For over a century, scientists from industrialized countries as well as from developing countries have appropriated natural enemies from different regions of the world. These actions have been conducted thus far without compensation to the donor countries for such ‘biological services’. This unrecompensed extraction has been predicated on the basis that biodiversity (including natural enemies) are ‘humankind's common heritage’ (Kloppenburg & Kleinman, 1987). Such a view has been challenged by some social scientists as well as representatives from some developing countries who now question the inequity of global patterns of exchange of and access to plant genetic resources. At issue is the substantial ‘genetic debt’ that the industrialized countries have procured from developing countries and which has remained uncompensated (Fowler & Mooney, 1990). In fact, the agricultures of industrialized countries are characterized by extreme dependence on ‘introduced’ genetic materials from developing countries. Much of this germplasm has been utilized by seed companies from industrialized countries to develop new, high-yielding varieties, often sold back to developing countries at considerable profit. The contradiction in the status of developing countries crop genetic resources as freely available ‘common heritage’ and the status of seed companies’ commercial varieties as ‘private property’ available by purchase has fueled a major geopolitical controversy. This dispute is bound to expand to other activities involving interregional exchange of biological resources. Concern about global environmental changes, the levels of responsibility of industrialized and developing countries in relation to these changes, and the fact that many developing countries are major repositories of biodiversity which play major biospheric roles, are all issues that fuel the controversy.

Hollow-fibre, microencapsulated and twist-tie formulations of the pheromone of the pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) were used in trials conducted in Pakistan from 1985–1988. Early season control of this pest by mating disruption, permitted an average reduction of two applications, of conventional insecticides otherwise required to control the cotton pest complex, particularly at the time of flower and fruit setting when beneficial insects are most numerous. The pheromone formulations, together with a mixture of selective and broad-spectrum insecticides in plots of 5 or 10 ha of cotton were compared with plots of cotton, of similar size in the same locality treated with a conventional insecticide spray programme and in plots where no insecticide applications were made for the control of bollworms. Comparisons of numbers of infested bolls and estimated yields showed that levels of control achieved using the pheromone/insecticide combinations were equal in effect to conventional programmes of insecticide sprays, whereas in plots where no bollworm control measures were taken, significantly higher bollworm infestations and reduced yield estimates were recorded.

Infestations of pink bollworm, Pectinophora gossypiella (Saunders), (Lepidoptera: Gelechiidae), and numbers of beneficial insects in two cottons, Gossypium hirsutum, were compared at Maricopa, Arizona, and Brawley, California, during the 1986–1988 seasons. Plots (0.8 ha) of WC-12NL (nectariless, okraleaf, and early maturing) had significantly lower boll infestations than DPL-61 (nectaried, normal leaf, and later maturing) for each location and year. The three year average (range) PBW/100 bolls for WC-12NL and DPL-61 at Maricopa were 6.8 (5.7–10.7) compared to 11.2 (6.8–15.7), respectively. At Brawley the averages were 18.9 (9.3–27.6) compared to 39.2 (15.5–52.5), respectively. With the exception of 1986 at Maricopa, the percentage of bolls with eggs was significantly greater for DPL-61 (average 8.1, range 3.4–16.0) than for WC-12NL (average 4.2, range 1.1–12.1) for each location and year. Both cottons averaged about four eggs per oviposited boll; not significantly different. The numbers of Lygus spp. and three beneficial species of insects were not different in the two cottons. Collops vittatus (Say) (Coleoptera: Melyridae) was collected in significantly greater numbers in WC-12NL (1.0 per 50 sweeps compared to 0.9 for DPL-61), while Hippodamia convergens (Guérin-Ménéville) (Coleoptera: Coccinellidae) was collected in greater numbers in DPL-61 (0.6 per 50 sweeps compared to 0.3 for WC-12NL). WC-12NL is the culmination of a 20-year breeding programme for resistance to P. gossypiella and has characteristics attractive for cotton production in areas where a shorter growing season is desirable.

Growth of larvae of the whitefringed weevil, Graphognathus leucoloma (Boheman), was studied in the laboratory and on various crops in pots in a shadehouse at Kairi, on the Atherton Tableland in north Queensland. In the laboratory at 25.5 ± 1°C there were 11 instars for which head capsule widths and weights were recorded. The first instar weighed 0.14 mg. This was a non-feeding stage capable of prolonged survival, and after 10 weeks in soil without food 60% survived. When provided with carrot (Daucus carota) larvae grew to 2 or 3 mg after 6 to 7 weeks, then increased rapidly in weight reaching 140 mg after 120 days. At 25.5°C the average time from first instar to adult was 311 days, due in part to a long prepupal period. Larval growth was measured on the roots of peanut (Arachis hypogaea) plants in pots in summer and winter. Under summer conditions (mean soil temperature 23.3°C) larvae reached 140 mg in about 120 days, similar to that in the laboratory on carrot. These fully grown larvae remained in the pots over the mild winter without pupating. Larvae developing in autumn/winter grew more slowly, but the fully grown larvae were then exposed to high spring (early summer) temperatures and soon pupated, the average time from first instar to adult being 273 days. The indications are that temperatures above 25°C quickly precondition mature larvae from Tolga for pupation, thus explaining the broad timing of adult emergence in the field in north Queensland. On different plants common near Tolga, larvae grew most quickly on peanuts and on the pasture legumes dolichos (Lablab purpureus) and stylosanthes (Stylosanthes guianensis). Survival on maize equalled that on peanuts (46.5% in sterilized soil) but growth was less. Larval survival and growth on the grass crowsfoot (Eleusine indica), and (surprisingly) on the pasture legume glycine (Neonotonia wightii) was very poor.

Female oriental armyworm moths, Mythimna separata (Walker), emerged without discernible oocytes in the ovarioles, and reproductive maturity, on the criterion of onset of calling behaviour, was associated with an intermediate stage of oocyte development. Ingestion of carbohydrate was required for completion of oocyte development in the majority of females although a proportion matured when allowed only water. Among females kept alone, these were exclusively moths from a strain selected for early onset of calling but, in the presence of a male, a few females from an unselected line also called and achieved oocyte maturation, without access to carbohydrate. Thus factors other than ovarian development apparently influence the commencement of calling. The absence of an effect of carbohydrate uptake on pre-calling period supports a previous conclusion that this trait is determined primarily by genetic components in this species. It is concluded that ingestion of carbohydrate is important for the attainment of reproductive maturity in M. separata but that it has a differential effect in early and later-calling genotypes. The implications of the results for the reproductive and migratory strategies of M. separata, an important agricultural pest, are discussed.

Chlorphoxim resistance is found in forest strains of Simulium sanctipauli Vajime & Dunbar, in some areas of the Onchocerciasis Control Programme in West Africa. There is an increase in esterase activity in both adults and larvae in the resistant compared to the susceptible strain with the general esterase substrate 1-naphthyl acetate. This appears to be associated with the temephos and chlorphoxim resistance which are found in the same resistant strain. It is possible that one or more esterases are qualitatively and/or quantitatively changed in the resistant strain compared to the susceptible. Preliminary studies indicated that esteratic hydrolysis and oxidative cleavage were both involved in chlorphoxim metabolism in S. damnosum Theobald sensu latu. There was evidence of an increase in detoxication by both these routes in the resistant compared to the susceptible strain of the cytospecies S. sanctipauli. The increase in oxidative detoxication seen in the resistant strain was associated with a slight, but non-significant increase in cytochrome P450 as measured by the sodium dithionite reduced carbon monoxide difference spectra.

The arthropod community associated with irrigated rice grown in five sites in Luzon Island, Philippines, was analysed using guild categories. Phytophages and predators were predominant in all sites. The phytophage species were mainly Homoptera and dominated by Nephotettix virescens (Distant), N. nigropictus (Stål) (Cicadellidae), and Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Delphacidae). Predators were mainly Heteroptera with Microvelia douglasi atrolineata Bergoth (Veliidae), Mesovelia vittigera (Horváth) (Mesoveliidae), and Cyrtorhinus lividipennis Reuter (Miridae) as the most abundant species. Spiders were the next dominant group with Pardosa pseudoannulata (Böesenberg & Strand) and three species of Tetragnatha the most common. Differences in species diversity between the sites were easily differentiated using diversity indices. The relative differences in arthropod abundance, species richness and diversity may be attributed to the median temperatures, cropping patterns, and diversity in crop stages and germplasm in the sites. Predator-Homoptera correlations were significant in all cases. High positive correlations were obtained for veliids, spiders and Cyrtorhinus lividipennis, in most sites.

Dispersal of apterae from their natal plant was monitored for three aphid species (Myzus persicae (Sulzer), Brevicoryne brassicae (Linnaeus) and Megoura viciae Buckton), each on a different host plant. Some movement off the plant occurred even in the initial parental and second generations, when the plant appeared to be growing normally and when crowding was unlikely to be the cause. However, in most experiments the most marked increase in apterous dispersal coincided with a reduction or even cessation of plant growth. In nearly all the experiments this dispersal occurred when the population on the natal plant exceeded about 20 adults and their offspring per plant. The main emigrants were fourth instar apterae and prelarviposition adult apterae. The implications of this behaviour are discussed, and it is argued that apterous dispersal might be common in aphids, allowing a fuller utilization of the environment than would be likely by alate dispersal alone.

The parasitoid complex and apparent parasitism of Choristoneura murinana Hübner were investigated in relation to the relative abundance of budworm larvae at several sites in Europe. A single outbreak population was sampled, while other sites supported varying but much lower host population abundance. Sampling at Sion in Switzerland from 1984–89, indicated that the species richness of the parasitoid complex was correlated with relative host abundance and in general more polyphagous parasitoids were represented in sites with greater budworm abundance. Of the specialized parasitoids, Apanteles murinanae Čapek & Zwölfer (Hymenoptera: Braconidae) was dominant in less abundant host populations and both Cephaloglypta murinanae (Bauer) and Dirophanes maculicornis (Stephens) (Hymenoptera: Ichneumonidae) were supported only at greater budworm abundance. These findings are discussed in relation to the use of Choristoneura murinana parasitoids in the biological control of native Choristoneura spp. pests in other continents.

Subperiodic filariasis (Brugia malayi) infections are endemic in the State of Sarawak, Malaysia, along the coastal villages and rural communities where the mosquitoes Mansonia bonneae Edwards, M. dives (Schiner) and M. uniformis (Theobald) are the main vectors. Two ecologically similar villages, Kampung Ampungan and Kampung Sebangkoi, were selected for comparison of the three Mansonia spp. in terms of their entomological baseline data, namely biting activity, survival and infective rates. Data obtained on their annual transmission potential (ATP), annual infective biting rate (AIBR) and vectorial capacity (C) showed M. bonneae to be the principal vector of B. malayi infections in Sarawak. Survival rates of M. bonneae and M. dives were estimated using both the exponential model of Macdonald which assumes an age-independent survival rate and the Gompertz model which assumes a decrease in the survival rate with advancing age of female mosquitoes.

The distribution of Rastrococcus spp. within mango trees (Mangifera indica) was studied at Bangalore, India. Population densities of R. invadens Williams, R. iceryoides (Green) and R. mangiferae (Green) were significantly higher on the abaxial leaf surface compared with the adaxial surface. Mealybug density was also higher from ground level up to 2 m compared with above 2 m. Significant variations in Rastrococcus spp. populations among trees and species composition per tree were observed. As populations built up on leaves, migration to other leaves occurred, more predominantly in R. mangiferae than in R. invadens. As the population of R. iceryoides increased on leaves, migration to twigs occurred.

The attack rate of four parasitoids against different aphid species was investigated in the absence and presence of leaves from aphid food plants. The parasitoids used, Aphidius ervi Haliday, A. rhopalosiphi De Stefani, A. picipes (Nees) and Ephedrus plagiator Nees, varied in the extent of their host ranges. The presence of plant leaves significantly influenced the attack rate of A. ervi and A. rhopalosiphi, the two parasitoids with the most restricted host ranges, but did not appear to affect attack rates by the more polyphagous A. picipes and E. plagiator. Consideration of these results together with those from previous studies on the host preferences of laboratory populations of A. ervi and A. rhopalosiphi leads to the conclusion that genotype is probably determining the responses of individual parasitoids to semiochemicals involved in host recognition. It is proposed that field populations of oligophagous aphid parasitoids consist of a mixture of specialist and generalist individuals.

Samples of Glossina longipennis Corti, taken over four days in traps (baited with acetone, cow urine and octenol) at half-hourly intervals during their restricted activity periods at dusk and dawn, were analysed for their nutritional condition. For both sexes, trap catches were highest at the end of dusk, between 19.00 and 19.30 h, associated with a significant increase in numbers with the low haematin content characteristic of flies estimated to have fed more than 60 hours previously. Also, the mean fat content of these flies was significantly lower than that of those trapped earlier. There was considerable day-to-day variation in the numbers of flies trapped, and in the numbers of low haematin and low fat flies. It is concluded that the nutritional condition of the fly probably influences the timing of the onset of activity, but possibly the fly's approach to the trap.

The taxonomy of the Oriental species of Helopeltis is revised and a review of the economic literature is given. An identification key is provided for the 14 recognized species, one of which, H. sulawesi, is described as new. A diagnosis and brief description is given for each species, as well as illustrations of useful taxonomic characters, information on distributions and host records, and a discussion of any known or suspected misidentifications. Lectotype designations are made for 13 nominal species and the following new synonymies are established: H. bradyi Waterhouse = H. ceylonensis De Silva, syn. n and H. romundei Waterhouse, syn. n;H. cinchonae Mann = H. brevicornis Poppius, syn. n.;H. clavifer (Walker) = H. australiae Kirkaldy, syn. n and H. niger Walker, syn. n;H. cuneata Distant = H. elegans Poppius, syn. n;H. fasciaticollis Poppius = H. pallidus Poppius, syn. n and H. pallidiceps Poppius, syn. n;H. theivora Waterhouse = H. oryx Distant, syn. n The somewhat obscure synonymy of H. theobromae Miller under H. theivora is confirmed. Two subgenera are recognized and diagnosed: Afropeltissubgen. n (type species Eucerocoris westwoodi White), including all African species of the genus, and Helopeltis sensu stricto, containing the Oriental and Australasian species.

The Old World screw-worm fly, Chrysomya bezziana Villeneuve, occurs in Africa, the Middle East, Malaysia, Indonesia and Papua New Guinea, but it is not found in Australia. Introduction into Australia from any of these source areas would threaten the viability of much of the grazing industry in the northern part of the continent. Proposed control by the sterile insect release method (SIRM) would be compromised by the existence of sibling species within C. bezziana. This study examines the degree of genetic differentiation throughout the extensive range of the fly to assess if the degree of geographic differentiation indicates the existence of sibling species and, allows identification of the source of any introduced flies. Electrophoretic analysis of 23 loci from samples collected in southern Africa, the Middle East, Malaysia, Indonesia, and Papua New Guinea revealed 11 polymorphic loci. Overall, populations show remarkably little divergence given the geographic distribution of sample sites. None of the populations sampled were fixed for alternative electromorphs. There is no evidence from this study for the presence of sibling species within C. bezziana.