In Rhodesia from 1966 to 1970 Glossina morsitans Westw. and G. pallidipesAust. in natural and artificial refuges were studied by in situ counts or captured by a hand-net, mechanical, electric or sticky trapping, or a curtain drawn across the entrance. A modification of mechanical trapping permitted investigation of the pattern in whichtsetse vacated a refuge. Coolness and shade were features of effective refuges. Large numbers of tsetse utilised refuges only during the hot dry months of September, October and November. Entries occurred when temperatures reached 32°C in the morning and continued until mid-afternoon; exits occurred mainly in the evening. G. morsitansentering at 12.00–14.00 h were relatively abundant in fat; G. pallidipes entering at 12.00–16.00 h were relatively abundant in residual blood-meal. Greatest numbers of tsetse occupied refuges in naturally shaded situations such as riverine fringes. Few of the many tsetse marked in refuges and releasedwere found again at the refuge of marking. Artificial refuges were not used extensively for larval deposition. Comparisons between the catches from refuges, oxen, Morris traps and a fly round illustrate the problem of obtaining representative samples of tsetse populations. The application of insecticides to natural refuges is a policy of merit.

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.

Sublethal topically applied doses of the carbamate insecticide carbaryl and injection of certain s-triazine chemosterilants to female Diparopsis castanea Hmps. enhanced the rate of oviposition without reducing fertility. Treatment of male moths with carbaryl and certain s-triazines often caused an increase in mating disfunction expressed as an absence of sperm from the spermatheca after an apparently normal mating, permanent copulation or spontaneous extrusion of a spermatophore. No evidencewas found for a direct sterilising action of the chemosterilants against the insect sperm.

The Ponerine ant Odontomachus haematodus (L.) tendsthe aphid Toxoptera aurantii (Boy.) and a StictococcidStictococcus sjostedti Ckll. on cocoa in Ghana but predates the mealybug Planococcoides njalensis (Laing). Tents are built over the first two, largely of soil particles. Honeydew is collected in the mandibles and carried to the nest or may be accumulated and eventually drunk. Some of the soil used in the tents is infected by blackpod sporangia. Tending homopters is restricted to the immediate vicinity of the nest. The mutualism practised has evolved independently of its occurrence in higher ants.

The choriothete of Glossina austeni Newst. was examined in dissections and in histological sections. The choriothete is a highly modified invagination of the anteroventral wall of the uterus forming a tongue-like organ broadly attached to the floor of the uterus. Secretory cells in the choriothete epithelium produce a mucoprotein which finds its way onto the surface of the choriothete through pores in the cuticular intima. The mucoprotein serves as cement to fasten the chorion to the surfaceof the choriothete. Muscles in the choriothete maintain a tension on the ohorion and aid in the removal of the chorion when it is torn by the egg-tooth of the first-instar larva.No evidence was obtained which suggested that the choriothete served a similar function during larval ecdyses.

Melanagromyza convolvuli from the stems of Convolvulus arvensis in West Pakistan is described as new.