations after washing unlike the normal ICI formulation, this result being consistent with the permethrin residues found by gas liquid chromatographic (GLC) analyses to persist on the nets after washing. The mortality on treated cotton nets was significantly less than on treated nylon nets. Of the unwashed nets only the cotton net was significantly repellent. Both washed and unwashed treated nets significantly reduced the proportion of human bloodfed mosquitoes that survived and were potentially able to transmit malaria. Although the wash-resistant formulation might prove more efficient at killing mosquitoes with time, as compared to the other treatments, in The Gambia, where women wash their nets frequently, we suggest that the cheapest and most readily available formulation is used on nylon nets where possible.
Host preference in African ticks (Acari: Ixodida): a quantitative data set
Authors: Cumming G.S.
Published: July 2009

Despite the large number of collection rocords available, there has recently been some debate concerning how host-specific ticks are. A quantitative data set is presented for the host preferences of African ticks. The results are based on 43,615 individual collection records from published sources covering most countries in mainland Africa. Out of 223 ticks species, 112 have been collected 20 times or more; 14 of these are generalists and at least 39 are potential specialists. Further collections are needed for greater clarity in many cases. It is important that people working on problems that relate to tick-host interactions are aware of the context in which these occur, lest they make false a prior hypotheses about the importance of hosts or parasites in the system.
Optimized simulation as an aid to modelling, with an application to the study of a population of tsetse flies, Glossina morsitans morsitans (Diptera: Glossinidae)
Authors: Hargrove J.W. , Williams B.G.
Published: July 2009

A method is described for optimizing models by linking simulation procedures with a non-linear regression programme. It is then possible to work towards a parsimonious model which contains those, and only those, variables required for an optimum fit. Using the observed values, and the predicted values from each simulation, the optimizing routine calculates the value of an appropriate loss function. It then makes small changes in the parameters governing the simulation, recalculates the predicted values and the first and second derivative of the loss function with respect to each parameter. The algorithm uses this information to minimize the loss function for a given formulation of the model. The model is improved by adding variables which can be shown statistically to improve the fit, and by removing those which do not. The use of the technique is illustrated with reference to a series of weekly estimates of the total numbers, births and survival probabilities of a population of male and female tsetse flies Glossina morsitans morsitans Westwood. Simulation involved following the lives of cohorts of flies, and of all their progeny, from the time they were deposited as larvae. Development and reproduction were regarded as fixed functions of temperature, but mortality rates of pupae and of adult flies depended on meteorological and biological variables, plus the level of trapping imposed on the population. Potential factors were added singly and the model thereby improved in an objective, stepwise manner. The best fit was achieved when effects on adult survival due to maximum temperature, various modes of trapping, and an annual cycle were included in the model. The optimized simulation technique has been used here in improving a model which describes a biological population but it could equally be used to improve models in any situation where data are fitted using simulation procedures.
Seasonally contrasting activity of African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae): implications for populations, pest status and management
Authors: Matthiesse J.N. , Learmonth S.E.
Published: July 2009

Flight and surface activity of the African black beetle, Heteronychus arator (Fabricius), detected by pitfall, light and window traps, was seasonally reversed. High surface activity relative to flight occurred in spring when beetles were mature, while relatively higher levels of flight occurred in autumn when they were immature. Pitfall trap captures were male-dominated in spring and female-dominated in autumn, and were a poor estimator of adult density. Light trap captures were consistently female-dominated. Although autumn flight was dispersive and inferred to have some role in population regulation, it was largely localized within the usual pasture habitat of the species. Some beetles flew into irrigated potato crops in autumn, but not specifically, as beetle abundance was consistently less than in surrounding dry pasture. High surface activity indicates spring is a strategic time for surface-applied control measures to prevent increase of H. arator in the next generation, a less disruptive alternative to conventional soil-incorporated insecticide directed at the new generation's larvae in summer. Such an approach would be best aimed early in the upsurge of activity, as most of the season's cohort of eggs was laid by the time surface activity peaked in mid-spring.
Selective host-feeding on parasitized hosts by the parasitoid Itoplectis naranyae (Hymenoptera: Ichneumonidae) and its implication for biological control
Authors: Ueno T.
Published: July 2009

Host-feeding by parasitoid wasps has been viewed as a positive attribute for biological control, because hosts are killed as a result of host-feeding in addition to parasitism. Host acceptance and host-feeding responses o unparasitized vs. conspecifically parasitized hosts by the parasitoid wasp Itoplectis naranyae Ashmead were studied in the laboratory. Female I. naranyae selected to oviposit in unparasitized hosts and those that had been parasitized I h previously, in equal proportions, even when allowed access to both types of host. Females also fed upon both types of host equally. Females, however, avoided ovipositing in hosts parasitized 40 h and 70 h previously, and preferentially fed upon them when allowed access both to parasitized and to unparasitized hosts. Parasitoid progeny in hosts which had been used for host-feeding suffered a high degree of mortality. Females used host internal changes as cues for deciding whether to feed on hosts. It is suggested that immature parasitoid mortality can be increased due to female preference for using parasitized hosts for host-feeding. Hence, host-feeding by I. naranyae may not be an advantageous biological control characteristic. The adaptive significance of selective host-feeding is also discussed.
Ants in tropical irrigated rice: distribution and abundance, especially of Solenopsis geminata (Hymenoptera: Formicidae)
Authors: Way M.J. , Islam Z. , Heong K.L. , Joshi R.C.
Published: July 2009

At least 62 species of ants were caught at baits in Philippine rice fields, notably in the bunds (levées) of irrigated rice. Many were relatively uncommon or localized. Apart from the ubiquitous Tapinoma sp. nr indicum Forel the most widespread was the aggressive Solenopsis geminata (Fabricius) which was often very abundant in fields with bunds that were disturbed by regular repair. This ant was scarce or absent in relatively undisturbed well-vegetated bunds where Pheidole spp. were sometimes common and where up to 14 different species were recorded in bunds of a single field. Colonies were spaced out along the bunds where foraging territories sometimes overlapped, except for those of the competing dominants S. geminata and Pheidole spp. In general, S. geminata retained its overall foraging areas from year to year but those of non-dominant ant species could vary considerably. Bunds of low-lying fields that are deeply flooded in the wet season were recolonized by S. geminata in the wet season. This ant occurred as separate colonies with workers from nests that differed in degree of mutual aggression. Such aggression was not observed in foraging areas. Solenopsis geminata and other species foraged into, and nested within, dry fallowed fields after the crop was harvested. In the crop season, they foraged across mud during periods of up to one week when farmers allow irrigated rice fields to drain before flooding. Solenopsis geminata workers also foraged across the closed crop canopy. At such times they were commonly observed preying on hemipteran and lepidopteran pests and on eggs and young golden snails (Pomacea canaliculata Lamarck) which are serious rice pests in the Philippines.
Variation in the photoperiodic response within natural populations ofMyzus persicae(Sulz.)
Authors: Blackman R. L.
Published: July 2009

In laboratory experiments, the responses to short photoperiod (10 h) of clones ofMyzus persicae(Sulz.) established from random samples of summer populations in southern England were generally stable and characteristic for each clone, and were of four distinct categories: (i) holocyclic, with clones terminated under short photoperiod by production of male and female sexual forms, (ii) intermediate, with a mixed response involving alatae intermediate between gynoparae and virginoparae, (iii) androcyclic, with production of some males along with continued parthenogenesis, and (iv) truly anholocyclic, with no significant response to short photoperiod. All four types can occur within one population, but holocyclic and androcyclic forms are most common. There were clear differences in the proportions of these forms occurring simultaneously on adjacent crops of different host-plants, and in different years on the same crop in the same field. Males of androcyclic clones were able to transmit their partially anholocyclic character through the sexual phase.
Relationship of the movements of aphids over the host-plant to their spatial distribution
Authors: Lowe H. J. B.
Published: July 2009

In both experimental and naturally developed colonies,Aphis fabaeScop., andAcyrthosiphon pisum(Harris) were concentrated on the upper parts of broad bean plants.A. pisumresembled Myzus persicae (Sulz.) rather thanAphis fabaeby normally infesting leaves, not stems. Colonies ofM. persicaewere dispersed over the whole plant. In laboratory experiments, apterous adult aphids were observed walking on bean plants, and their activity was recorded in terms of their actions at each node. Moving aphids of both species tended to maintain their direction at a node although the structure of the plant does not appear to favour this. Aphids of both species changed their direction of movement more often after going onto the leaf at a node than when they stayed on the stem.M. persicaeadults went upwards as often as they went down, but those ofAcyrthosiphon pisumwalked up more often than down and were more likely to turn round if they were moving downwards. These differences in the behaviour of active individuals would tend to produce the differences between the observed spatial distributions of the two species, although other factors, including leaf age and reproductive rates are probably more important in determining the form of aphid colonies.
Protein-feeding by the males of the Australian bushfly Musca vetustissima Wlk. in relation to mating performance
Authors: Tyndale-Biscoe Marina
Published: July 2009

Male bushflies (Musca vetustissima Wlk.) are attracted to and feed on proteincontaining substances, although under laboratory conditions they ingested smaller quantities of blood and dung than did the females. Laboratory experiments showed that they are able to obtain water from fresh dung and blood, but no physiological requirement for the protein was found. Feeding on protein did not increase the life span or the total numbers of matings; it did not improve the mating success of males that had previously been multiple-mated; and it did not enhance sexual activity, contrary to the situation found in Lucilia cuprina (Wied.). It is concluded that protein feeding in male bushflies is casual, possibly a behaviour pattern that ensures their presence near females.
Assessment of methoxy-DDT as a residual spray against mosquitoes in verandahtrap huts at Magugu, Tanzania
Authors: Hudson J. E.
Published: July 2009

The effects of residual sprays of methoxy-DDT wettable powder at 2 g/m2 on the mortality and behaviour of Anopheles gambiae Giles, Mansonia uniformis (Theo.) and Culex pipiens fatigans Wied. females were investigated in four verandah-trap huts, one of which was used as control. The overall mortality of no species ever exceeded 29%, and no consistent deterrent effect on entry was demonstrated. The proportions of mosquitoes in the exit traps were, for A. gambiae 80–90% in treated huts and 29–70% in the control, for M. uniformis 90–100% in treated and control huts, and for C. p. fatigans 26–84% in treated huts and 38–66% in the control. There were more unfed mosquitoes of all three species in the treated huts than in the control, for A. gambiae 35–64% and 10–53%, respectively, for M. uniformis 38–84% and 35–64%, respectively, and for C. p. fatigans 22–58% and 21–43%, respectively. Bioassays with wild-caught A. gambiae exposed to the treated surfaces for one hour, showed that the deposits remained highly toxic for 16 weeks on grass, six weeks on iron and two weeks, or less, on mud.
Flight periodicities and vertical distribution of Aedes cantons (Mg.), Ae. geniculatus (Ol.), Anopheles plumbeus Steph. and Culex pipiens L. (Dipt., Culicidae) in southern England
Authors: Service M. W.
Published: July 2009

After preliminary collections with suction traps at heights of 30 and 135 cm had shown that most mosquitoes were caught in the lower trap, suction trap catches were made for three years from about April to November in a wooded area in southern England. Flight periodicities of females of Aedes cantans (Mg.) and Ae. geniculatus (Ol.) and of both sexes of Anopheles plumbeus Steph. and Culex pipiens L. were determined by traps incorporating automatic segregating devices. In all species maximum flight activity was between 19.00–20.00 h GMT. The biting cycles of the first three species were similar to their general flight patterns. Mean hourly densities of all four species were calculated from the suction trap catches. Collections were made with traps placed at five different heights (23–223 cm) in 1968 and at eight heights (23–550 cm) in 1969 and 1970. In most species there was a well defined and rapid decline in aerial density of both sexes with increasing height, but more unfed females and males of Culex pipiens L. and females of Culiseta morsitans (Theo.) were caught in the highest trap. From about mid-August onwards, when adults of Culex pipiens were searching for hibernation sites, both males and females with fat reserves were commonest in the lowest trap. The slopes of the regression lines of log. density on log. height were calculated separately for Ae. cantans and C. pipiens, and for all adults combined for five less common species. In all catches, except those of C. pipiens, unfed females predominated.
Use of a multi-component pheromone formulation for control of cotton bollworms (Lepidoptera: Gelechiidae and Noctuidae) in Pakistan
Authors: Chamberlain D.J. , Critchley B.R. , Campion D.G. , Attique M.R. , Rafique M. , Arif M.I.
Published: July 2009

A hand-applied ‘twist-ti’ pheromone formulation containing the combined pheromones of Pectinophora gossypiella (Saunders) (Gelechiidae), Earias vittella (Fabricius) and E. insulana (Boisduval) (Noctuidae) was used in trials conducted in Pakistan from 1986 to 1988. In plots of cotton ranging in area from 2.8 to 6.0 ha, season-long control of the bollworm complex was achieved using the pheromone formulation applied alone or together with one conventional insecticide treatment, with the conventional insecticide spray programme requring up to five applications of insecticide to achieve a similar level of control. No significant differences were found in yield estimates from plots treated with pheromones compared with plots receiving conventional insecticide treatments. Significantly higher levels of boll infestation and lower yield estimates occurred in control plots where neither pheromones nor insecticides were applied.
Morphology, distribution, and the role of trichomes in cowpea (Vigna unguiculata) resistance to the legume pod borer, Maruca testulalis (Lepidoptera: Pyralidae)
Authors: Oghiakhe S. , Jackai L.E.N. , Makanjuola W.A. , Hodgson C.J.
Published: July 2009

Studies on the morphology and distribution, and the role of trichomes in damage to cowpea (Vigna unguiculata) by the legume pod borer Maruca testulalis (Geyer) showed that trichome cover on individual cultivars varied in trichome length and density, but not in trichome type from different plant parts. Trichome density on different parts decreased with increasing plant age. Significant (P <0.05) negative correlations were obtained between total trichome density on pods, pod infestation and damage severity. In contrast, correlations between length of non-glandular trichomes on pods, pod infestation and damage severity were not significant. Results suggest that trichome length may be less important than density in reducing pod damage by M. testulalis in cultivated cowpeas. It is, therefore, concluded that breeding for a higher level of trichomes in high yielding and agronomically desirable cowpea cultivars, will serve as an important component in the integrated management of M. testulalis.
Flight behaviour of tsetse flies in thick bush (Glossina pallidipes (Diptera: Glossinidae))
Authors: Paynter Quentin , Brady John
Published: July 2009

An odour-baited electric net placed in thick bush caught more Glossina pallidipes Austen when sited at ground level (0.2–1.2 m) than when sited in the top of the bush (1.4–2.4 m) or just above it (2.6–3.6 m). However, a similar net running concurrently 4 m away in a game trail through the bush caught far more flies. When electric nets were placed in the centre of two adjacent game trails in this bush and then one of the trails was barricaded with branches from nearby bushes, the catch declined in that trail and increased proportionately in the other. It is inferred that tsetse flies navigate up host odour plumes by finding gaps in thick vegetation rather than by flying over the top or through it, and that game trails are important forms of such gaps. The implications for siting traps and targets are noted.
Notes on the habits of Glossina morsitans in Nyasaland and the adjoining Territories
Authors: Sharpe Alfred
Published: July 2009

Throughout the Nyasaland Protectorate there are many areas which are infested by Glossina morsitans; and this species is also to be found in North Eastern Rhodesia, and in German and Portuguese territory bordering on Lake Nyasa. I have been frequently through all these territories during the last 22 years, and know them well.
The bionomics of Glossina; a review with hypothetical conclusions
Authors: Fiske William F.
Published: July 2009

There are certain frequently observed and rather mysterious phenomena associated with the bionomics of the better known species of Glossina; such, for example, as the local disparity between the sexes and the apparently arbitrary distribution of the fly. It is difficult, if not impossible, to explain these, or at least no explanation has yet been put forward which is wholly in agreement with all that has been recorded of the subject. It appears necessary in consequence to consider some part of the generally accepted bionomic history of these liies as being based on insufficient evidence.
The Myzorhynchus group of Anopheline mosquitos in Malaya
Authors: Strickland C.
Published: July 2009

The following is a summary of the conclusions arrived at in the foregoing paper:—

(1) the species sinensis, barbirostris, umbrosus, albotaeniatus and asiatica have been considered valid;

(2) the species vanus, annularis, minutus, paeditaeniatus and separatus have been rejected as invalid;

(3) certain new characters of the valid species have been noticed;

(4) the descriptions of the species have been revised;

(5) the genus Patagiamyia has been rejected, as also the genus Lophoscelomyia, both having been included in the genus Myzorhynchus;

(6) it is suggested that the Myzorhynchus group forms a series sufficiently distinct from other Anophelines to make it advisable to give it a separate generic title.
A proposed method of controlling the ravages of leaf-eating caterpillars
Authors: Dudgeon Gerald C.
Published: July 2009

The subject which I propose to introduce is one which is of such very great importance in agricultural practice in different parts of the world that I trust it may not be out of place to give a brief account of the experiments in connexion with it, which we have been conducting in Egypt and which, although still incomplete, indicate very favourable results.
On the Oriental Culicid genus Leicesteria, Theobald
Authors: Edwards F. W.
Published: July 2009

The genus Leicesteria was founded by Theobald in 1904 (Entomologist, xxxvii, p. 211) for a species of mosquito found by Dr. G. F. Leicester in the Malay States, the most remarkable character of which was the great length of the female palpi, a condition known otherwise among the Culicidae only in Anopheles, Megarhinus and Mucidus, all genera to which the new species was obviously unrelated. Subsequently Dr. Leicester* placed on record his discovery of four other species essentially similar to Theobald's Leicesteria longipalpis; for one of these he created the new genus Chaetomyia. Additional species referable to the genus have since been described by Theobald.†
The Yellow-headed Coffee Borer (Dirphya (Nitocris) Princeps, Jord.)
Authors: Gowdey C. C.
Published: July 2009

The first time that this beetle proved itself to be a pest of coffee to any great extent in this country was on native coffee, Coffea robusta, in the Chagwe District, in 1910, at which time I began to investigate it. Since the first outbreak it has been found attacking C. arabica on several estates. Some of the estates have suffered serious damage, especially the older ones which are badly affected by the coffee leaf-disease, Hemeleia vastatrix. With a single exception, I have been able to trace the origin of the outbreak to plots in which leafdisease was already present and in which, consequently, the trees were the least vigorous.
Notes on Scale-Insects (Coccidae).—Part II
Authors: Newstead R.
Published: July 2009

This paper deals with a number of Coccids which have been forwarded through the Imperial Bureau of Entomology from the following countries: The Dutch West Indies, Barbados, British Guiana, Zanzibar, Uganda, Nyasaland, and Nigeria. Five species are herein described as new to science, the others, for the most part, are Avell-known pests affecting cultivated plants in various parts of the world.
African Aphididae
Authors: Theobald Fred. V.
Published: July 2009

Our knowledge of the Aphididae of Africa is as yet very limited, this important group of insects having been but little studied, except in Europe and North America. At present only thirty-five species are recorded for the whole African continent, about the number one can collect in a single afternoon in one's own garden in England. It will be noticed that several common European species are recorded, and that they are as destructive in Africa as in Europe, such as the Common Cabbage Aphis (A. brassicae) and the Ribes and Lettuce Aphis (Rhopalosiphum lactucae). Several others occur which have a world-wide distribution, such as the Black Peach Aphis (Aphis persicae), and the Woolly Aphis (Eriosoma lanigerum), doubtless having been distributed on nursery stock, the former as ova and the latter as adults. Fuller has reported destroying and fumigating strawberry plants attacked by Aphis sent from Europe, and Lounsbury records the presence of Apple Aphis eggs on imported stock. Undoubtedly these insects are constantly being distributed from country to country with imported plants, trees and shrubs.
The Tropical Bed-Bug, Clinocoris hemiptera, Fabr
Authors: Rothschild N. Charles
Published: July 2009

Dr. Horvath has recorded the fact that the bed-bug described under the various names, hemiptera, rotundata, macrocephala and horrifer, are all the same species, and that this insect must be termed hemiptera, as that is the oldest name. The insect iu question is widely distributed over the tropics of both the Old and New World. The type specimen is still preserved in the Copenhagen Museum, and through the kindness of the authorities there I have recently been able to examine it, and can confirm Dr. Horvath's views. The type example of Clinocoris foedus, Stal, which was described from an example taken in Columbia, is in the Stockholm Museum, and was also submitted to me. This insect differs from hemiptera by having the lateral margin of the pronotum slightly but distinctly explanate and curved upwards. Whether this character is due to the shrinkage of the example, or whether it is really there, it is impossible to tell. In any case, should foedus, Stal, utimately prove to be the same as hemiptera, the name would simply form one more synonym of this species, though in all probability, when more material is discovered, foedus will be shown to be a distinct species.
Second report on Glossina investigations in Nyasaland
Authors: Lamborn W. A.
Published: July 2009

Until 13th March I remained in the Proclaimed Area, then, as the weather condition were very bad, and as moreover the grass had so overgrown all the paths, which are little used, that my movements were very much hampered, I removed to Fort Johnston at the southern extremity of the Lake, and have since been working in its neighbourhood.
A new Thrips damaging coffee in British East Africa
Authors: Williams C. B.
Published: July 2009

The Thrips described below was submitted to me by Mr. Guy A. K. Marshall, Director of the Imperial Bureau of Entomology, to whom it had been sent by Mr. T. J. Anderson, the Government Entomologist in British East Africa.
Some new neotropical Simuliidae
Authors: Knab Frederick
Published: July 2009

Dr. Andrew Balfour, Director of the Wellcome Bureau of Scientific Research, has submitted to the writer for study part of the Diptera collected on his recent voyage in the American tropics. A species of Simulium from the valley of the Atrato River in Colombia proves to be new and is described below. Through the good offices of Dr. Balfour further interesting material was received from K. S. Wise, Surgeon-General for British Guiana, and from F. W. Urich, Entomologist of Trinidad. These lots contained an additional new species of Simulium each, of which the descriptions follow. Diptera belonging to other groups and of economic interest will be treated in subsequent papers.
Quelques observations préliminaires sur les moeurs de la Glossina brevipalpis
Authors: le Dccteur Schwetz Par
Published: July 2009

La Glossina brevipalpis est certainement l'espèce de glossine la plus répandue, dans certaines régions du moins, après la G. morsitans et la G. palpalis, mais elle a des moeurs si particulières que, sans les connaître, on ne peut découvrir son existence que par un simple hasard. En effet, les moeurs de la G. brevipalpis sont vespérales et, en partie, matinales, après le lever et surtout avant et après le coucher du soleil. Durant le reste de la journée la mouche est complétement inactive et se tient cachée (dans les herbes?).
Ooencyrtus pacificus, a new egg parasite from Fiji (Hym.)
Authors: Waterston James
Published: July 2009

♀.—Head and body shining black, with slight metallic reflections as follows:—Genae dark green, purplish and carmine towards the eye; upper surface of abdomen, in some lights, very faint dark green; tegulae like the rest of the thorax. Antennae dark brown, almost black on scape, pedicel and base of funicle; last two funicular joints lighter; club entirely pale. Wings almost hyaline, but with a faint tinge of yellow, and slightly browned on the submarginal towards the costa, as well as on the punctiform marginal vein. Legs entirely pale yellowish; the posterior femora a little browner on the dorsal edge towards the apex.