Larval responses of Delia radicum (Linnaeus), D. floralis (Fallén) and D. antiqua (Meigen) to plant volatiles were measured using a behavioural assay. Larvae were attracted to their host-plant, but non host-plants either had no effect or were repellent. Testing of individual secondary plant volatiles indicated that larvae were attracted to secondary plant volatiles from their host-plant, but were neither attracted nor repelled by secondary plant volatiles from non host-plants. A general plant volatile did not have this effect.

Two bioassays were conducted in parallel to assess the effects of cattle treated with either 1% ivermectin (IVM) or 3.15% IVM (dosed at 0.2 and 0.63 mg kg−1, respectively) on reproduction and survival of Onthophagus landolti Harold. Adult beetles were exposed 10 days to faeces of treated cattle starting at: one day before treatment (controls), 3, 6, 14, 28 and 35 days post-treatment. Adult survival of O. landolti was not affected by either of the two treatments. Faecal residues of 1% IVM almost completely suppressed fecundity of beetles at 3, 6 and 14 days post-treatment (dPT), and reduced fecundity of O. landolti at 28 dPT ( 38.3%), relative to controls. Meanwhile, IVM residues after treatment with 3.15% IVM almost completely suppressed fecundity of beetles at 3, 6, 14 and 28 dPT, and reduced fecundity of O. landolti at 35 dPT (80.9%), relative to controls. Larval survival was significantly reduced only at 3 dPT with 1% IVM. Meanwhile, treatment with 3.15% IVM significantly reduced larval survival at 6, 14 and 28 dPT. Larval mortality was recorded only in L-I and L-II instars. Moreover, in both bioassays, most of the L-I and L-II specimens that survived showed signs of toxicity. In conclusion, residual IVM in cattle faeces after treatment with injectable IVM has a detrimental effect on the fecundity of adult O. landolti up to 4 weeks post-treatment and on the subsequent larval survival.

The host ranges of a collection of 21 tick species found on wild mammals in the savanna, forests and coastal zone of Ghana suggested that most species were adapted to feeding mainly on host species within a single mammalian order, i.e. on artiodactyls (bovids/suids), carnivores, rodents or pholidotes (pangolins). Only a few species were dispersed evenly across a range of orders. Seven out of ten of the most common ticks on forest mammals were significantly associated with a particular host species or a group of closely related host species, which could be viewed as their major host or hosts, but they were also recorded much less frequently on a wide range of host species. Two other species were confined to their major hosts. Only one species appeared to be widely dispersed on forest mammals and to lack a particular major host. The majority of tick species therefore occurred on hosts with very distinctive biological, behavioural and ecological characteristics. The study provided no evidence to support the view that host specificity is an artefact of sampling. Finding that the tick species on Ghanaian wild mammals occurred on particular hosts, as well as in distinct habitats, indicated that tick–host associations are important for tick survival and confirmed the importance of climate and vegetation in tick distribution.

Descriptions are given of 24-hour biting catches, made in and around Faza, a village on Pate Island, off the north-east coast of Kenya, East Africa.

Aedes pembaensis Theo. was the predominant mosquito in these catches but fair numbers of Aedes mombasaensis Mattingly were also taken; the biting cycles of these two are discussed. Six other species were taken in small numbers.

For Ae. pembaensis, biting cycles calculated on catches grouped for site, moon phases, neap tides and spring tides show that both moon and tide and light intensity influence the biting behaviour. Different but recurring patterns occur with various combinations of these factors.

For Ae. mombasaensis, the cycles have a very constant biphasic pattern. Catches grouped for moon phases, tides and catch sites, as for Ae. pembaensis, show that more biting females are taken at neap tides than at spring tides. Two patterns of behaviour occur, one associated with spring tides and the other with neap tides. An even level of biting activity occurs during the night with intense and prolonged moonlight; otherwise moon-phase cycles have little effect on biting behaviour.

It is felt that 24-hour biting catches can give useful information on behaviour patterns but it is desirable to have a long series of catches to analyse. For the purpose of calculating biting cycles, the results of catches showing similar modifications in behaviour should be treated separately.

Conwentzia psociformis (Curt.) and Conwentzia pineticola End. differ as adults in only two characters, and since there are variable and intermediate forms occur, reliable determination is sometimes impossible. In the past, these two species have often been regarded as two forms of the same species.

The immature stages of C. pineticola are, however, very different from those of C. psociformis and show that the two are distinct species and can readily be separated on larval characters. The larval stages and egg of C. pineticola are described for the first time, and an account of its life history given.

The feeding habits of these two species are described, and mention is made of two other Coniopterygid species that occur in orchards.

Conclusions concerning the distribution and field habits of Anthrenus verbasci (L.), A. fuscus Ol. and A. museorum (L.), are based upon the results of three surveys.

The first survey comprised the collection of adults of Anthrenus from attractive flowers, e.g., hogweed, Heracleum sphondylium, in various localities furing June and July. This showed that:—

A. Verbasci occurred in large numbers only in the suburban areas of south-east England, extending also to the west along the south coast.

A. fuscus was generally distributed in all types of locality in the south reaching a peak abundance in the vicinity of farms. Its members diminished rapidly towards the north.

A. museorum occurred in small numbers only, often accompanying A. fuscus.

The second survey comprised the collection of larvae from natural habitats and included results from an earlier survey of certain birds' nests. This showed that:—

A. verbasci was characteristically an inhabitant of dry birds' nests.

A. fuscus was usually found feeding on dead insects around spiders' webs, under the bark of trees, etc.

A. museorum occurred in small numbers in company with A. fuscus.

The habitat difference between A. verbasci and A. fuscus was sharply defined. Only very rarely was one sspecies found in the habitat typical of the other.

In order to estimate the effect of cracks in floors upon the oviposition rate of Calandra granaria (L.) in an unstocked granary, grain was presented to adults in six ways. The grain was either fixed or loose. Fixation was achieved either by placing grain in cracks in wood or plaster of Paris, or by gumming (in rows or scattered) to glass. The loose grains lay upon glass or plaster of Paris.

A significantly greater number of eggs was laid upon grain that was fixed. The fact that the grains were in rows and partially enclosed when in cracks had no greater effect than fixing with gum. There was no significant departure from a random distribution of eggs in grains when the latter were in cracks.

Independent discoveries of an Aphid attacking the roots of rice and other Gramineae in different parts of the world have led to its description under different names, and its affinity with other species has sometimes resulted in its confusion with them. The literature relating to the species is reviewed and it is shown that the correct name for it is Rhopalosiphum rufiabdominalis (Sasaki), of which Prunus is the primary host.

What is believed to be a reasonably complete synonymy is given and this involves the sinking of the two genera Yamataphis Matsumura and Aresha Mordvilko as synonyms of Rhopalosiphum Koch because both of these genera were erected with the Rice Root Aphid as type. A species that was described as Yamataphis rhodesiensis Hall differs in too many respects to permit its inclusion in Rhopalosiphum and a new genus, Hallaphis, is erected for its reception.

In my recent revision of the mosquitos of the Australasian region the following species were mentioned as occurring in the Solomon Islands, the specimens having been for the most part collected by Dr. A. G. Carment:

Anopheles (Myzomyia) punctulatus, Dön.

Helicoverpa armigera (Hübner) and H. punctigera (Wallengren) are major pests of cotton in Australia. The density of eggs and larvae of these species are sampled regularly throughout the growing season to assess the need for insecticidal control. A sampling system now widely used is based on binomial sampling combined with a series of conversion relationships developed as part of the SIRATAC computer based pest management system established in the early 1980s. A three year study was initiated to reassess the binomial sampling conversion relationship in the light of changed agronomic practices and new cotton varieties. New relationships were established to predict the mean number of Helicoverpa spp. present, based upon the number of infested plants found within a sample. Relationships are reported for the sampling of whole plants and the sampling of the terminal (top 20 cm) portion of cotton plants only. These new relationships will be incorporated into entomoLOGIC, a personal computer based pest management system now released to replace SIRATAC.

In this study, an orthogonal array design with 16 factors at two levels (216) was performed to develop an artificial diet rearing the adults of seven spotted ladybird beetle Coccinella septempunctata. The parameters of weight gain and survival rate of adults, preoviposition period, fecundity and hatching rate of diet-fed adults were monitored. The 16 factors were included: pork liver, infant formula, sucrose, olive oil, yolk, corn oil, yeast powder, cholesterol, casein, casein hydrolysate, vitamin powder, 65% juvenile hormone III, protein powder, vitamin E, honey and pumpkin. Results indicated that pork liver, sucrose, yolk, yeast powder, juvenile hormone, pumpkin and honey were the main ingredients of the artificial diet contributing to weight gain and survival rate of adults, preoviposition period, fecundity and hatching rate. A follow-up fed with a selection of improved formulas confirmed the validity of the optimization as predicted by the orthogonal array analysis, indicating the usefulness of this method for selecting artificial diets for C. septempunctata. The weight gain and fecundity of adults reared on the improved artificial diet were 87.46 and 62.70% of those reared on Aphis craccivora; the survival rate and hatch rate were similar between the diet-fed and aphid-fed, while the preoviposition period was significantly shorter for C. septempunctata fed on the diet than on A. craccivora. The latter formula was superior to any formerly developed formulas and may thus have potential for the improved artificial diet mass rearing of C. septempunctata.

Extreme high-temperature events are the key factor to determine population dynamics of the rice leaf folder, Cnaphalocrocis medinalis (Guenée), in summer. Although we know that adult of this insect can migrate to avoid heat stress, the behavioral response of larva to high temperature is still unclear. Therefore, impacts of high temperature on behavioral traits of C. medinalis including host choice, settling and folding leaf were observed. The results revealed that these behavioral traits were clearly influenced by high temperature. The larvae preferred maize leaves rather than rice and wheat at normal temperature of 27°C, but larvae experienced a higher temperature of 37 or 40°C for 4 h preferred rice leaves rather than maize and wheat. Capacity of young larvae to find host leaves or settle on the upper surface of leaves significantly reduced when they were treated by high temperature. High temperature of 40°C reduced the leaf-folding capacity of the third instar larvae, but no effects were observed on the fourth and fifth instar larvae. Short-term heat acclimation could not improve the capacity of the third instar larvae to make leaf fold under 40°C.

Although the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) is the most destructive insect pest of coffee worldwide, there is much to learn about its thermal biology. This study aimed to develop temperature-based models for H. hampei development and to provide the thermal requirements of immature stages in the laboratory. Using a new observation method, larval development and survival were monitored daily on fresh Arabica coffee seeds, under seven constant temperatures in the range 15–35°C, with 80 ± 5% RH and 12:12 L:D photoperiod. Linear and non-linear functions were fitted to the development data plotted against temperature, using Insect Life Cycle Modelling software (ILCYM). Temperature significantly affected the development time of all immature stages. Egg incubation period ranged 4.6–16.8 days, under temperature between 30 and 15°C. No development occurred at 35°C and the larval stage did not develop to pupa at 15°C. The minimum temperature threshold (Tmin) estimated from linear regression was 10.5, 13.0, 15.0 and 13.0°C, for egg, larva, pupa and the total development from egg to adult, respectively. The maximum temperature threshold (Tmax) estimated from the Sharpe and DeMichele function was 32°C for egg to adult development. The thermal constant (k) was estimated at 78.1, 188.7, 36.5 and 312.5 degree days, for egg, larva, pupa and for egg to adult, respectively. Our results will help understand and predict the pest population dynamics and distribution in coffee plantations as impacted by temperature, and as such, will contribute to a more efficient management of the pest.

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.

The taxonomic status of the Culex vishnui group of species is discussed. Three species belonging to this group, C. vishnui Theo., C. pseudovishnui Colless and C. tritaeniorhynchus Giles, were recognised in the study area near Vellore, South India. All three species are described on the basis of adults and larvae, and keys for the identification of adults are provided.

The Colony of Southern Nigeria was traversed by the writer in 1910, and the following short report is founded on observations made during the first seven months of that year. As will be seen later on, various officers, chiefly medical, stationed in the Colony, afforded material help in the investigation, and the results of their work are also incorporated here; the collections of injurious insects made by them have been duly acknowledged in previous issues of this Bulletin, and also, as far as possible, throughout this report.

In the present work, we carried out a morphological, biometrical and molecular study of the species Archaeopsylla erinacei (Bouché, 1835) and their subspecies: Archaeopsylla erinacei erinacei (Bouché, 1835) and Archaeopsylla erinacei maura (Jordan & Rothschild, 1912) isolated from hedgehogs (Erinaceus europaeus) from different geographical regions (Seville and Corse). We have found morphological differences in females of A. erinacei from the same geographical origin that did not correspond with molecular differences. We suggest that some morphological characters traditionally used to discriminate females of both subspecies should be revised as well as we set the total length of the spermatheca as a valid criterion in order to discriminate between both subspecies. The Internal Transcribed Spacers 1 and 2 (ITS1, ITS2) and partial 18S rRNA gene, and partial cytochrome c-oxidase 1 (cox1) and cytochrome b (cytb) mtDNA gene sequences were determined to clarify the taxonomic status of these taxa and to assess intra-specific and intra-population similarity. In addition, a phylogenetic analysis with other species of fleas using Bayesian and Maximum Likelihood analysis was performed. All molecular markers used, except 18S, showed molecular differences between populations corresponding with geographical origins. Thus, based on the phylogenetic and molecular study of two nuclear markers (ITS1, ITS2) and two mitochondrial markers (cox1 and cytb), as well as concatenated sequences of both subspecies, we reported the existence of two geographical genetic lineages in A. erinacei corresponding with two different subspecies: A. e. erinacei (Corse, France) and A. e. maura (Seville, Spain), that could be discriminated by polymerase chain reaction-linked random-fragment-length polymorphism.

Population cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation in O. brumata cycle amplitude results from climate-induced variation in the degree of phenological matching between trophic levels, possibly between moth larvae and parasitoids. The likelihood of mismatching phenologies between larvae and parasitoids is expected to depend on how specialized parasitoids are, both as individual species and as a guild, to attacking specific larval developmental stages (i.e. instars). To investigate the larval instar-specificity of parasitoids, we studied the timing of parasitoid attacks relative to larval phenology. We employed an observational study design, with sequential sampling over the larval period, along an altitudinal gradient harbouring a pronounced treeline outbreak of O. brumata. Within the larval parasitoid guild, containing seven species groups, the timing of attack by different groups followed a successional sequence throughout the moth's larval period and each group attacked 1–2 instars. Such phenological diversity within parasitoid guilds may lower the likelihood of climate-induced trophic mismatches between victim populations and many/all of their enemies. Parasitism rates declined with increasing altitude for most parasitoid groups and for the parasitoid guild as a whole. However, the observed spatiotemporal parasitism patterns provided no clear evidence for or against altitudinal mismatch between larval and parasitoid phenology.

Independent studies were performed in Canada and in Denmark to assess the survival of parasitic wasps (Hymenoptera: Pteromalidae) wintering in puparia of house fly, Musca domestica Linnaeus (Diptera: Muscidae). Data in Canada were collected for Muscidifurax raptorGirault & Saunders, M. raptorellus Kogan & Legner, M. zaraptor Kogan & Legner, Nasonia vitripennis(Walker), Spalangia cameroniPerkins, Trichomalopsis sarcophagae (Gahan) and Urolepis rufipes (Ashmead) in three microsites at an outdoor cattle facility in southern Alberta. Survival was highest for N. vitripennis, T. sarcophagaeand U. rufipes, ranging from near zero to c. 7%. No survival was observed for S. cameroni. Daily mean values for ambient air temperature (DMAT) averaged about −3.5°C during exposure periods. Data for Denmark were collected for M. raptor, S. cameroniand U. rufipes in a dairy barn and in a swine barn. Survival of M. raptorand U. rufipes was higher than that of S. cameroniin the dairy barn (DMAT = 8.6°C), with the three species having similar survival in the swine barn (DMAT = 15.4°C). In both studies, parasitoids in egg stages were least likely to survive. These results identify the potential for T. sarcophagae and U. rufipes to be commercialized for use in northern climates as biocontrol agents for nuisance flies, compare directly the cold-hardiness of commercialized species (i.e. all of the above species excluding T. sarcophagae and U. rufipes), and document the importance of microsite on winter survival.

The laboratory studies were conducted to uncover the correlation between the levels of pyrethroid resistance and the reproductive potential of parent (SS) and resistant strains of Culex quinquefasciatus (RR) originating from Delhi, India and selected with deltamethrin (RDL) or the combination of deltamethrin and PBO (1:5) (RDP) at the larval stage and selected with deltamethrin at the adult stage (RDA). The reproductive potential was evaluated in terms of fecundity, fertility, egg hatchability and longevity of gonotrophic cycles. The RR strains exhibited 68–74% reduced duration of the gonotrophic cycles when compared with that of SS strain. The considerable decrease in the egg production, ranging from 45.4% to 61.6%, observed in the selected strains as compared to the SS strain, indicates the possible positive correlation between the levels of deltamethrin resistance and the reproduction disadvantage. This correlation was further confirmed by 24.6% to 53.6% decrease in the hatchability of eggs of the selected strains with respect to that of the parent strain. A worth-mentioning observation of the reduced reproductive fitness in RDP strains suggests the effectiveness of synergized deltamethrin selections in reducing the frequency of resistant individuals. The reproductive disadvantage in adult-selected strains possessing negligible resistance to deltamethrin implicates the efficacy of deltamethrin as an adulticide rather than as a larvicide against Cx. quinquefasciatus. The results suggest that the reduced reproductive fitness of resistant genotypes in the population can eliminate heterozygotes and resistant homozygotes by implementing different resistance-management strategies against Cx. quinquefasciatus.