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.

A total of 56 species of Scolytidae and four species of Platypodidae, 25 of which are endemic, is recorded from Samoa (American and Western Samoa). The nomenclature of earlier species records is brought up to date and the following changes are made: Xyleborus torquatus Eichhoff=X. silvestris Beeson syn. n.; X. wilderi Beeson=X. upoluensis Schedl syn. n.; Eccoptopterus eccoptopterus (Schedl) comb. n. (from Xyleborus). Brief notes are given of the distribution, biology and host trees of each species, with special reference to 41 species found in a survey of the island of Upolu (Western Samoa). Species causing damage were Crossotarsus externedentatus (Fairmaire) found attacking living Eucalyptus trees, and Hypothenemus birmanus (Eichhoff), involved in the death of some mango transplants. Eighteen species of potential economic importance in relation to Samoan crop and timber trees are divided into four groups: potential pests of seedlings and transplants; of established living trees as twig borers; of living trees as primary timber borers; of felled logs and unseasoned sawn timber.

The size and occurrence of the first brood of adults of Aeneolamia varia saccharina (Dist.) are examined in relation to the pattern of egg eclosion and rainfall. The proportion of eggs hatching within a month of oviposition in the laboratory (short-period eggs) decreased from over 90% in August to less than 20% in January, but the incubation periods of the remaining, long-period eggs were longest in those laid during October and November. The overall hatching distributions tended to be bimodal with most eggs hatching during the early months of the year under moist conditions at 26°C. Dry soil conditions delay eclosion, and eggs obtained from fields during the dry season and then incubated under moist conditions tended to hatch at the normally expected time of the first rains in May. The numbers of eggs expected to produce the first brood, computed from laboratory hatching data and estimates of the numbers and fecundities of froghoppers during the second, third and fourth broods, were less than the actual numbers sampled just before the first rains. There was a close relationship between the first rainfall of over one inch within 48 h and adult emergence 27 and 34 days later, and 85% of field egg populations in May had hatched and/or died by the week after the first rains. However some variation in the date of their occurrence accounted for non-synchrony of first broods over the region. The numbers of diapause eggs in fields sampled during the dry season failed to give a good predictive relationship with first brood adult populations, probably because of density dependent mortality of eggs or hatchling nymphs.

Single-species and mixed-species populations of Tribolium castaneum (Hbst.) and T. confusum Duv. were followed in two experiments. Food (flour) was renewed at various intervals between 30 days and 180 days or was not renewed at all. As the interval between food renewals lengthened, single-species populations of T. confusum became extinct later than populations of T. castaneum, the survivor in mixed-species populations changed from T. castaneum to T. confusum, and the mixed-species populations became extinct later than the single-species populations. When resource is limited, therefore, populations of the two species may persist longer if they compete than if they are husbanded as single species.

One gynandromorph and six intersexes of Austrosimulium bancrofti (Tayl.) are described from specimens caught in Queensland. All of the intersexes, as well as some normal flies, were infected with mermithid larvae. The infected flies rest preferentially on trees near the river's edge which would facilitate deposition of mermithids in the river. Except for a few with mature eggs, infected females had little internal abdominal structure, and most lacked ovaries.

Singapora diversa sp.n. is described from specimens found breeding on Pterocarpus macrocarpus in Thailand, and a key is given to the four known species.

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.

Adult males of Locusta migratoria migratorioides (R. & F.) had an oxygen consumption of 120 mm3 g-1 h-1 at 15°C and 988 mm3 g-1 h-1 at 37°C, although respiratory quotient in fed insects (0.83) did not alter over this temperature range. Starvation or starvation and desiccation reduced the respiratory quotient from 0.83 to 0.77 indicating a shift in metabolism from carbohydrates towards fats. It is shown that the amount of biologically useful energy produced (in the form of ATP) remains the same, and that a shift from carbohydrate to fat metabolism requires the depletion of a smaller weight of food reserve. The shift is counterproductive in terms of metabolic water production, as only 0.28 mg g-1 h-1 water is produced in starved or desiccated locusts compared with 0.35 mg g-1 h-1 in fed animals.

The carob gall midge, previously known as Eumarchalia gennadii (Marchal), is formally assigned to Asphondylia H. Loew, and Eumarchalia Del Guercio is synonymised with Asphondylia. Specimens of Asphondylia reared from pod galls on carob (Ceratonia siliqua) during biological research by G. M. Orphanides in Cyprus seem to be morphologically indistinguishable from specimens reared by him from galls on Capsicum annuum, Capparis spinosa, Urginea maritima, Asphodelus fistulosus, Solanum tuberosum, Hypericum crispum and Sinapis spp. Possible reasons for this unusually wide host range of the carob midge are discussed with particular reference to the occurrence of ambrosia fungi in galls of the genus Asphondylia. Gall midges reared from Verbascum sinuatum in Cyprus are morphologically distinct from A. gennadii and are identified as A. verbasci (Vallot). Characters separating these two species are illustrated and tabulated.

Hylurdrectonus araucariae Schedl is a major pest in hoop pine (Araucaria cunninghamii) plantations at Bulolo and Wau in Papua New Guinea, establishing itself in nests inside the branchlets. The length of the excavation is proportional to the age of the nest. Colour changes in infested branchlets reflect changes in colony composition and in excavation activity as the colony ages; the branchlet eventually dies and falls off and severely infested trees lose much of their foliage. Data from field observations between 1967 and 1972 show that there are 5–10 overlapping generations of H. araucariae in a year. The life-cycle takes place wholly within the branchlet, except for a brief period of flight or walking by the adult when seeking new nesting sites. The eggs incubate for 5–15 days, larvae take 10–25 days, pupae 10–15 days, and the immature adult 2–10 days; the adult may live 60 days or more. The colony composition is fairly stable in heavily infested areas throughout the year, except during drought. Colony composition and size vary from branchlet to branchlet or from tree to tree, but are more similar on trees with a similar stage of infestation. No significant natural enemies were found.

The direction of mosquito flight near the ground, in relation to wind direction, was investigated at Keneba in The Gambia, West Africa. Directional flight traps facing eight directions sampled mosquitoes flying between ground level and 1·4 m, and unbaited and baited catches with a calf at the centre of the trap circle were performed. Data on non-host-oriented flight were obtained for unfed female Anopheles melas (Theo.), Culex thalassius Theo. and C. tritaeniorhynchus Giles from the unbaited catches, and from all catches of unfed females of the C. deceits group, and gravid and male mosquitoes, which did not respond to the calf. The baited catches included large numbers of A. melas, C. thalassius and C. tritaeniorhynchus, and fewer Anopheles squamosus Theo. and A. ziemanni Grünb. In both unbaited and baited situations, flight appeared to be in a predominantly upwind direction, although mere was some indication, in the presence of a calf, of convergence into the host stream.

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.

In laboratory colonies of Atta cephalotes (L.) and Acromyrmex octospinosus (Reich) pick-up responses to paper discs impregnated with arrestant and inhibitory solutions and feeding responses to measured amounts of these solutions were progressively increased by increasing the concentration of arrestants and decreasing the concentration of inhibitor; the inhibitor had a much greater effect on feeding than on pick-up. Both species picked up paper discs impregnated with arrestants and Acromyrmex readily incorporated these into the fungus garden, while Atta did this less readily. Foraging of arrestive paper discs presented regularly for several days was maintained by Acromyrmex but declined in Atta. Both species were less selective during periods of high foraging activity and during a shortage of suitable substrate. Incoming foragers did not seem to influence the preferences of the outgoing ants, but different colonies showed different preferences. Initially little preference was shown for new materials but on subsequent encounters widely fluctuating preferences emerged, which stabilised within two weeks. Over longer time periods further changes in preferences occurred. The ants' pick-up, cutting or feeding response to a particular material is determined by its chemical and physical nature, the amount of chemical information which the ants obtain, and the threshold of their response. This threshold is modified by such factors as the genetic composition of the colony, the previous quantitative and qualitative availability of the substrate, and the general level of foraging activity. Practical implications of these findings for toxic bait production are discussed.

The preparation and use of a simple, durable silicone membrane for feeding females of Glossina morsitans Westw. are described. Mean fecundity and mean pupal weight were nearly as good on the silicone membrane as on agar/Parafilm or rabbit ears, and survival of females after 108 days was 46·7%, as against 4·4% and 24·7%, respectively.

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 Cyprus, the pods of the carob tree (Ceratonia siliqua) are infested by three races or sibling species of midges: the pepper, caper and squill midge (Asphondylia spp.). This classification has been made on the basis of secondary host-plant preferences. Tests in cages revealed that secondary host-plants which are attacked by these midges during spring, summer and autumn, taken together, are: pepper (Capsicum annuum), potato (Solanum tuberosum), caper (Capparis spinosa), garden rocket (Eruca sativa), mustard (Sinapis spp.), sea squill (Urginea maritima), asphodel (Asphodelus fistulosus), and St Johnswort (Hypericum crispum). The carob midge complex overwinters as young larvae in carob pods and may have a maximum of six or seven generations per year according to the location. The emergence pattern of the overwintering generation varied between locations. The adult sex ratio was 42 ♂ : 100 ♀ and the mean longevity under laboratory conditions was 55 h. Some major morphological characteristics of all developmental stages are also presented. The larval stage is divided into three instars. Sex identification has been determined at the pupal stage.

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 key is given to the larval instars, of which there may be nine or more, of Inopus rubriceps (Macq.) and I. flavus (James); the key is based on setal characters and development of the cranial lobes. Characters allowing recognition and sexing of the pupae are also described.

A description is given of a simple moveable platform which enables workers using stereoscopic microscopes to focus their work accurately without the need to remove their hands from the specimen or work area.

Counts of first-instar larvae showed that in a potato plot near Canberra, A.C.T., eggs of Phthorimaea operculella (Zell.) were more prevalent around the bases of plants than between the rows or 2 m outside the plot; the few eggs on the plants were on dead leaves. In small plots each of different plant species, with due allowance for predation, many eggs were laid around tobacco and potato, and few or none near tomato, maize, lettuce or pea. Older larvae were most numerous on tobacco plants, while adults were most numerous on potato plants. A series of laboratory experiments using different oviposition substrates showed that the factors favouring oviposition could be ranked, in descending order: coarse substrate, shade, and treatment of the substrate with juices of potato tubers or foliage; foliage of potato or tobacco was not preferred.