An effective method of tsetse eradication has been demonstrated on a practical scale in country infested with Glossina morsitans morsitans Westw. in the Western Province of Zambia. An area of slightly over 600 miles2 (1 600 km2) was sprayed from aircraft five times, at approximately three-week intervals, with endosulfan in oil solution at an average of 8·2 gal/mile2 (14·4 litre/km2), so that the area dosage of active ingredient was 17 lb/mile2 (3 kg/km2) per application or approximately 2 oz/acre (0·15 kg/ha) for the whole operation. The insecticide was dispensed as an aerosol (most droplets of 20 μm diameter) made by injecting the spray liquid into the extended exhausts of the aeromotors. Post-spray fly-rounds showed that tsetse eradication was apparently achieved except near an unsatisfactory isolation barrier. The total cost was about K300/mile2 (£175 sterling).

The developmental biology of Telenomus remus Nixon is described from rearings within the eggs of Spodoptera littoralis (Boisd.). It has two larval instars and its developmental duration at 25°C is about ten days. Superparasitism can be easily induced in the laboratory, but only one adult emerges from each host egg.

In an inland area of the Gambia the density of flying mosquitoes at successive distances from a pair of bait-calves or an equivalent source of carbon dioxide was measured with ramp-traps to determine the maximum range at which orientation towards the bait was initiated. Thirty-six traps were operated at intervals of 7·5 m up to a distance of 60 m from the bait, on 66 nights. Anopheles ziemanni Grünb., Mansonia uniformis (Theo.) and Aedes spp. were responding to the presence of the baitcalves from a distance of 22·5–30 m; with carbon dioxide as bait the same species showed a clear response at 15 m but, with the doubtful exception of M. uniformis, not at 22·5–30 m. M. africana (Theo.) responded to both calf and carbon dioxide baits at 15 m but not at more distant ranges. Culex thalassius Theo. and C. univittatus Theo. showed a response at 7·5 m but not at any greater distance. C. decens group showed no response to either bait even in the nearest traps (7·5 m). The parous rate in Mansonia spp. varied with distance from the bait. Similar variation in the proportion of females infested with mites was not detected.

From trials with cotton (variety Stoneville 7A) grown on the Ord River Irrigation Area of Western Australia, the results of delaying insecticide protection of crops against Heliothis attack by four and eight weeks were re-examined. With each delay the crop set later when temperatures were cooler, the plants older and larger, and the accumulated insect damage greater. Yet there was no significant difference in the final number of bolls produced in each crop. The growth of cotton and the compensatory mechanisms of the plant indicated by the data were simulated by a simple computer model. A modification of the model to simulate the response of a cotton plant to attack by Heliothis larvae was also developed. Output from the model suggests that, under the conditions of the experiment, there is a theoretical maximum number of bolls produced by this cotton variety. To produce this maximum crop requires complete protection from Heliothis larvae, but the period of protection can be minimised.

The louvre-trap hut was designed to be cheaper and simpler to use than the verandah-trap hut. The eaves are closed, and mosquitoes enter by way of a row of five louvre frames and leave by a window fitted with a window trap. In three trials at Magugu, Tanzania, window traps fitted over one or all louvre frames showed that the efficiency of the louvres in preventing egress was 66–79% for Anopheles gambiae Giles, 51–73% for Mansonia uniformis (Theo.) and 74–78% for Culex pipiens fatigans Wied. Egress through the louvres of A. gambiae is only slightly more, and of M. uniformis much less, than through the eaves of a verandah-trap hut.

The genus Matutinus Distant is characterised and differentiated from Chlorionidea Loew, with which it was at one time synonymised. Descriptions are given of 26 species, 15 of which are described as new; three are transferred from other genera and a new subgenus is erected to accommodate one of them. Notes are given on their geographical distribution and host-plants.

Physcus seminotus Silv. (properly P. sp. nr. seminotus Silv.) and P. subflavus Annecke & Insley (Aphelinidae) are parasites of the sugar-cane scale insect Aulacaspis tegalensis (Zhnt.) (Diaspididae) in East Africa and they have been purposely introduced into Mauritius where A. tegalensis is an important pest. P. seminotus has brachypterous, flightless females and P. subflavus winged females but their biology is essentially similar. The parasites are arrhenotokous and fertilised and unfertilised eggs are deposited in different sites concomitant with development of female and male larvae on different primary hosts. Female larvae develop endoparasitically in A. tegalensis from fertilised eggs deposited in the host's body cavity. Male larvae develop ectoparasitically on immature Hymenoptera in A. tegalensis from unfertilised eggs deposited in the air-filled cavity of the latter's integumentary remnant. The males of the two Physcus spp. are therefore hyperparasitic and they frequently develop on the immature stages, both male and female, of their own kind (autoparasitism). Unfertilised eggs are laid by virgin females and also by mated females, the latter being able to deposit fertilised and unfertilised eggs at will, depending on the egg site encountered. Sexual dimorphism occurs at all stages, including the deposited egg. The preovipositional adult is the preferred stage of A. tegalensis for deposition of fertilised eggs and development of females is most rapid in such hosts. Development in young hosts is arrested until the hosts have grown to virtually their full size. The host of a male is apparently a matter of chance in so far as evelopment will occur on larval and pupal Hymenoptera of various species found in the empty, inflated, brittle integument of parasitised A. tegalensis. Only one individual, whether male or female, develops per host. Oviposition behaviour of mated females is such that superparasitism is largely avoided but it is liable to occur frequently when virgin females oviposit. Adult females will feed on the body fluids of A. tegalensis that are released by insertion of the ovipositor and also on sugary fluids. They live a month or more, ovipositing continually at a gradually decreasing rate, and laying usually 50–100 eggs.

The use of standardised artificial substratum units (SASUs) for sampling preimaginal populations of Simulium is reviewed and the results then given of experiments with SASUs in rivers and artificial streams in West Cameroon in 1968–70. The increase of downstream drift of larvae by night is attributed to the increased activity of associated fauna at night. The numbers of larvae settling on SASUs is partly afunction of how long the latter have been set and partly due to the pattern of fluctuation in river depth. Any particular SASU appears to be selective in relation to the different species of Simulium available for settlement. A new index of uniformity is proposed for comparing the diversity of Simulium faunas occurring on different substrata.

An improved technique for small-scale rearing of Rhodnius prolixus Stal on rabbits is described. For feeding, the bugs are presented in tubes closed with silk to the shaved stomachs of rabbits; between feeds the bugs are held in 1-lb glass jars at 28°C. Large-scale rearing by this method was precluded by the amount of handling required. Feeding on defibrinated blood resulted in a survival rate to the adult stage of less than 10%, but sheep on which up to 6 600 fourth instar could be fed weekly proved satisfactory hosts, although they had to be replaced after 1–9 weeks as they developed a resistance which prevented the bugs feeding. A large-scale rearing technique is described in which instars 2–5 are presented to sheep in wire cages covered with nylon netting while instar 1 and adults are fed on rabbits; between feeds the bugs are housed in 3½–7-lb glass jars or in net-covered cages. A production of 4 000 fed fourth instar or larger bugs per week for 18 months was achieved, sometimes reaching 7 000 per week.

Descriptions are given of the immature and adult stages of Tenuipalpus ghanii sp. n., and the characters distinguishing this species from T. punicae Pritchard & Baker and T. granati Sayed are listed. In West Pakistan the preferred host-plant is Pyrus communis. T. ghanii overwinters in the adult stage; it reproduces parthenogenetically and populations of all stages reach their peak in June or July. Of the four predators recorded, Exothorhis sp. (Eupalopsellidae) was the most abundant but was restricted to Pyrus communis.

To obtain dietary information for the laboratory rearing of Planococcoides njalensis (Laing) the bark tissue of cocoa shoots and mealybug honeydew were analysed for their free sugar and amino acid contents. Paper chromatographic analysis showed the bark tissue to contain mainly sucrose, with smaller amounts of glucose, fructose and raffinose. The proportions of sucrose and glucose+fructose in the honeydew were 24–27% and 24–35%, respectively, with the bulk of the 80% ethanol fraction composed of ketose oligosaccharides. The latter compounds may result from the glycosyltransferase action of mealybug invertase which has been partially characterised. Of the free nitrogenous substances, ethanolamine, asparagine, cysteine, lysine and γ-aminobutyric acid, alanine and glutamic acid are preferentially absorbed. It is concluded that these are important mealybug metabolites, which may be supplied with small amounts of sugar in future liquid-diet trials. Their approximate physiological concentrations were estimated by a semi-quantitative method.

A flight mill is described which permits the automatic measurement of flight duration, speed, periodicity and wing-beat frequency.

Neogonatopus brunneicollis reared from Cicadellids in Israel, and Pseudogonatopus saccharivorae from Saccharosydne saccharivora (Westw.) (Delphacidae) in Jamaica, are described as new. N. dimidiatus (Sahlberg) and Gonatopus ruficollis Hellén are redescribed from the holotypes. Descriptive notes are given on two new species of Neogonatopus, parasites of Cicadellids, and one of Pseudogonatopus, parasite of a Delphacid, in Israel.

By means of sticky traps and a suction trap, it was demonstrated on a plot of sugar-cane at Kawanda Research Station, Uganda, that large numbers of crawlers of Aulacaspis tegalensis (Zhnt.) become airborne (up to 10/m3). The numbers increase with wind speed up to about 2·0 m/s and then remain constant, but are depressed by increasing humidity. In laboratory experiments, crawler survival was reduced by high temperatures (30°C) and low humidities (30% r.h.), but some individuals should survive the extreme conditions sometimes experienced if airborne from morning until evening. On hatching, crawlers move upwards and towards the light, but downwards in the dark; movement is inhibited by high humidity. These behaviour responses indicate hat the presence of crawlers in the air is not accidental but a dispersal mechanism. At Arusha Chini, an isolated sugar estate in Tanzania, sticky-trap catches downwind of a windbreak confirmed that airborne dispersal of crawlers is a major source of infestation. It is shown that air currents could have carried crawlers to Arusha Chini from a source on the Kenya coast, 260 km to the east.

In arabica coffee estates at Kahuguni and Magogoni, Kenya, female giant looper moths, Ascotis selenaria reciprocaria (Wlk.), rested on coffee tree stems at 60·7 ± 9·8 cm above ground and males at 65·7 ± 6·6 cm; most eggs were laid less than 122 cm above ground. In the laboratory, females laid on average 693 eggs in 5·3 batches; peak oviposition and fertility were 2–3 days after emergence. Life span was 8·3 days for females and 10·4 days for males; at death females contained 1·4 spermatophores each (1·1 in field-collected specimens). It is concluded that hand-picking of moths will have little control value unless done the day after emergence, but that tree-banding with residual insecticide 122–130 cm above ground would kill 90% of the emerging larvae.

The biting rates of Culicoides furens (Poey) and C. barbosai Wirth & Blanton on Florida Beach, Jamaica, were observed in 50 trials conducted 40–115 min after dawn from 5 February 1960 to 10 February 1961. The data were logarithmically transformed and non-zero biting rates standardised. Biting rates of both species varied markedly from week to week but monthly mean rates were significantly higher and lower for C. furens in September (111·4) and March (13·7), respectively. Monthly mean rates for C. barbosai fell into three groups, (i) March-June (15·3); (ii) November–December (9·1); (iii) January–February and July–October (3·1). These changes were negatively correlated with mean sea level. Biting rates of C. barbosai were highest at new moon (10·3) and lower but similar (4·3–5·2) for the other three phases of the moon. Those of C. furens were maximal at new moon (62·8), minimal at full moon (20·4) and intermediate (35·9, 39·5) at the quarters. The lunar effect is assumed to act through the tides. There were no significant differences between the standardised biting rates at different times after dawn. In a comparison of the quantitative effects of ten factors on the biting rates of C. furens, C. barbosai and Leptoconops becquaerti (Kieff.), most important were month of year and wind speed; of less importance were lunar cycle, temperature, collector and limb exposed; while site position, intensity of illumination, time after dawn, saturation deficit were of minor or no importance. It is concluded that the biting rate of L. becquaerti should be the least affected by changes in these factors, C. barbosai more affected and C. furens most affected.