Bait containing 1% a.i. aldrin and used at a rate of 10 kg/ha gave good control of Anoplolepis longipes (Jerd.) in the Seychelles, especially when large areas were treated. Typically, 90% or more of the ants were killed, usually within the first few days. Depending on the area baited, population recovery took at least 3–12 months and was largely by re-invasion from untreated areas. The bait was relatively specific but chickens starved for 24 h would eat it when no other food was available. It is concluded that baiting is relatively inexpensive and provides a safe method of controlling infestations of A. longipes over large areas.

The third-stage larva of Oryctes monoceros (O1), a pest of coconut palms, collected in the Seychelles Islands is described and illustrated, and a key is provided to distinguish larvae of this species from those of O. boas (F.) and O. gigas Lap., all of which coexist in parts of Africa.

Catches of Glossina palpalis palpalis (R.-D.) and G. tachinoides Westw. at high and low densities with hand-nets, biconical traps and an electric back-pack trap in Nigeria indicate that both types of trap are inferior to hand catching for routine checks of G. palpalis and G. tachinoides populations. Hand catching is recommended as being most suitable for large-scale surveys, assessment of control following insecticide spraying and classical fly-rounds. The biconical trap is recommended for use in experiments of a limited size, monitoring of fly populations on livestock ranches and around Villages, and for capturing flies for dissection. The electric trap is recommended for use in sampling flies in areas of medium and high density and possibly for blood-meal identification. Some blood-meals of G. palpalis were identified.

The results are presented of a survey of the resistance to acaricides of strains of economically important ticks from the cattle-raising areas of Kenya in 1970–75. Larval progeny of ticks collected in the field were subjected to an immersion test to determine their resistance status to toxaphene and dioxathion. The proportions of samples of the three major species shown to be resistant to or tolerant of toxaphene were Boophilus decoloratus (Koch) 99·3%, Rhipicephalus evertsi evertsi Neum. 77·3% and R. appendiculatus Neum. 62·5 %. A large proportion of the relatively few samples of R. pulchellus (Gerst.) were also resistant to toxaphene, but few resistant samples of Amblyomma variegatum (F.) and Haemaphysalis leachii leachii (Aud.) were collected, and only one sample of Hyalomma (H. marginatum rufipes Koch) was tolerant of toxaphene. None of these species was resistant to dioxathion. Organophosphorus resistance was noted in one species only, R. sanguineus (Latr.), collected from the suburbs of Nairobi.

Moths migrating at Muguga, Kenya, were sampled at 24·5 m and 0·6 m above the ground by light-trap. The larger the species, the greater proportion of the sample it represented at the higher level. This effect was independent of family and morphological type. This result is important in considering the evolution of size with respect to orientation and migratory ambit and the role of downwind migration in population dynamics.

A study was made of the seasonal variation in population density of larvae of Boophilus microplus (Can.) in four locations in Jamaican pastures where the mean annual precipitation ranged from 59 to 222 cm. Variations in population density were related to rainfall. Generally, four months of heavy rains in August to November preceded significant increases in B. microplus populations in December to February. This was followed by a reduction then another slight increase, resulting in a bimodal pattern of activity. Although populations fell to very low levels by the end of the dry season, only in one focus were they depleted to undetectable levels.

Closely spaced stable traps were used to determine the preferences of mosquitoes for 6 vertebrates at Kowanyama, northern Queensland, on 4 occasions during the wet and dry seasons of 1974–75. A total of 44 626 mosquitoes from 35 taxa was collected and compared with 26 215 specimens of 15 taxa trapped at Charleville, south-west Queensland, in February 1976. Host preference was analysed in detail for 11 species; Anopheles bancroftii Giles, An. amictus Edw., An. annulipes Wlk., An. farauti Lav., An. meraukensis Venhuis, Aedes bancroftianus Edw., Ae. normanensis (Tayl.), Ae. vittiger (Skuse), Culex annidirostris Skuse, Cx. quinquefasciatus Say (=fatigans Wied.) and Mansonia uniformis (Theo.). All species in these experiments, including the important vector of arboviruses, Cx. annulirostris, preferred mammalian baits, especially calf, although An. bancroftii and Cx. quinquefasciatus preferred man. Blood-meals of 5802 engorged mosquitoes of 21 taxa collected from natural resting sites at Kowanyama village were analysed by the precipitin test. Mammals, particularly dogs, were the most important hosts. Cx. squamosus (Tayl.) and Cx. quinquefasciatus were the only species to feed extensively on birds (75–6 and 28–7%, respectively). Uranotaenia albescens Tayl. fed almost entirely on amphibia. No seasonal shifts in feeding of An. bancroftii, An. annulipes, Cx. annulirostris or Cx. quinquefasciatus were evident from either host-preference or host-feeding patterns, the latter being evaluated using a ‘ Feeding Index ’. These results are discussed in relation to the transmission of arboviruses, particularly Murray Valley encephalitis virus and pulmonary dirofilariasis of man and dogs in Australia.

As in previous limited entomological studies carried out toward the end of the 1969 yellow fever epidemic on the Jos Plateau, Nigeria, the vector mosquito was not identified, additional observations were made in April, June, August-September and October 1970. In the three study areas selected, each the scene of yellow fever cases in 1969, special attention was given to the larval habitats and adult biting cycles of five species of Aedes (Stegomyia). Holes in the broken or cut stems of Euphorbia kamerunica, a plant commonly used as hedge in rural settlements, proved to be well utilised by larvae of Ae. aegypti (L.), Ae. africanus (Theo.) and Ae. luteocephalus (Newst.), the latter species being the most abundant. Collections of adults on human bait, mainly from 12.00 to 21.00 h, showed that species of this subgenus comprised between 70 and 89% of all mosquitoes captured in June-October. Ae. luteocephalus always predominated, followed by Ae. aegypti, then Ae. vittatus (Big.), Ae. africanus and Ae. simpsoni (Theo.). Ae. aegypti was found not to be a domestic, household-inhabiting species in the study areas. The indications are that Ae. simpsoni is not strongly anthropophilic on the plateau. Two arboviruses, UgMP 359 and a member of the Bunyamwera group, were isolated, from Ae. (Aedimorphus) dentatus (Theo.) and Anopheles funestus Giles, respec tively; no isolations were made from 2033 adults of Stegomyia.

The biology of Aedes geniculatus (O1.) was studied in 1967–73 in Monks Wood National Nature Reserve, an oak-ash woodland, in southern England. Adult emergence from tree-holes occurred from May to September, and the sex ratio was approximately 1:1. Catches on man indicated that the maximum biting densities occurred in July and August and that females spend about two minutes obtaining a blood-meal. Significant positive correlations were found between their unfed weight and the weight of the blood-meal and also between female wing length and fecundity. The mean number of eggs per batch was 70. Studies with bamboo pots used as artificial oviposition sites in the field showed that the seasonal peak in oviposition spanned July and August, daily ovipositional activity was greatest in mid-afternoon and evening and ovipositing females preferred oviposition sites positioned within 4 m of the ground. A small proportion of eggs hatched during the summer in which they were laid, but most hatched in the following spring. Continuous or intermittent soaking failed to induce hatching until this time. In 'the laboratory, partially em'bryonated eggs required a minimum relative humidity of 88% to develop fully, but some embryonated eggs survived at 58%. Some eggs survived for 18–24 months in the field. The sampling of preadult stages dn tree-holes showed that larvae in the first two instars occurred almost throughout the year while third- and fourth-instar larvae were present in spring and summer. Pupae occurred only in the summer. It was concluded that A. geniculatus is univoltine in Monks Wood.

Many tomaspidine froghoppers are pests of crops in South America, and their current taxonomic position frequently does not reflect their true affinities. In this second revisionary contribution, certain generic features of Tiodus, Iphirhina, Tunaima and Urubaxia are described and compared, and 2 species are transferred to Maxantonia, 3 to Tunaima, 1 to Kanaima, 1 to Prosapia and 5 to Mahanarva. Huaina gen. n., Choconta gen. n. and Tiodus rufescens sp. n. are described. Monecphora fortunata Lall. is suppressed under Kanaima vittata (Wlk.), and Maxantonia scita (Wlk.) is recalled from synonymy with Monecphora quadrifasciata (Lep. & Serv.).

Anastatus umae sp. n., a parasite in the oothecae of two Indian species of cockroaches, mainly of Neostylopyga rhombifolia (Stoll), is described. It is assigned to Cladanastatus subgen. n. of Anastatus, based mainly on the branched antennae in the male and on some less conspicuous characters of the female. Eupelmus leithi Wlk., another Indian species, is transferred to Anastatus. In addition, two other parasites of Indian cockroaches, Tetrastichus hagenowii (Ratz.) and T. asthenogmus (Wtstn.), which were confused as a single species, T. hagenowii, in the synopsis of the cockroaches and their parasites by Roth & willis in 1960, are separated.

The overwintering of Heliothis armigera (Hb.) was studied in the Namoi Valley, north-western New South Wales, Australia. In field observations, over 80% of pupae formed during late April and May were found to be in diapause and did not resume development until September. Moth emergence from diapausing pupae occurred in a protracted period between September and November. Laboratory studies indicated the probability of two phases of diapause development, one completed under cool soil conditions of winter and a second requiring a temperature above about 17° C. The threshold of the second phase was higher than that for non-diapausing pupae and was not normally reached until late September. The times to diapause termination in populations of overwintering pupae were satisfactorily fitted to a geometric distribution, which was reflected in the protracted emergence period of moths in field cages. The limited availability of suitable host-plants for the overwintering generation and for emerging moths is discussed.

Spodoptera exempta (Wlk.) is predominantly a migrant species, but in southern Africa it is known that it can breed through several successive generations in one area. Similar observations were made for the first time in East Africa. Studies on populations in the Lambwe Valley in western Kenya revealed that during two years when the populations were monitored and one year when information was available from local farmers there were three generations each year during the period corresponding with the long rainy season. It is suggested that the Lambwe Valley presents a suitable habitat for the species to sustain its population and probably forms a breeding area for moths that might undergo large-scale migration.

The competitive abilities of seven calliphorid and one sarcophagid species were examined by investigation of various Characteristics of their larval growth curves. The relative success of each species is thought to depend to a great extent on the ability of the larvae to attain quickly the minimum weight for viable pupation. The ovoviviparous species (Calliphora nociva Hardy, C. augur (F.) and Parasarcophaga crassipalpis (Macq.)) were found to have the most rapid growth and Chrysomya megacephala (F.), Calliphora nociva and C. augur the highest assimilatory rate during the period of most rapid growth. Further, C. nociva, C. augur, Ch. megacephala and Ch. rufifacies (Macq.) were the species best adapted to pupation at low larval weight, which suggests that their food requirements for successful pupation were less (relative to maximum larval weight) than those of the other species. In this respect, Lucilia cuprina (Wied.) was also well–adapted and Ch. varipes (Macq.) was the least successful species.

The life-history of Dactylopius austrinus De Lotto on the weed Opuntia aurantiaca, is described. The male moults four times and the female twice. The instars are illustrated. Fecundity is shown to be a function of female density on the plant and of host-plant condition. The sexes were produced in a ratio of about two males to one female.

A laboratory colony of Stomoxys nigra Macq. was established in February 1976. Techniques were developed to produce 100 000 to 125 000 pupae daily in a larval room of 12 m2. The adults were fed on stored titrated blood and reared at a density of 500 pairs dn nylon cages with sides of 30 cm. The adult room was maintained at 29±1·5°C, 75–80 % RH and LD 14:10. To ensure a continuous supply of ovipositing individuals, 24 new cages with mature pupae were daily put in the adult room (capacity 280 cages) and an equal number of cages containing senile flies were removed. Eggs were harvested on moist khaki cloth below the adult cages, then concentrated in a trough of water and seeded at the rate of 1 ml (10 500 eggs) per kg of larval medium. The larval medium consisted of a mixture of 4 parts by weight of shredded sugar-cane (or elephant grass) leaves, 1 part soft Wheat bran and water at 2 ml/g dry matter. Larvae were reared in trays (45×35×7.5 cm) covered with cloth sacks to prevent invasion by pests. Eleven days after seeding, pupae were separated from the medium by flotation over water. From 2 September 1977 to 8 December 1977 forty trays, each yielding from 2000 to 3500 pupae, were harvested daily.

Catches of Glossina morsitans morsitans Westw. and G. pallidipes Aust. attracted to an odour-baited trap in riverine woodland in Rhodesia declined by about three-quarters over a 50-day period in the hot dry season. Concurrent catches from refuges suggested that the decline in trap catches was due to a reduction in population densities rather than a decreasing responsiveness of tsetse to the trap. Of G. pallidipes marked and released 250, 1250 and 2250 m from the trap, the percentages recaptured in the trap after 5 days were about 20, 10 and 4, respectively, and after 40 days about 28, 15 and 13. The sustained responsiveness to the trap and efficiency with which marked flies were removed suggested that odour-baited traps at an economical spacing of roughly one per 10 km2 could produce effective control of G. pallidipes.

The flight activity of adult Delia coarctata (Fall). was studied on Rothamsted Farm from 1969 to 1977 using light-traps. These catch, almost exclusively, dispersing mature females, more being caught at full moon than at new moon. Dispersal begins in response to an acceleration in the rate of decrease of daylength, and at Rothamsted begins on 10 July, soon after the rate of decrease accelerates. Maturation of eggs is controlled by temperature; at Rothamsted, the first mature females appear when temperature accumulation above 5° C has reached 314·5±10·5° after 12 June. Maturation usually coincides with dispersal, but females that have matured before 10 July do not disperse until after that date. Catches of females in light-traps are correlated with the numbers of emerging females per hectare and the numbers of eggs per hectare. Light-traps could be used as a simple way of forecasting numbers of eggs early enough to give advice on seed treatment for winter wheat on land subject to attack by D. coarctata.

In studies in southern England in 1967–77, the numbers of Lonchoptera lutea Panz. in cereal crops, such as winter wheat, fluctuated from year to year, depending on an adequate supply of food, provided by decaying litter, for the larvae and on sufficient rainfall to keep the soil surface moist during May and June. Much sunshine was unsuitable for larval growth. The larvae fed mainly on fungal spores and were able to breed in wheat litter in the laboratory. In years when many crop plants were attacked by shoot borers such as Delia coarctata (Fall.) and Oscinelta frit (L.), L. lutea was more numerous than when there were few. Although in most years more males than females appeared in emergence traps, more females than males were caught by sweeping and in light- and suction traps.