The biology and ecology of Bradyrrhoa gilveolella (Treitschke), recently introduced into Australia as a possible biological control agent for the composite Chondrilla juncea, is described for Greece and compared with its known biology in southern Russia. The moth occurs from eastern Europe to southern Russia. In Greece it has two full and possibly a partial third generation each year. Its larvae live in cases below the soil surface and feed on the rootstocks of Chondrilla spp., destroying the thinnest plants. Heavy larval infestations on Chondrilla occur erratically in eastern Greece, being dependent on sites on sandy or very friable soils that are only occasionally disturbed; populations in hotter southern Greece appear to be less stable than those in the cooler northern regions. The larvae are heavily attacked by the fungus Beauveria bassiana as well as by Bracon sp., Copidosoma sp. and Syzeuctus sp. (Hymenoptera) and by the Tachinid Germaria graeca (Br. & Berg.); these cause a total larval and pupal mortality of up to 80%. Host specificity studies, during which the roots of various wild and cultivated composites and 62 cultivated plants were exposed to the moth larvae, showed that only Chondrilla and the closely related genus Taraxacum were attacked. A field survey showed that Taraxacum was not a host under natural conditions. All forms of C. juncea were equally readily attacked by B. gilveolella larvae.

Musca fergusoni J. & B. is an indigenous Australian fly that infests livestock, feeding on sweat and other body secretions and breeding in cow and horse dung. The fly is larviparous, developing a single larva at a time and depositing it at the end of the first instar. The ovaries comprise two ovarioles each, and the single ovulations alternate between ovaries and between ovarioles within an ovary. Abnormalities of development shown by unfertilised females are described, including the accumulation of fluid around unhatched eggs in the uterus which suggests that there is intrauterine secretion of nourishment for the larva. Descriptions are given of the immature stages. The egg is adapted for life in utero by having the respiratory plastron confined to the posterior end, oriented towards the genital aperture of the mother. The puparium is whitish, and is hardened by calcification instead of tanning. The durations of development at 16, 20, 27 and 32°C are given: from larval deposition to moult to third instar takes 58, 38, 19 and 15 h, respectively; from larval deposition to pupariation 11·5, 7·5, 3·5–4 and 3–3·5 days, respectively; and from larval deposition to adult emergence 53–57, 31–33, 15·5–16·5, and 10–11 days, respectively.

Samples of Aedes aegypti (L.) larvae were collected in domestic, peridomestic and feral habitats in the Rabai area, Kenya, and reared in the laboratory. Newly emerged mosquitoes, 2000 from each habitat, were marked with fluorescent pigments and released in a peridomestic habitat in Shauri Moyo village. Of the 407 mosquitoes recaptured in landing-biting collections on man inside houses, 83% were domestic, 15·5% were peridomestic and 1·5% were feral. These various recapture rates indicate the existence of three behaviourally distinct populations of A. aegypti: domestic, peridomestic and feral; they also indicate that the mosquitoes' ability to enter houses is a genetically controlled behavioural trait.

Two species of Gryon Haliday, parasites on eggs of blood-sucking Reduviids, are described, namely G. triatomae sp.n. from Singapore and India, reared from eggs of Triatoma rubrofasciata (De Geer) and Linshcosteus sp., and G. linshcostei sp.n. from India from eggs of Linshcosteus sp. The species differ in biological attributes but are not separable by morphology; with G. insularis (Ashmead) they form the insularis-group.

In crossing experiments with Gryon triatomae Masner, reared from the eggs of Triatoma rubrofasciata (De Geer) from Singapore and India, and G. linshcostei Masner, from eggs of Linshcosteus sp. from India, only the females of G. linshcostei yielded hybrids (3.9%). G. linshcostei accepted both hosts offered separately but preferred Linshcosteus when the two were provided together; G. triatomae showed poor acceptance of Linshcosteus eggs under both sets of conditions. In view of their reproductive isolation and these and other observed differences in their behaviour, these two sibling species could be selectively introduced into other areas for biological control of Triatominae.

A history of the changes in nomenclature within the genus Spodoptera is outlined. A key to the imagines of the eight species occurring in Africa and the Near East is presented, together with keys to the larvae and pupae of most of these species, including all those of economic importance in this region, as well as brief notes for identifying the eggs of six species. For each species, a separate account is given of its taxonomic features and affinities, general world and more detailed African distribution, as well as host-plants, including those of economic importance, and its vernacular names. The subspecies Spodoptera leucophlebia malagasy Viette, recorded only from the Malagasy Republic, has been raised to full specific status, and should now be known as Spodoptera malagasy Viette, stat. n.

From field observations and laboratory rearings, the biology of Forcipomyia squamipennis I. & M. in cocoa plantations in Ghana was established as follows. Adult midges are found between buttresses of large shade trees, in crevices of decayed old logs, in hollow tree stumps and cocoa husk heaps. Swarming takes place at any time during the day in or around the resting place, while dispersal occurs in the early morning and in the late afternoon, the normal flight range being 5–6 m. The largest populations occur in the rainy season. Eggs are laid on moist decomposing wood, cocoa husks and other plant debris in batches of 40–90; the larvae hatch in 2–3 days and pupate after four moults, when about 12 days old; the pupal stage lasts 2–3 days. Adult females require liquid plant food for survival and oviposition, although the maturation of ova is independent of adult food intake or mating; unfertilised eggs do not develop. The maximum adult life span for both sexes is eight days in captivity. F. squamipennis undergoes at least 12 generations a year. Due to its abundance and continuous breeding in cocoa plantations, F. squamipennis is probably the most important Ceratopogonid cocoa pollinator in Ghana. Both sexes are efficient pollinators, but four times more males than females visit cocoa flowers.

The vertical distribution of mosquitoes was investigated at Keneba in The Gambia, using flight traps and suction traps set up over open ground. Flight traps were used to sample three levels, ground to 1·37 m, 1·45–2·82 m, and 2·90–4·27 m. Suction traps were mounted in two series of experiments at three levels, 0·68, 2·13 and 3·51 m, and in a third series at four levels, 0·91, 305, 6·10 and 9·15 m. Most species, including Anopheles melas Theo., A. squamosus Theo., Aedes punctothoracis (Theo.), the Culex decens group, C. tritaeniorhynchus Giles, Mansonia africana (Theo.) and M. uniformis (Theo.), were most common near the ground, with catches declining progressively with height. C. thalassius Theo. was frequent at all levels, although the largest catches were taken at 9·15 m. Only C. neavei Theo. and C. weschei Edw. were more common in the higher traps. Although larger catches of A. melas and C. tritaeniorhynchus were taken during moonless periods, the numbers of other species were unaffected by lunar phase. In general, the presence or absence of moonlight had little effect on vertical distribution. However, C. thalassius and the C. decens group were shown to be more attracted to flight traps in moonlight, and it is concluded that visual responses were involved. A limited series of four-level, human-bait catches, with the catchers stationed at the same heights as the suction traps of the third series, produced results similar to those of the suction trap collections.

The amino acids of the haemolymph proteins of female Glossina austeni Newst. have been analysed at selected times during the first two pregnancy cycles by automatic amino acid analysis. The most prominent amino acids were glutamate, aspartate, lysine and leucine, with these amino acids accounting for almost 50% of the total amino acid residues. The molar percentage of all 16 amino acids observed varied only slightly throughout the pregnancy cycles. The amino acids of the perchloric acid-precipitable fraction of the gut contents of third-instar larvae (considered to be equivalent to milk secretion) have also been analysed and differ considerably from the haemolymph proteins, with glutamate and phenylalanine particularly prominent. Because of their low content of aromatic amino acids, the haemolymph proteins are not regarded as an important store of these compounds.

Aedes (Ochlerotatus) fryeri (Theo.) was found developing in saline pools on the coastal margins of coral islands near Dar es Salaam, Tanzania. Females were autogenous in the first ovarian cycle and anautogenous in the second ovarian cycle. The existence of autogeny was confirmed by examination of females reared from field-collected pupae and of the age structure of the population of females landing and biting. All females receiving carbohydrate and most females receiving only water as adults exhibited autogeny; only parous females were caught attempting to take blood. Water-fed females (and to a lesser extent, carbohydrate-fed females) showed a high incidence of follicular regression in the first gonotrophic cycle. The possible adaptive significance of autogeny in A. fryeri is briefly discussed.

Thirty-five species of mosquitoes (10 782 adults) were caught in modified CDC light-traps during the 27-week rice cultivation cycle at Ahero, Kenya, in the period September 1972 to March 1973. Only 0·8% were blood-fed and 5·1% gravid, indicating that the traps were sampling newly emerged adults. During weeks 1–7, before rice seedlings were transplanted, catches were small, but increased markedly from then until harvest (week 20). Two groups of mosquito species were recognised: the first, including Mansonia uniformis (Theo.), M. africana (Theo.) and Mimomyia splendens Theo., bred throughout the rice cycle; the second, including Anopheles gambiae s.l., A. pharoensis Theo., A. ziemanni Grünb., Culex poicilipes (Theo.) and C. antennatus (Becker), were affected by water depth and height of the rice crop. The slurry of shallow muddy pools which follows transplanting stimulated intense breeding of A. gambiae and A. pharoensis. Once the young plants were established, reflooding of the fields and subsequent growth of water plants and algae favoured the breeding of A. ziemanni and C. poicilipes. Towards the end of the rice cycle large numbers of C. antennatus were caught. It is concluded that mosquito control by means of insecticides or by irrigation management would be possible.

Using the inverse square law, estimates can be made of the distances at which illumination from a light-trap is equal to that from background sources. From these distances an index of trap radius can be constructed which can be considered as a measure of trap potential. Between new moon and full moon trap radii vary, depending upon the times of the night at which the trap may be operating, in ratios from about 10:1 to 15:1. A comparable index of light-trap catches can be calculated which allows catches to be examined in relation to changing radius of the trap. Analysis of a series of catches in Uganda and Ghana shows that many species are more abundant than expected in periods of moonlight, particularly at and near full moon, the biggest difference between new moon and full moon being about 10:1 for Marasmia trapezalis (Gn.), whereas the Isoptera, Bostrychidae and Spodoptera triturata (Wlk.) are 3–4 times more frequent at full moon. The ratios between catch at new moon and catch at full moon suggest that the primary determinant of catch is the frequency with which insects cross the boundary of a region of influence whose size is determined by a radius of equal energy. Deductions about the pattern of insect activity through a lunation, and nightly, and the general agreement between curves describing the change in radius of the trap and those of trap catches suggest that changes in catch over a lunation can be explained by changes in the effectiveness of the trap. When corrections are made to allow for such changes, all taxa show some increase in numbers in moonlit periods and in many taxa this increase is substantial. Correction of catches should take account of flight periodicity and this periodicity should, if possible, be confirmed by methods independent of light-traps.

A laboratory-reared British strain of Myzus persicae (Sulz.) did not readily accept the artificial diet that has been used to maintain North American strains. All components of this diet were re-tested in factorial tests and a modified diet was developed which contained increased amounts of alanine, leucine, phenylalanine, serine, folic acid, calcium pantothenate and pyridoxine, while omitting arginine, glutamic acid, histidine, tryptophan, valine, ascorbic acid, choline chloride, nicotinic acid and riboflavin. This diet, although less adequate nutritionally than the original diet, could maintain M. persicae for several weeks and more than two generations. It was readily accepted by aphids with few deaths in the first generation, so that it should be more suitable than the Californian diet for bioassay of systemic insecticides and for studies on substances that might influence aphid behaviour.