Catches by gypsy moth (Lymantria dispar (Linnaeus)) ‘milk-carton’ pheromone traps with (+)-disparlure were compared with estimates of the absolute aerial density of gypsy moths obtained using a suction trap of known absolute sampling efficiency. The mean number of male L. dispar caught per pheromone trap per day was found to be proportional to the 2/3 power of the suction trap's estimate of aerial density. We infer that the efficiency of the gypsy moth milk-carton pheromone trap is density-dependent, declining as aerial density increases. The significance of the density-dependent efficiency and the mode of action of attractant traps are discussed, and the problems of designing and building suction traps to standardize pheromone traps for other species are also considered. It is concluded that standardization is only possible when some basic biology is known because pheromone trap parameters are specific to the field behaviour of the species.

Data from dung-baited pitfall traps show that dung beetles (Coleoptera: Scarabaeidae) do not discriminate against dung from sheep or cattle treated with avermectin. On the contrary, for a period post-treatment, dung from animals treated with avermectin attracted more beetles than dung from untreated animals. This effect was more marked with cattle dung than with sheep dung. The period of enhanced attractiveness of sheep dung was restricted to dung produced during the first day after treatment, whereas with cattle dung, the effect was still evident in faeces produced 25 days after treatment. Cattle dung produced from 3–25 days post-treatment caused 100% mortality in newly hatched larvae of the bushfly, Musca vetustissima Walker (Diptera:Muscidae). In dung of day 35, mortality was 93.6%. Dung collected from sheep from 1–6 days after treatment also caused 100% mortality of fly larvae, but by day 28, no toxic effects were detectable. Field observations on the colonization of cattle pats confirmed the enhanced attractiveness of dung from treated animals and suggested that departure rates from treated dung were lower than those from untreated dung. Treated pats supported higher beetle populations than untreated pats and burial was more rapid. The potentially serious implications of the enhanced attractiveness of avermectincontaminated dung are discussed in relation to the survival of dung beetle communities.

In mixed cocoa-coconut palm plantations in Malaysia the palm spadices provide large, stable nesting sites for Dolichoderus thoracicus (Smith) in contrast to impermanent sites on cocoa and on the ground. D. thoracicus and the arboreal leaf-nesting Oecophylla smaragdina (Fabricius) both benefit from the mixed system which also provides a more stable food supply from honeydew-producing Homoptera. A scoring method showed that about 50–200 O. smaragdina or 200–2000 D. thoracicus on a cocoa tree can protect it effectively from Helopeltis theobromae Miller (Hemiptera: Miridae). The relatively greater efficiency of O. smaragdina as a biological control agent is associated with its actively dispersive predatory behaviour in contrast to the localized concentration of D. thoracicus workers at sites such as cocoa pods where it tends honeydew-producing Homoptera, and where it acts largely by deterring H. theobromae. Despite its biological control potential, the painfully biting O. smaragdina, unlike D. thoracicus, is normally considered unacceptable to plantation staff. Nevertheless it should be recognized as valuable in integrated pest management of cocoa pests especially where D. thoracicus is difficult to establish.

Targets of black cloth with or without flanking netting panels (ca. 1 m tall × 1.7 m) baited with acetone (130 mg/h) and 1-octen-3-ol (0.5 mg/h), coated with deltamethrin suspension concentrate and deployed at 4/km2, produced a decline of 3% per day in the apparent density of the tsetse fly Glossina morsitans centralis Machado in 500 km2 of the Western Province of Zambia. Flies were eradicated in a year as evidenced by the absence of catches from flyrounds and traps and the elimination of the transmission of trypanosomiasis. The promise of the target technique is confirmed but the need for its further development is emphasized.