On the basis of specimens from New Guinea and New Britain, the genus Dynamenais Kirkaldy (Pyrrhocoridae) is re-defined, four species and one subspecies are described in the new subgenus Syncrotus (Syncrotellus) (Pyrrhocoridae), and two species are described for the new genus Goilalaka (Pentatomidae). S. (S.) similis sp.n. was recorded from cacao, and S. (S.) madanganus sp.n. and G. rubroruga sp.n. from Solanum spp.

Three new species and one new genus of Eulophidae are described, namely, Wichmannia pictipennis sp.n., reared from small bark beetles living in Euphorbia in the Canary Islands, Myrmokata diparoides gen.et sp.n. which parasitises ants of the genus Crematogaster in Cameroun, and Colpixys gigas sp.n. which destroyed more than 80% of the larvae of a Languriid beetle in the stems of elephant grass in Ghana. The genera Wichmannia Ruschka and Colpixys Waterston previously each included only one species.

Flight activity of aphids during 1969–71 in a Sitka spruce plantation in north-eastern Scotland was recorded by means of sticky traps. Two flight periods occurred, June–August and September–October. Fewer aphids were caught at 120 and 180 cm than at 60 cm above ground during June–August, while fewer were caught at 60 cm in September–October. After accounting for differences in wind speed at these heights, it was shown that aerial density was consistently higher at 60 cm. The first flight which comprised mostly Elatobium abietinum (Wlk.) was three weeks early in 1971; this was associated with the rapid increase in aphid population on spruce shoots, due to the preceding mild winter. Reinfestation by this species after spraying could follow under similar circumstances. Adelges laricis Vail. and A. viridis (Ratz.) sexuparae were caught in the first flight, and A. cooleyi (Gill.) gallicolae in the second; all galls on Sitka were by gallicolae of A. cooleyi. Aphis fabae Scop, was the most common species in the second flight.

Pedronia festeriana Lizer y Trelles is found on Cereus aethiops, Cleistocactus baumannii, Eriocereus bonplandii and E. martinii in Argentina. It severely distorts the growing tips and could possibly be used to control these weed cacti. The species is transferred to Hypogeococcus and redescribed from material collected recently in Argentina. Pseudococcus eriocerei is described as new also from the roots of Eriocereus bonplandii.

Increased doses of tepa applied by injection to female Diparopsis castanea Hmps. caused a progressive increase in sterility accompanied by a decrease in the number of eggs oviposited from the time of application. After an interval of three days it was shown by histological examination that injected doses of 10 μg of tepa induced degeneration of the developing oocytes and a shrinkage or resorption of some of the mature eggs. After Diparopsis male moths were treated with graduated injected doses of apholate, metepa and tepa and then mated with untreated females, considerable embryonic development without subsequent egg hatch occurred at the lower dosage levels. When tepa-treated Autographa gamma (L.) males at a dose of 10 μg were similarly mated with untreated females histological examination showed that the development of many of the eggs had been arrested at a very early stage; in some instances a greater development, although of an abnormal kind, had taken place.

Catches in light-traps adjoining cotton were obtained at the time of seasonal southward movement of the Inter-Tropical Front (ITF) in October, and during most of the following two months. Taxa studied were mostly Orthoptera and moths, many associated with sorghum, others long-distance migrants. Suction-trap catches at three heights up to 50 ft were obtained for short periods in October and November, and aircraft catches at 250 ft were also available on two days. Suction-trap catches of grass-feeding Homoptera suggest that displacement of these insects was associated with changes in wind direction marking movement of the ITF in October. The exact form of the displacement system in relation to the front cannot be reconstructed from catches at a single place, but it seems likely that proximity of the front at or soon after the time of a brief period of crepuscular activity stimulates insects to take flight and rise to 50 ft or more so that they are displaced. In many taxa, light-trap catches showed a regular pattern of increase, with only slight nightly fluctuations from a logarithmic trend, following full moon. Other increases were superimposed on this pattern at times when the ITF passed north of the trap site, and in some taxa particularly when it was far north. The pattern of change after full moon, shown most clearly in taxa with source populations close to the trap, was related to the moon's influence on the range of trap effectiveness. But various qualitative variations suggest that, in addition, aspects of behaviour or development may have adaptive relationships to the lunar cycle; variations include differences between taxa, particularly in timing of catch changes, and increasing proportion and decreasing maturity of females of certain taxa at the time of the regular increases in catch.

Observations on the behaviour of the predatory Reduviids Phonoctonus fasciatus (P. de B.) and P. subimpictus Stål were made in the laboratory. The sequence of events in the response to normal prey (Dysdercus superstitiosus (F.)) is described. The preferred site of the first puncture with adult prey was an antennal base, or the same region and the neck with nymphs. A strong tendency for the Reduviid to move its proboscis tip towards the prey's head region implied some perception of body form, which was found to depend on the presence of the prey's appendages. Such perception had no apparent influence on the intensity of the predatory response, experiments with models showing the most important visual stimulus eliciting attack to be that of movement. The scent of the prey greatly augmented the response to models, and chemical stimuli are presumably the basis on which the prey is selected and conspecific individuals, which resemble the prey in appearance, are recognised. The rarity of cannibalism by the adults showed such recognition to be well established, but sexual discrimination was minimal, both males and females behaving almost identically towards either sex. Adults of the two Phonoctonus species also failed to discriminate between their own and the alternative species, but since attempts at cross mating were unsuccessful their separate specific status seems justified.

Iraqerus neveosparsus sp.n. is described from Quercus spp. in Iraq and a key is given separating the new genus from Stegelytra Mulsant & Rey and Iberia Kirkaldy.

In laboratory experiments with Dysdercus fasciatus Sign, systematic testing of the stylets with a sucrose solution and distilled water has shown that the receptors mediating the salivary response to sucrose are located either on the maxillary stylets or at some site internal to them. Electronmicroscopical examination showed that the maxillary stylets were not innervated, and histological evidence further suggested the epipharyngeal organ as the site of gustatory discrimination. Dendrites located in the mandibular sclerites by means of the electron microscope could possibly have a proprioceptor function.

During studies on yellow fever in Bwamba county, Western Uganda, five non-stop series, each of six 24-h catches, were carried out in an uninhabited area of dense rainforest. All these yielded very large numbers of mosquitoes belonging to the Anopheles gambiae Giles complex. Measures of the central tendency, applied to summed results, show a “typical” pattern with a peak in the second half of the night. Examination of the results in detail reveals great variations in the biting pattern from day to day. These cannot be correlated with local weather conditions and their existence shows that considerable caution must be used in this type of analysis, except in well synchronised biting patterns.

Investigations were carried out on the ecology of Aedes (Aedimorphus) dentatus (Theo.) in the Ngong Forest near Nairobi between 22 June and 10 September 1971. Five 24-h collections on human bait showed that Ae. dentatus is predominantly a daytime biter with a peak of activity around sunset. At the time of its greatest activity none came to bite on the 7- or 10-m platforms. Of 94 blood-meal specimens, 50 were of Bovid origin (cattle), 18 from unidentified Bovids, 13 from unidentified mammals, one from a bird, three from any primate and nine did not react with the antisera used. Resting adults were frequently found underneath leaves of Hypoestes verticillaris, a herb which grows in partly shaded areas in the forest near the forest edge. A few adults came to bite in a house outside the forest not far from the forest edge. Breeding places were not found. The evidence for Ae. dentatus being a vector of yellow fever is inconclusive. The 33 other species of mosquitoes collected are listed.

Larothrips dentipes gen. et sp.n., possibly a pollinating agent of yam flowers in Nigeria, is described. The genus Thrips is defined and compared with the closely related monobasic genera Microcephalothrips and Larothrips.

In the tropics, the amount and the pattern of distribution of moonlight at and just after full moon produces alternating periods of continuous illumination and darkness which could provide photoperiodic cues for insects. Examples of possible photoperiodic effects induced by moonlight, taken from the published literature, include the flight activity and oviposition patterns shown by females of Heliothis zea (Boddie) and Diatraea saccharalis (F.) and crepuscular activity of mosquitoes. It is suggested that photoperiodic responses to moonlight could form the basis for a simple method of predicting such events.

In laboratory experiments at Langford, Bristol, agar membranes were superior to Parafilm membranes for the in vitro feeding of Glossina morsitans Westw. and G.austeni Newst. Temperature appears to be the primary stimulus for probing but agar membranes stimulate some probing, probably because of the humidity gradient above the membrane. Agar membranes also stimulate gorging, and enhance the effect of the phagostimulant adenosine 5' triphosphate (ATP). Agar membranes may simulate conditions on and in the skin of a living host by stimulating tactile and/or hygroreceptors in the mouthparts of the probing fly. G. morsitans females fed on blood containing ATP concentrations up to 5 × 10−3 M gave a higher reproductive rate and higher pupal weights. The rate of breakdown of ATP in bovine blood during one hour at 37°C indicated the amounts that need to be added to maintain optimal concentrations during feeding. There was positive correlation between pupal weight and reproductive rate of G. morsitans with the membrane-feeding system, but a maximum of only 80% of the optimal rate of reproduction and 80% of the optimal pupal weight was achieved. On living hosts this correlation did not hold, the pupal weights being higher, suggesting that the membrane-feeding system constitutes a stress factor. The stress of in vitro feeding does not apparently involve probing or gorging stimuli but its symptoms are those of nutritional deficiency. It is concluded that post mortem changes in vertebrate blood may affect quantitative aspects of feeding, or they may affect either the nutritional content of the blood or the ability of the insects to metabolise it correctly.

A histological examination of the cuticle of third-instar larvae of Hypoderma bovis (L.) and H. diana Brauer has revealed a large number of mounds with apical pits, which possibly act as chemoreceptors. The pits are in contact with nervous tissue in the epidermis by means of a rod or tube-like structure which passes vertically through the cuticle. Similar structures have been seen in the related genera Oedemagena and Przhevalskiana.

Time/mortality studies with Carabidae exposed to thionazin, phorate, disulfoton and menazon in an acid sandy loam soil were done in controlled laboratory conditions. Carabids were killed by soil treated with thionazin within dosage rates normally required for satisfactory control of nematode or insect pests of crops, i.e., 2·24–8·96 kg/ha, but menazon was virtually non-toxic. Soil moisture increased the speed of kill of Carabidae in thionazin-treated soil presumably by affecting processes of adsorption and desorption of the pesticide to soil colloids and by influencing burrowing behaviour. The speed of kill increased with a rise in temperature, mortalities occurring 2·2 × faster at 10°C, 8·1 × faster at 15°C and 11·8 × faster at 22°C than at 7°C, but was decreased by illumination which decreased the activity of the nocturnal Carabids. The addition of calcium carbonate to increase soil pH did not alter immediate mortality by thionazin but persistence was decreased. Speed of kill was negatively correlated with adult size of Carabid species that behaved similarly, small species such as Bembidion lampros (Hbst.) (mean weight 2·1–2·2 mg) dying 12–13 × faster than female adults of Pterostichus vulgaris (L.) (mean weight 195 mg). Species which burrowed in soil were more susceptible than those which did not, as were newly moulted or starved adults. At 15°C and in wet conditions the “ half-life ” of thionazin based on speed of kill in a soil of pH 6·1–6·7 was 1–2 weeks but when determined by gas-liquid chromatography was 3–4 weeks at 22°C. Leaching could account for the loss of up to 12% of thionazin from the top 9 cm of soil.

An intensive study was made of the ecology of species A and B of the Anopheles gambiae Giles complex at Kaduna, Nigeria, in October 1971. In collections comprising 383 larvae and 678 adult females from six villages, species A represented 82% of the larvae and 86, 89 and 91% respectively of the adult females caught by spray catches indoors, by biting catches outdoors and by exit traps fitted to windows. Larvae of species A and B occurred together in 42% of 57 breeding sites and showed no differential distribution among the various categories of site. Minor variations among the proportions of A and B females captured by different methods in the six villages showed no consistent contrasts. The only significant variation of the A/B ratio occurred at a temporary Fulani camp of cattle herdsmen, near Anguwun Maaza village, where an enhanced number of species B females were present indoors. At this Fulani camp a considerable number of both A and B females were feeding on cows outdoors and resting indoors during the day. Human blood indices of indoor-resting females were 88% for species A and 39% for species B at this camp, compared with 100% for both species at villages without cattle. Larval breeding places harboured an expectable range of insect predators. Predators of adult A. gambiae were not investigated although a predacious Emesine bug, Tinna elongata Villiers, was recorded in some huts. Numerous pathogen infections of larvae were observed, namely, Thelohania in 19%, Coelomomyces in 16%, unidentified gregarines in 7% and black-body virus in 3% of gambiae-positive breeding sites. Thelohania, Coelomomyces and gregarine infections were also encountered in adult females. Malaria sporozoite rates were 9·3% in species A and 5·5% in species B females. Some infections of stage III larvae of Wuchereria bancrofti were also seen in species A females.

Following an evaluation of the anatomical characters and habits of the Scolytini, four genera are recognised, namely Scolytus Geoffroy, Scolytopsis Blandford, Camptocerus Dejean, and Cnemonyx Eichhoff (=Loganius Chapuis, Ceratolepis Chapuis, Coptosomus Schedl, syn. n.). Two South American species, Camptocerus aquilus and C. rectus, having an ambrosial habit, are described as new.

Analyses were carried out at Salisbury, Rhodesia, on the relationship between fat content and residual dry weight in newly emerged adults of Glossina morsitans morsitans Westw., following incubation at constant temperatures between 16 and 32°C for laboratory material, and between 20 and 30°C for field material. The same relationship was investigated for field-collected and laboratory-produced larvae. Sizespecific rates of fat consumption were calculated from these data, and it was shown that the rate of change at temperatures below 20°C was of a different order to that at higher temperatures. Fat reserves in teneral flies reared in the laboratory at 16–32°C were shown to be adequate in flies of 4 mg residual dry weight for survival at rest for at least 24 h after emergence, over the temperature range likely to be encountered in the field. Considerably longer periods of survival were indicated for flies of the same size emerging from field-collected puparia. The latter exhibited a marked seasonal variation in size with the largest puparia occurring at the time of lower temperatures. Smallest puparia occur in the hot-dry season, but even under these adverse conditions fat reserves of most tenerals are adequate for survival for at least 24 h. It was concluded that lack of fat was not likely to cause heavy mortality of stages passed within the puparium over the temperature range 16–32°C. After emergence, survival of smaller flies would depend on their ability to obtain a blood-meal within 24 h.