The egg, larval, pupal and adult abundance of the clover root weevil Sitona lepidus Gyllenhal (Coleoptera: Curculionidae) was monitored at three sites for the first ten years following the discovery of this exotic pest in the Waikato region of New Zealand. The species went through an initial boom and bust cycle at two sites, with populations reaching up to 1800 larvae m−2. Thereafter, winter larval populations were relatively stable, ranging between 450–750 m−2. Unlike in the Northern Hemisphere, S. lepidus was found to have two generations a year in the Waikato region of New Zealand. Pasture white clover content at the time of peak adult numbers was positively related to the subsequent peak larval populations for each generation. The factors contributing to the emergence of S. lepidus as one of the most important pasture pests in New Zealand are discussed.

Males of Glossina morsitans Westw. and G. pallidipes Aust. labelled with radiocaesium (137Cs) were released in their natural habitat and later recovered on four occasions in the hot, hot wet and cold dry seasons in Rhodesia. The rate of excretion of the radioisotope was related to previous laboratory results to give estimates of activity, temperature regulation and energy utilisation in the field. It is considered that male G. morsitans are unlikely to fly for more than a few minutes per day. The hunger cycle duration is estimated as 3·5–4 days for G. morsitans males and 5·5 days for G. pallidipes males. Temperature regulation within the range 23–27°C was exhibited by both species, especially in the winter.

Gene flow between field populations of the cereal aphids Sitobion avenae (Fabricius), Sitobion fragariae (Walker) and Rhopalosiphum padi (Linnaeus) is examined using statistical analyses of allozyme frequency data (both Slatkin's and F statistics). Analysis using Slatkin's method confirms the conclusions previously drawn from earlier analyses. Thus there is found to be high gene flow between subpopulations of S. avenae and R. padi, and a more restricted level between local S. fragariae subpopulations, especially when infesting the secondary host (cocksfoot grass, Dactylis glomerata). The value of Nm (number of immigrants per generation) calculated for S. avenae was approximately 2 and is indicative of high gene flow i.e. Nm>1.0. Also, as previously found by x2 genetic contingency testing, the F statistical analysis confirms that S. fragariae subpopulations infesting D. glomerata are genetically more heterogeneous than those infesting the primary host, blackberry, Rubus fruticosus agg. Hence, there may be less gene flow between populations on the secondary host compared with that on the primary. The results obtained are compared with the flight behaviour of these particular aphid species and to their respective host plant abundances. The advantages and disadvantages of both Slatkin's method and F statistics for analysing insect population genetic structure are noted.

Although it may be convenient to distinguish them, hibernation, aestivation, and diapause are in reality different manifestations of the same phenomenon which we may call diapause. The symptoms of this condition are a marked depression of metabolism and quiescence; and the remote causes as suggested by observation are cold, heat, drought and (or) certain nutritional peculiarities such as richness or dryness of food. These factors may act singly or in combination, with different factors dominant in different cases.

Helicoverpa spp. and mirids, Creontiades spp., have been difficult to control biologically in cotton due to their unpredictable temporal abundance combined with a cropping environment often made hostile by frequent usage of broad spectrum insecticides. To address this problem, a range of new generation insecticides registered for use in cotton were tested for compatibility with the assassin bug, Pristhesancus plagipennis (Walker), a potential biological control agent for Helicoverpa spp. and Creontiades spp. Indoxacarb, pyriproxifen, buprofezin, spinosad and fipronil were found to be of low to moderate toxicity on P. plagipennis whilst emamectin benzoate, abamectin, diafenthiuron, imidacloprid and omethaote were moderate to highly toxic. Inundative releases of P. plagipennis integrated with insecticides identified as being of low toxicity were then tested and compared with treatments of P. plagipennis and the compatible insecticides used alone, conventionally sprayed usage practice and an untreated control during two field experiments in cotton. The biological control provided by P. plagipennis nymphs when combined with compatible insecticides provided significant (P<0.001) reductions in Helicoverpa and Creontiades spp. on cotton and provided equivalent yields to conventionally sprayed cotton with half of the synthetic insecticide input. Despite this, the utilization of P. plagipennis in cotton as part of an integrated pest management programme remains unlikely due to high inundative release costs relative to other control technologies such as insecticides and transgenic (Bt) cotton varieties.

Glasshouse and field screening showed that several varieties of cowpea (Vigna unguiculata) in the germplasm collection at the International Institute of Tropical Agriculture at Ibadan, Nigeria, had promising levels of resistance to damage by larvae of Cydia ptychora (Meyr.). There was no preference between varieties for oviposition in the glasshouse, but varietal differences in damage to pods and seeds occurred due to differences in the pod-boring and seed-feeding success of larvae. Large numbers of seeds per pod in some varieties diluted the effects of a given larval density and resulted in low percentages of damaged seed. A measure of relative susceptibility was devised that overcame the problem of chance escape from attack by certain pods. Resistance in glasshouse screening was not necessarily related to resistance in the field, where plant growth habits and the ecological requirements of the adult moths are more fully expressed and play an important role in determining the outcome of the plant-insect interaction. The most resistant variety in the glasshouse, Vita-3, was least resistant in the field, partly because it was partially photosensitive and produced few flowers and pods in the early growing season in Ibadan. Two varieties, TVu 946 and TVu 2994, may have escaped severe attack by maturing quickly. The former is small-leaved, non-vigorous, carries its pods on long peduncles well above the foliage and consequently constitutes an unsuitable habitat for daytime sheltering by adults. It was the least damaged variety in the field trial. The latter was most attacked by other pod-feeding pests, and the consequent reduction in seed weight and quality appeared to enhance the level of damage caused by C. ptychora.

The interesting moth described below was bred from larvae which were causing serious damage to pine trees in Cyprus, by the Entomologist to the Department of Agriculture in Cyprus, Mr. D. S. Wilkinson, who has presented to the British Museum (Natural History), through the Imperial Bureau of Entomology, the two males which he bred.

The aim of this study was to investigate the foraging behavior of Aphidius matricariae (Haliday) (Hymenoptera: Braconidae) as a biological control agent of Myzus persicae nicotianae Blackman (Hemiptera: Aphididae), a key and cosmopolitan pest of tobacco fields. To achieve a strategy for the control of this pest and a mass-rearing program of the parasitoid, host stage preference, switching, functional response, and mutual interference of A. matricariae were investigated at 25 ± 1°C, 70 ± 5% RH and 16:8 h L:D photoperiod. The parasitoid showed a preference for third- and fourth-instar nymphs of tobacco aphid in both choice and no-choice experiments. Using the Murdach's model, switching behavior was observed in A. matricariae between different density proportions of third- and fourth-instar nymphs. Further, the parasitoid exhibited a type II functional response when it was offered to third-instar nymphs of M. persicae nicotianae at six densities (2, 4, 8, 16, 32, and 64). Based on the linear regression analysis, there was a significance difference between the logarithm of per capita searching efficiency and the logarithm of parasitoid density. As the wasp density increased, per capita searching efficiency decreased. The result of this study revealed that A. matricariae is an effective agent in the integrated management of M. persicae nicotianae. In addition, application of these results can be important in mass-rearing program of A. matricariae.

The codling moth Cydia pomonella is a major pest of global significance impacting pome fruits and walnuts. It threatens the apple industry in the Loess Plateau and Bohai Bay in China. Sterile insect technique (SIT) could overcome the limitations set by environmentally compatible area-wide integrated pest management (AW-IPM) approaches such as mating disruption and attract-kill that are difficult to suppress in a high-density pest population, as well as the development of insecticide resistance. In this study, we investigated the effects of X-ray irradiation (183, 366, 549 Gy) on the fecundity and fertility of a laboratory strain of C. pomonella, using a newly developed irradiator, to evaluate the possibility of X-rays as a replacement for Cobalt60 (60Co-γ) and the expanded future role of this approach in codling moth control. Results show that the 8th-day is the optimal age for irradiation of male pupae. The fecundity decreased significantly as the dosage of radiation increased. The mating ratio and mating number were not influenced. However, treated females were sub-sterile at a radiation dose of 183 Gy (20.93%), and were almost 100% sterile at a radiation dose of 366 Gy or higher. Although exposure to a radiation dose of 366 Gy resulted in a significant reduction in the mating competitiveness of male moths, our radiation biology results suggest that this new generation of X-ray irradiator has potential applications in SIT programs for future codling moth control.

Predicting potential pollination services of wild bees in crops requires knowledge of their spatial distribution within fields. Field margins can serve as nesting and foraging habitats for wild bees and can be a source of pollinators. Regional differences in pollinator community composition may affect this spill-over of bees. We studied how regional and local differences affect the spatial distribution of wild bee species richness, activity-density and body size in crop fields. We sampled bees both from the field centre and at two different types of semi-natural field margins, grass strips and hedges, in 12 strawberry fields. The fields were distributed over four regions in Northern Europe, representing an almost 1100 km long north-south gradient. Even over this gradient, daytime temperatures during sampling did not differ significantly between regions and did therefore probably not impact bee activity. Bee species richness was higher in field margins compared with field centres independent of field size. However, there was no difference between centre and margin in body-size or activity-density. In contrast, bee activity-density increased towards the southern regions, whereas the mean body size increased towards the north. In conclusion, our study revealed a general pattern across European regions of bee diversity, but not activity-density, declining towards the field interior which suggests that the benefits of functional diversity of pollinators may be difficult to achieve through spill-over effects from margins to crop. We also identified dissimilar regional patterns in bee diversity and activity-density, which should be taken into account in conservation management.

The seed fly Mesoclanis polana (Diptera: Tephritidae) was released in Australia in 1996. Its impact on seed production of bitou bush (Chrysanthemoides monilifera subsp. rotundata) was monitored at eight sites along the New South Wales coast from 1996 to 2004. Peak flowerhead production occurred in autumn (March to May); therefore, samples collected in May of each year were used to compare abundance and impact of M. polana across sites and between years. Latitude had a significant effect on abundance and impact of M. polana. By May 2004, 99.6% of flowerheads at the five most northern sites contained at least one egg, while 64% of flowerheads from the two most southern sites contained at least one egg. In May 2004, mean numbers of M. polana eggs per flowerhead were between 13 and 17 at four of the six northern sites and below two at the two southern sites. In May 2004, average seed destruction by M. polana was 58% at the four most northern sites and 11% at the two most southern sites. The highest level of seed destruction recorded was 86% at Kingscliff in May 2003. Percentage seed destruction in May provided a reasonable estimate of seed destruction for the whole year. Parasitoids were found throughout the range of M. polana in Australia. Their attack rate on M. polana was less than 10% at all sites, except at the two most northern sites where parasitism of up to 27% was recorded. Parasitism results are compared with predictions made following an earlier study. The release of Mesoclanis magnipalpis, a species suited to cooler environments, is recommended for the southern range of C. monilifera subsp. rotundata.

Individual wild-caught sandflies from Iran were examined for infections of Wolbachia pipientis by targeting the major surface protein gene wsp of this intracellular α-proteobacterium. In total, 638 male and female sandflies were screened, of which 241 were found to be positive for one of three wsp haplotypes. Regardless of geographical origins and habitats, Phlebotomus (Phlebotomus) papatasi and other sandfly species were found to be infected with one common, widespread strain of A-group W. pipientis (Turk 54, GenBank accession EU780683; AY288297). In addition, a new A-group haplotype (Turk07, GenBank accession KC576916) was isolated from Phlebotomus (Paraphlebotomus) mongolensis and Phlebotomus (Pa.) caucasicus, and a new B-group haplotype (AZ2331, GenBank accession JX488735) was isolated from Phlebotomus (Larroussius) perfiliewi. Therefore, Wolbachia was found to occur in at least three of the incriminated vectors of zoonotic cutaneous leishmaniasis and zoonotic visceral leishmaniasis in different geographical regions of Iran. It may provide a new tool for the future control of leishmaniasis.

Ticks were collected from 2136 small mammals, comprising 5 bats (5 species), 14 elephant shrews (3 species), 84 Crocidura shrews (5 species), 25 hares (1 species), 10 small carnivores (3 species), 3 hyraxes (1 species) 1998 rodents (33 species), and from 41 birds (19 species) at various localities in Zambia. From these hosts 6568 ticks (4384 larvae, 1686 nymphs, 317 males and 181 females) were recovered. Twenty-three species were positively identified and nineteen other species were assigned to genus or species-group. Host and tick records are tabulated by regions collected and for each of the two regions with the largest collections, the records are tabulated by months. The ticks collected in the high montane area near the Malawi border differed significantly from collections in other areas studied, reflecting host and climate differences. In the two areas tabulated by month, most of the immature ticks were recovered in the cool dry winter months (April to August).

The influence of the host plant of the cassava mealybug, Phenacoccus manihoti Matile Ferrero on the encyrtid parasitoid Apoanagyrus lopezi De Santis was studied in the laboratory. Four different host plants were used: two cultivars of cassava, Manihot esculenta (Euphorbiaceae), cv. Incoza and cv. MM79; Faux caoutchouc, a hybrid of M. esculenta × M glaziovii; and talinum Talinum triangularae (Portulacaceae), a common weed in cassava fields. Plants were selected for different levels of antibiotic resistance to P. manihoti. Mealybug mortality due to host feeding by the adult parasitoid and the percentage of mealybugs parasitized were significantly lower when mealybugs were reared on the Manihot cultivars and hybrid than when reared on talinum. However, the encapsulation rate was significantly lower in P. manihoti reared on talinum. The highest percentage parasitism and the lowest rate of emergence were recorded on cv. Incoza, the most resistant Manihot cultivar. The sex ratio did not vary significantly with the host plant used. The total developmental time and size of male and female progeny of A. lopezi differed significantly between P. manihoti reared on different host plants. Among Manihot plants, parasitoid size was positively correlated with development time and negatively with plant resistance. Results suggest that the parasitoid, A. lopezi, might perform better if cassava cultivars were selected for their strong antixenosis but low antibiotic characteristics.

The planting of cocoa in Malaya at the present time must be considered to have reached the experimental stage only, and the data obtained so far are insufficient to warrant a recommendation for its adoption either as a plantation or a small-holder's crop.

1. Aphidius granarius is an internal parasite of Myzus kaltenbachi, where the latter is found infesting corn crops in South Wales.

2. The emergence of the adult parasite is described. Mating takes place within two hours of emergence, the females may be mated with more than one male.

3. A brief description of the morphology of the egg, larval, prepupal and pupal stages is given.

4. The rate of reproduction of the females of A. granarius is high, with female: male as 12·9: 10. Unmated females always produce males.

5. The adult parasite under normal conditions lives for 21–27 days and flies readily under favourable meteorological conditions. Within limited areas dissemination may be brought about most effectively by mature parasitised apterae.

6. The factors limiting the effectiveness of the parasite are briefly described. The degree of control at the end of May in the field may approximate to 90 per cent.

After exposure of nymphs of some Pyrrhocorid bugs to contact with certain papers or wood chips, abnormal adults are produced. Some have crumpled wings (distorted adults) and a proportion of these do not berrd, others have wing buds resembling those of a last-stage nymph and can never breed (juvenile adults). A study was made on Pyrrhocoris apterus L. and Dysdercus intermedius Dist. of the source of the factors causing these abnormalities, which were more severe in the latter species.

Exposure of nymphs to paper fro the Scientific American or the Sunday Express resulted in the production of 60–100 per cent. ‘juvenile’ adults, the others showing lesser deformities. Chips from the Baisam Fir (Abies balsamea) resulted in almost 100 per cent. ‘juvenile adults’ in Dysdercus and over 80 per cent. distorted adults in yPyrrhocoris. Chips from two other common American pulp trees (Pseudotsuga taxifolia and Tsuga albertiana) resulted in only a few distorted adults and no ‘juvenile adults’. Several chemial pulps were tested but none caused deformities, and it was conculded that the chemical processes removed all the active priniciples, even from the wood of the Balsam Fir. Mechanically produced pulp from the Balsam Fir was, in contrast, fully active. It was conculded that daily newspapers may contain enough mechanical pulp from active woods to produce the deformities, but that the active material must be in substances added later in manufacture to the papers used in the Scientific American, some copies of Nature, and tissues.

A number of tree products (mainly terpenoids) that are commonly added to paper in the final stages of manufacture were tested as extracts applied to filter paper. Tall oil rosin had little or on effect on the growth of either species, but it resulted in an increase in the number of eggs laid. Gum rosin had little effect on either species, except to produce a few distorted adults. Wood rosin likewise had little effect on P. apterus, but produced many distorted adults of D. intermedius, of which very few laid eggs. Bornly acetate, a common component of the tree orsins, produced some distorted adults of both species, and greatly reduced fertility in D. intermedius.

None of the qctive mqteriqls affected locusts (Schistocera gregaria Forsk. and Locusta migratoria migratorioides R. & F.) except that myrrh oil (a terpenoid) increased the rate of sexusl maturation.

Two small-scale experiments were carried out to test the effectiveness of narrow target barriers against re-invasion by Glossina pallidipes Austen and G. m. morsitans Westwood. The barriers consisted of either one or two lines of targets, with the targets placed at distances of c. 16 m apart within the lines. At this spacing the targets are so close together that a fly could scarcely fail to see at least one target as it crossed the barrier. Nonetheless, in both cases, flies penetrated the barriers with probability c. 10% as judged by catches in odour-baited traps on either side of the barrier. Narrow barriers, even at very high target density, are ineffective against tsetse invasion. This accords with previous theoretical predictions and mark-recapture studies, and suggests that wider barriers are needed for the prevention of re-invasion of cleared areas by tsetse.

Smallholder crops (sunflower, maize, sorghum and cotton) were grown in experimental plots at seven sites, representing different agricultural zones of Kenya, over four seasons. Helicoverpa armigera (Hübner) (formerly Heliothis armigera) only occasionally achieved population densities sufficient to cause obvious damage to the crops, and was virtually absent from the coastal sites. At the inland sites, infestation and mortality levels varied greatly. Information is presented on the incidence of H. armigera, and the identity, distribution and frequency of its common parasitoids and (potential) predators, sampled in the experimental plots. Trichogrammatoidea spp., egg parasitoids, and Linnaemya longirostris (Macquart), a tachinid late-larval parasitoid, were the most common parasitoid species, but total percentage parasitism was rather low. Of the large complex of predators, only anthocorids and ants (predominantly Pheidole spp., Myrmicaria spp. and Camponotus spp.) were sufficiently common and widespread to be of importance in suppressing H. armigera. The abundance of predators fluctuated widely between sites, but anthocorids were most abundant at the western sites.

Whilst investigating the biology of parasites of the frit-fly (Oscinella frit, L., Diptera, Chloropidae) in North America with a view to introducing possible species for the biological control of this pest in Great Britain, extensive experimental work was done with one species of Chalcid, Spalangia drosophilae, Ashm. (Spalangidae), a parasite of frit puparia. During this work conditions inducing a state of diapause in the mature larvae were investigated. As with many other species, it was found that low temperatures during development favoured entry into diapause, whilst high temperatures favoured emergence of the progeny without arrest in development. However, other factors were found to have some important bearing in this respect. Some individual females produced progeny, all of which entered a state of diapause in the full-grown larval stage, others bred and ovipositing under identical conditions produced progeny all of which emerged without arrested development, others produced progeny that were mixed in this respect. This effect did not seem to be inheritable. The history of each individual female with respect to environmental conditions was found to have an important influence on the propensities of her progeny for entering diapause. These effects will be dealt with more fully at a later date. There was, however, one striking effect which has apparently not been noted before, and which it was felt was of sufficient interest to be recorded separately.