The development of infestations of Pseudaulacaspis pentagona (Targioni-Tozzetti) on passion fruit vines in Western Samoa was monitored at two sites over a period of 20 months, during which the aphelinid parasitoids Encarsia berlesei (Howard) and E. diaspidicola (Silvestri) were released. All vines were rated for P. pentagona infestations, and the female scale insects were counted on selected vines. At one site, the numbers of P. pentagona built up to over 10 000 adult females per vine before the parasitoids became established, and within one year 50% of the vines died. At the other site, where vines survived, an endemic coccinellid predator, Sticholotis quadrisignata Weise, kept populations below 3000 females per vine until the parasitoids became established. Biological control of P. pentagona was achieved at both sites eight months after the parasitoids were introduced. A model for interaction of P. pentagona and parasitoids predicted higher levels for parasitization than revealed by microscopic examination.

A cheap power pack that could be run off a 12-V car battery was constructed using a 12–250–V DC-DC converter. The power pack is small and light and can be used to run a Helena cellulose acetate electrophoresis system away from a mains electricity supply. The system was used sucessfully to identify adults of the Simulium damnosum Theobald complex in a field laboratory in northern Sierra Leone.

The responses of individually marked males of Glossina morsitans morsitans Westwood to decoys (9 × 3-mm rectangles of 2-mm-thick brushed nylon) baited with sex pheromone (15,19,23-trimethylheptatriacontane) were studied after their release onto an island in Lake Kariba, Zimbabwe. Some 45–60% of resighted flies were seen on decoys, the percentage being greater for flies released at an older age. For flies released on emergence, the mean age at first contact with decoys on a static screen was 6.6 days, an average of four days later than their first observed contact with a bait ox. There was great variability in the response towards decoys on successive contacts. In general, the intensity of the responses to decoys in the first minute after contact (the ‘pre-copulatory’ responses) decreased from one enounter to the next in a single 1–2-h observation session, but were restored to high levels after an interval of several hours. The intensity of responses towards decoys after this initial period (the ‘copulatory’ responses) were not affected by previous contacts. Neither previous sexual experience nor age at first contact affected the durations of response on decoys. There were no differences between the responses of wild flies and those from a laboratory colony. The results are discussed in relation to the use of decoys with chemosterilant for tsetse autosterilization. Over 60% of flies contacting decoys did so more than once, which would increase, cumulatively, the chances of their being sterilized.

Studies were conducted in Zimbabwe to determine the nature and degree of sexual responses of males of Glossina morsitans Westwood and G. pallidipes Austen around host animals, traps and targets. Males of both species, after being attracted, appeared to accumulate around a stationary bait. This was supported by observations of concentrations of unfed males of G. m. morsitans on bait animals and unfed males of G. pallidipes on the surrounding ground. Nutritional analysis confirmed that traps attract males with a range of hunger states but catch mainly hungry males of both species. Movement of electrified targets significantly increased the catches of both sexes of G. m. morsitans but not of G. pallidipes. Artificial female-mimicking decoys made from black felt sewn onto electrified targets significantly increased the numbers of G. m. morsitans males caught when the targets were stationary and of G. pallidipes males when they were moving. The electrified targets caught a higher proportion of males of both species than traps, most probably as a result of their killing the males accumulating around the target in search of virgin females. The results show that the behaviour of relatively well-fed males attracted to host animals, traps and targets does appear to have a sexual component in both G. m. morsitans and G. pallidipes and that it may be possible to exploit the sexual responses of males to increase capture efficiency further. However, targets may have far greater potential for such manipulation than traps.

An airborne radar system able to measure insect density profiles and the orientation of individual insect targets was developed using standard components. Using the system, typical moth targets, with a radar cross-section of 1 cm2, can be detected to a range of about 1 km. Signals from 48 separate height bands, each 15 m deep, are recorded on three analogue data channels. Analogue outputs related to aerial population per hectare can be viewed in real-time. Signals recorded during recent field work show an inclined layer over a track length of 30 km, with target orientation profiles at two positions along the layer. The strongest orientation occurred in regions of wind shear. Airborne entomological radar powerfully complements existing techniques by virtue of its mobility, providing unique opportunities to study the spatial organization of migration, to track features as they develop and to survey large areas.