Termite damage is a major problem in tropical forestry especially where exotic tree species are used. Stressed tress are generally the most susceptible to attack. Dry-wood termites (Kalotermitidae) live and feed in dead wood but sometimes attack living parts of mature trees; generally, they are pests only in the humid tropics, causing local but sometimes serious damage. Coptotermes (Rhinotermitidae) causes more widespread and serious damage to mature trees, especially in Malaysia and Australia. The most serious losses (up to 100%), due predominantly to various Macrotermitinae (Termitidae) such as Macrotermes, Odontotermes and Microtermes, occur in young, exotictrees such as Eucalyptus in dry regions in Africa and India. Chemical control of dry-wood termites is not feasible; use of resistant trees is probably the only satisfactory strategy. Control of Coptotermes by various methods has been suggested; but only insecticide injection into nests within affected trunks (Australia) and destruction of nests with explosives prior to planting, followed by destruction of queens in subsequently located nests (Papua New Guinea), are effective and economically viable. Attack on seedings, especially by Macrotermitinae in Africa and India, can be prevented by the increasingly unacceptable persistent cyclodienes used as mound poisons or as a barrier around the roots preventing attack by subterranean species. Controlled-release formulations of otherwise non-persistent insecticides are being development but are expensive and not widely available. Many non-chemical measures have been suggested, but none has been rigorously evaluated; none will provide the almost complete protection afforded by cyclodienes. Biological control shows little promise. Use of resistant tree species and development of resistant varieties offers the only long-term solution, but until these are available there will be a need to continue using cyclodienes or rapidly to develop alternative control methods.

A Robinson 125-W mercury-vapour light-trap was operated at an exposed site near Cranfield aerodrome, south-eastern England. The effects of moon-light, temperature and wind speed on light-trap catch were investigated. The dependent variable, In (catch +1), was compared with the independent variables moonlight illuminance, air temperature and wind speed, using multiple regression analysis. An algorithm was developed and used to estimate moonlight illuminance. Increases in mean illuminance and mean wind speed were associated with a decreased light-trap catch. Increases in mean temperature were associated with an increased catch. When the moth catch was broken down into individual families and species, other trends became apparent. Catches of noctuid moths were unaffected by variation in mean illuminance, although they were influenced by variation in mean temperature and mean wind speed. On the other hand, catches of crambine moths were very sensitive to fluctuations in mean illuminance and mean wind speed although unaffected by changes in mean temperature. The multiple regression equations were used to predict future light-trap catches. The correlations between observed and predicted In (catch +1) for (a) all moths, (b) noctuid moths and (c) crambine moths, were very good. It is suggested that the observed moonlight trend for crambine moths is a consequence of changing behaviour as moonlight illuminance changes rather than the alternative of changing light-trap effectiveness.

A strain of Anopheles culicifaciesGiles (species B) originally collected from Aurangabad, Maharashtra State, India, showed highly specific resistance to malathion. Homogenates of one-day-old adults metabolized 14C-labelled malathion at a level comparable with strains of A. stephensi Liston and A. arabiensis Patton known to possess the malathion carboxylesterase resistance mechanism and at a higher rate (6.4 and 7.8 times, respectively) than malathion-susceptible strains of these species. The major metabolite obtained was malathion dicarboxylic acid, a carboxylesterase product, which suggests that this may be the principal resistance mechanism in this strain. Levels of non-specific esterase activity in larvae and adults were similar to those shown by both the susceptible and resistant strains of A. stephensi, implying that no quantitative increase in esterases had occurred. Microtitre plate assays on individual mosquitoes provided no evidence for the presence of the insensitive acetylcholinesterase resistance mechanism.

Bruchus dentipes Baudi was found to have four larval instars, and the sex ratio was very close to 1:1. Both sexes fed on pollen and nectar of faba beans (Vicia faba) for seven days before and throughout the oviposition period of the females, which was about 33 (range 26–40) days. The beginning and peak of oviposition were influenced by the phenology of the crop, particularly flowering and pod-setting dates, but also temperature. Females laid an average of 123 (range 28–310) eggs, and the end of the adult life in the field came in May when the pods had matured. In different years, peak oviposition occurred on different dates in April when the pods were still all green. During the quiescence period in the winter, females obtained from wetted seeds were fed with different diets in the laboratory, but only those supplied with faba bean flowers laid eggs. No major adult mortality occurred in seeds harvested in May and stored until the end of March of the following year, after which mortality rose steeply till all adults had died by early June. Therefore, storing seeds and delaying their planting till the following year will ensure 100% adult mortality. As the seeds remain viable, such storage is one method for reducing infestation in the field. Mortality of larvae in the stored seeds was from cannibalism when two larvae met at the same tunnel (10%), from the mite Pyemotes tritici (Lagrèze-Fossat & Montagné) (11%), from the braconid larval parasite Triaspis thoracicus (Curtis) (2%) and from unknown reasons (5%).

Field screening experiments for resistance of faba bean (Vicia faba) to Bruchus dentipes Baudi in Syria between 1982 and 1985 involved about 1000 accessions and indicated that only phenological resistance was present. Two accessions were chosen, on the basis of seed infestation with larvae, for further study. The two accessions (BPL33 and ILB1814) were tested against natural infestations as well as under four levels of bruchid infestation and at two different times of release of adults. BPL 33 maintained its resistance (about 50%) in relation to ILB1814 under these different conditions, except when adults were released at a time when both accessions carried pods simultaneously. This confirms that the resistance of BPL33 was phenological, related to late flowering and late pod setting. An intergrated control approach is there fore suggested.

A study was made of ants in Sri Lankan coconut plantations, especially of species foraging and nesting in palm crowns. At least 11 species were found nesting in the spadices, and a special study was made of interactions between some likely to be insect egg predators or to interfere with predation. Oecophylla smaragdina (F.) and Paratrechina longicornis (Latreille) were mutually exclusive, but some non-dominant species such as Monomorium spp. commonly nested and foraged in palms occupied by large populations of dominants such as O. smaragdina and Crematogaster sp. Eggs of the coconut pest Opisina arenosella Walker (and of Corcyra cephalonica (Stainton), which were used to simulate the former on palm fronds) were rapidly found and removed by certain ant species, notably M. floricola (Jerdan) and Crematogaster sp. Oecophylla smaragdina and P. longicornis seemed erratic as egg predators. Surveys of ants in areas where Opisina arenosella does, and does not, develop to outbreak populations showed that Monomorium spp. in particular were notably more common in the non-outbreak areas. However, other ants, notably Technomyrmex albipes (F. Smith), were sometimes common in outbreak areas and were seemingly good egg predators. The presence of thriving Oecophylla smaragdina colonies on currently attacked palms shows that this otherwise well-recognized predator has little or no effect on Opisina arenosella. It is concluded that several species of ants which nest in coconut palm crowns probably contribute importantly to the mortality of eggs of O. arenosella and help keep it in its rare endemic state in most places most of the time, even in outbreak areas.

A presence-absence sampling procedure is presented which relates the proportion of leaves infested with the mite Mononychellus tanajoa (Bondar) at a given node of cassava to the mean number of mites per leaf at that node. The procedure incorporates Taylor's variance-mean density relationship, taking into account mite aggregation behaviour. Aggregation of M. tanajoa was greater in plants where mite predators were excluded, on a resistant (CG5-79) rather than a susceptible cassava clone (MCol 22) and on leaves arising from the lower nodes rather than the higher ones. The implications of the effect of mite mortality factors on aggregation are discussed.

The within-row dispersion characteristics of larvae of Antitrogus mussoni (Blackburn), A. parvulus Britton, Lepidiota crinita Brenske, L. negatoria Blackburn, L. noxia Britton and L. picticollis Lea in sugarcane were determined in studies in southern Queensland, Australia. The Poisson distribution, negative binomial distribution, Iwao's regression model and Taylor's power law analysis were used to determine the relationship between mean and variance of larval counts. All methods examined showed that the larvae were slightly aggregated. Taylor's power law generally gave equivalent or better fits to the population dispersion compared with the other models. The power law relationship for L. picticollis differed from those of the other five species, and a common relationship for those five species was determined. Relationships to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling were developed for both L. picticollis and the other five species. There were functional relationships between the variance and mean of untransformed population counts for all species, and the suitability of transformation functions is discussed.

Triks of the group of Rhipicephalus sanguineus (Latreille) in 423 total monthly collections taken from camels, cattle, donkeys, sheep and goats between September 1978 and August 1979, and in a few miscellaneous collections, from the Yemen Arab Republic were examined. Adult ticks of three species in the group were identified: R. camicasi Morel, Mouchet & Rodhain, R. turanicus Pomerantsev and R. sanguineus s.s. Host relationships and ecological affinities were analysed. R. sanguineus s.s. occurred rarely, only on dogs. R. turanicus occurred on all host species including dogs but more frequently on cattle and camels. It was collected from both dry and wet habitats but was taken regularly at only one wetter site. R. camicasi, the most common species in the group, occurred at most collecting sites on all host species except dogs. Overall, the numbers of R. sanguineus group ticks were low throughout the country and no seasonal patterns could be detected.

Experiments were conducted in a cotton field in north-western New South Wales to determine the effect of pheromone trap design and placement on the catch of Helicoverpa punctigera (Wallengren) and H. armigera (Hübner) adults in paired traps. A cone trap design was found to give consistently larger catches of moths than two funnel trap designs. Furthermore, lower efficiency of catch of H. punctigera tended to bias relative catches in the funnel traps towards H. armigera. In comparison to the ratios of the two species in egg samples from the field, the cone trap did not show much bias to either species of moth. Traps located 40 m inside a cotton field showed larger catches and reduced variation compared with egg species ratios than traps placed at the edge of the field. Wind speed and direction and insecticide application also affected the catch in the traps. The catch data tended to become unreliable after the end of February, possibly due to changes in crop attractiveness for oviposition. It was found that the less numerous moth species at a given time still tended to be over-represented in pheromone traps in comparison to the ratios in egg counts. A linear time trend was introduced to compensate for the bias. The use of the traps shows promise in determining the relative abundance of the two species for use in resistance management strategies and other purposes.

A procedure for rearing Clavigralla tomentosicollis Stål on dry seeds of cowpea (Vigna unguiculata) is described. Dry seeds produced results for nymphal development and adult oviposition similar to those from fresh pods and fresh seeds, which are more frequently fed on by the insect in nature. The rearing method described here is much more efficient in terms of time and manpower requirements than the widely used method using fresh pods. Furthermore, the dry-seed procedure may be adapted for rearing other hemipteran pod pests of legumes.

Apanteles agonoxenae Fullaway and A. orelia Nixon are founded to be conspecific. The valid name for this species is, A. agonoxenae and A. orelia is a junior synonym of it. The species, which is a parasite on the coconut pest Agonoxea argaula Meyrick in the south-western Pacific, is redescribed, its distribution and biology are summarized and attention is drawn to its potential as a biological control agent.

The taro-feeding delphacid genus Tarophagus is revised. Three species are recognized: T. colocasiae (Matsumura) stat. rev. & comb. n. with which T. proserpina taiwanensis Wilson is synonymized; T. persephone (Kirkaldy) with which T. proserpinoides (Muir) and T. proserpina australis Fennah are synonymized; and T. prosperpina (Kirkaldy). The three species are separated by characters of the male and female genitalia, and each has a different distribution in Asia and the Pacific. Only in Papua New Guinea are all three species sympatric. Earlier studies on biology and pest status are reviewed in the light of these investigations.

Pieces of netting and sheeting of various types were impregnated by dipping them in permethrin emulsion. Bioassays were performed in which three species of mosquitoes were exposed to the impregnated fabrics for periods of between 15 s and 8 min. When pieces of netting and sheeting were dipped in permethrin emulsion at ambient temperature, the amount of insecticide absorbed was generally proportional to the weight of liquid taken up, i.e. there was no evidence of selective absorption. Diffusion of permethrin did not occur between pieces of netting and sheeting sewn together. The LD50 on cotton nets was found to be about three times as great as on nylon nets. Aedes aegypti (L.) was found to be more susceptible than Anopheles gambiae Giles, which was more susceptible than Culex quinquefasciatus Say. Although for most other groups of insecticides variation in time and dose have equivalent effects, for permethrin on netting this was not found to be true, i.e. on having the exposure time the LD50 was less than doubled.

The feeding responses, growth and population development of Nilaparvata lugens (Stål) are quantified on a range of twelve susceptible or resistant host-plants. Paris of rice varieties carrying the Bph1, bph2 and Bph3 resistance genes are compared as hosts for N. lugens, and it is concluded that such notations do not adequately describe the diversity of plant resistance mechanisms. Evidence is presented for resistance mechanisms involving enhanced insect activity and gustatory responses to unacceptable phloem.

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.