Observations were made on the bionomics of Spodoptera mauritia acronyctoides Gn. in Malaysian Borneo (Sarawak) during an outbreak in 1967. The outbreak was discontinuous over about 6 000 sq. miles, affecting 25 000 acres of lowland and upland rice. In the insectary the durations of the various stages were: egg 2·9 days, first- to seventh-instar larvae respectively 3·1, 1·8, 2·2, 2·1, 2·2, 2·3 and 4·9 days, and pupa 8·4 days. Larval instars could usually be distinguished on head width and the width of the faecal pellets. Food consumption of the larvae was greatest during the final instar. During the outbreak the larvae were found mainly on young rice, and also on young maize; wild host-plants included grasses and sedges, but dicotyledonous plants were not attacked.

Females generally mated on the night following emergence, and the pre-oviposition period averaged 2·9 days. Fertilised females laid an average of 1 749 eggs, 80% of the potential total. Virgin females laid only 22% of the potential, and resorbed some of their oocytes. The mean longevity of fertilised females was 5·5 days. Fecundity was directly correlated with pupal weight or length, and the weights of pupae produced in wet-rice fields were significantly heavier than those from dry hill-rice sites. There was a significant correlation between the weight of frass produced (hence food consumed) by the seventh-instar larva and the weight of the pupal stage. Pupae from larvae in crowded cultures were significantly lighter than those reared singly.

The larvae of three species of bark beetle, Scolytus scolytus (F.), S. multistriatus (Marsham) and Pteleobius vittatus(F.) are described and figured. The larva of S. scolytus resembles most closely that of S. triarmatus (Eggers) but the species appear to be distinct. The larva of S. multistriatus is clearly separated from all other Scolytus larvae so far described. The larva of P. vittatus is most closely related to those of the genera Hylesinus and Leperisinus. The characters of the larvae largely support classifications based on adult morphology and anatomy.

Individuals of Glossina pallidipes Aust. were reared separately on five developmental categories of guinea-pigs (infants, suckling mothers, pregnant females, mature virgin females, and mature males), from the time of adult emergence until they died, at 22±1°C and 40±5%r.h. More than 70% of the tsetse flies reared on infant guinea-pigs or on suckling mothers died within the first 10 days, before they reached sexual maturity. Of those reared on mature male guinea-pigs, 50% lived for more than 50 days.

Pregnant female and mature male guinea-pigs were the most favoured hosts for tsetse feeding: more than 90% of the flies exposed to these two classes of hosts succeeded in feeding, while only 61%, 70%, and 76%, respectively, of those exposed to infants, suckling mothers, and mature virgin females actually fed.

The puparia of some Cyclorrhaphous Diptera resemble and are found among those of tsetse flies (Glossina spp.). Those of Plesiocyptera sp., Argyrophylax aureiventris (Villen.) (Tachinidae) and? Physocephala (Conopidae), are described and illustrated, as are the larval cephalopharyngeal skeletons recovered from the puparia.

Ecological studies were undertaken from 1964 to 1966 on the mosquitoes that occurred in the Poole area of Dorset, southern England. The seasonal incidence was obtained of adults of Aedes cinereus Mg., Ae. punctor (Kby.), Ae. cantans (Mg.), Ae. detritus (Hal.), Culiseta annulata (Schr.), Mansonia richiardii (Fic.) and Anopheles plumbeus Steph. There were marked annual variations in their populations. With the exceptions of Ae. cinereus and Ae. cantans, their diel biting cycles were obtained. In most species maximum biting occurred around sunset and sunrise, with a reduction in biting at night. A comparison was made of the biting times of Ae. detritus and M. richiardii at sunset and sunrise in July and August. By dividing the catch into five-minute intervals peak biting times were related to crep values.

The daily oviposition rhythm of the tea red spider mite, Oligonychus coffeae (Nietn.) under laboratory and field conditions is described. In the laboratory, the oviposition rate was steady under constant light or darkness, but under alternating light and darkness (LD 12:12 and 8:16) showed peaks soon after the change from light to darkness and vice versa. Under field conditions, oviposition peaks occurred at dawn and at dusk when there is a rapid change in light intensity.

Anastatus sp. (Eupelmidae) is recorded for the first time parasitising a puparium of Glossina palpalis (R.-D.) in West Africa. Hitherto, the only records of Eupelmids parasitising tsetse flies have been of A. viridiceps Wtstn. and Eupelmella tarsata (Wtstn.) from G. morsitans Westw. in eastern and southern Africa. The parasite emerged through a large hole anterior to the polypneustic lobes. Parasitic Eupelmids do not normally utilise tsetse flies as hosts.

An apparatus for dispensing the eggs of cabbage root fly (Erioischia brassicae (Bch.)) is described. It consists of an ‘Agla’ micrometer syringe, a 2-ml pipette and a 20-mlsyringe connected together by a three-way valve. The eggs are dispensed volumetrically, the standard errors being < ±10% for batches ranging from 30 to 300 eggs. This degree of variation had no measurable effects on the uniformity of pupae from cabbage root fly cultures.

Laboratory studies were conducted on the incubation period of the desert locust, Schistocerca gregaria (Forsk.). When egg-pods were incubated at constant temperature, the duration of the incubation period ranged from 50 days at 19·7°C to 11–12 days at 35–41 °C. The colour of the resulting hatchlings showed dependence on temperature, ranging from grey-white at 41 °C to overall black at 20°C. The minimum temperature at which embryonic development took place was 15·1°C, while the minimum temperature for the hatching sequence was about 20–24°C. The upper lethal limit for embryonic development depended both on temperature and on the duration of exposure of the eggs to that temperature. For example, constant temperatures above 38°C throughout development reduced viability, but exposure to 40°C for six hours each day did not adversely affect development or hatching. Between 15·1 and 35°C the rate of egg development was proportional to temperature; above 35°C the rate appeared to be constant and independent of temperature. Embryonic development was complete when the eggs had experienced 224 degree-days above 15·1°C, except at temperatures in excess of 35°C.

A laboratory technique is described which enables large numbers of Simulium larvae from field sources to be established in a narrow 12-in. long experimental channel in the laboratory where they can be maintained in a continuous flow of water. The apparatus was primarily designed for a critical study of the reactions of larvae exposed to various time/concentrations of larvicides and other chemicals. By exposing dense aggregations of many hundred larvae at a time, significant figures can be obtained regarding the number of larvae detached at various intervals during and after exposure to larvicide, and also regarding the subsequent survival or mortality of the different detached fractions.

Natality is more important than mortality in the determination of the number of first-generation adults of Scolytus scolytus (F.) to emerge. The reverse is the case for the overwintering generation. Temperature is a probable key factor for the first generation, and subcortical predators for the overwintering generation. These results are related to possible control of the beetle as a vector of Dutch elm disease by injection of systemic insecticides. It is suggested that control measures may only be necessary in the climatic conditions of the United Kingdom in hot summers when a large first generation is likely to emerge. Natural mortality factors will effectively reduce the beetle population that overwinters.

Examination of infested bean plants (Phaseolus vulgaris) showed that “bean fly” in East Africa consists of three species, Melanagromyza phaseoli (Tryon), M. spencerella sp. n. and Ophiomyia centrosematis (de Meij.). M. spencerella is described, and notes are given on the life-cycle, host-plants and distribution for all three species. Their importance in East Africa is discussed and it is concluded that M. spencerella is the most damaging because it oviposits and feeds in the hypocotyl, is frequently the most abundant species and is less effectively parasitised. Bean plants able to produce adventitious roots freely are able to grow away from the important early attack in the stems. Published work on chemical control measures is summarised.

The parasite complex associated with bean fly in East Africa was studied, and notes are given on the species present, the recognition of their early stages, their host ranges and abundance. Parasitism is discussed in relation to the infestations found on beans, with special reference to Opius melanagromyzae Fisch., the most important parasite of M. phaseoli, and Eucoilidea sp., the most important parasite of M. spencerella. It is concluded from graphical analysis that O. melanagromyzae is density-dependent and an important factor in limiting M. phaseoli populations in East Africa. Eucoilidea sp., on the other hand, shows signs of delayed density-dependence and is less effective in controlling its principal host. O. melanagromyzae has recently been sent to Hawaii for release against M. phaseoli; some field recoveries have been made already.