Acetone at a dose of 1 μl was one of the least toxic of 11 solvents applied topically to fifth-instar nymphs of Dysdercus fasciatus Sign., while ctronellal, n-dodecane and n-tridecane at a dose of 0.5 μl were the most toxic. Acetone applied at 0.3 μl to third- and fourth-instar numphs caused negligible mortalities but about 60% of the treated nymphs gave rise to abnormal adults which, although capable of mating, laid eggs which were significantly less fertile than those from treated individuals which emerged as normal adults. These abnormalities could be attributed to a hormonal imbalance. Apparently normal adults arising from nymphs treated at the third instar with 0.6 μl acetone had 35% fertile matings (controls 70%) due to interference in the production and transference of motile sperm. The effects of acetone as a solvent in laboratory experiments could therefore be confounded with those attributed to juvenile hormones.

Laboratory experiments with juvenile hormone analogues on Cydia pomonella (L.) showed that Cecropia C17 juvenile hormone (methyl 10,ll-epoxy-3,7,ll-trimethyl-2,6-dodecadienoate) was the most active of the 28 compounds tested. When applied to four-hour-old eggs at 0.1 μg/egg, the hormone caused 100% failure in embryogenesis, while the other compounds were at least five times less effective. Depending on the time since ecdysis and the dose, juvenile hormone mimics applied to last-instar larvae resulted in a wide range of intermediate forms. Against three-day-old last-instar larvae, the Cecropia C17 hormone gave 100% inhibition of development at a dose of 1 μg/larva, while three other compounds (methyl 10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate, ethyl 11-chloro-3,7,11-trimethyl-2-dodecenoate and ethyl 3,7,11-tri-methyl-2,4-dodecadienoate) gave the same effect at 2–5 μg/larva. Against newly emerged adults, the last two compounds at 10–50 μg/insect reduced fecundity and fertility to 0–81% and 0–50%, respectively, of their normal levels.

Day and night catches of biting flies (excluding Culicidae) were made from bullock, buffalo and at light at Katookye, western Uganda, between July 1966 and August 1967. The 39 species caught were classified according to the time of day at which they bit. The seven Groups and the most commonly caught species are as follows: Group 1, Ceratopogonidae (purely nocturnal) and Glossina fuscipleuris Aust., Stomoxys ochrosoma Speiser and Haematobosca squalida (Grünb.) (diurnal and nocturnal); Group 2 (early morning peak),Haematobia minuta (Bez.),H. spinigera(Mall.)and H. thirouxi (Roub.); Group 3 (mid-morning peak), Tabanus taeniola P. de B. and T. thoracinus P. de B. Group 4 (mid-morning and late afternoon peaks), G. pallidipes Aust. males and Haematobosca latifrons (Mall.); Group 5 (early morning and evening peaks), Haematopota brunnescens Ric. females, H. patellicorne (End.) females, Stomoxys taeniata Big., S. nigra Macq., S. inornata Grünb. and S. omega Newst.; Group 6 (midday to mid-afternoon peak), G. pallidipes females, H. brucei Aust. females, T. par Wlk. females and Chrysops distinctipennis Aust. females; and Group 7 (progressive increase in biting from morning till evening), G. fuscipes Newst. and S. calcitrans (L.).

The melon weevil, Acythopeus curvirostris (Boheman), is a speciescomplex comprising at least four allopatric forms, here regarded as subspecies. Of the seven available species-group names, three are retained for subspecies and four placed in synonymy; an eighth name is proposed for the fourth subspecies. The generic and subgeneric placements of the melon weevil and its relatives are discussed. The following check-list of the species of Acythopeus (Carpobaris) summarizes the present position (synonyms all new): A. (C.) curvirostris (Boheman) (=traegardhi (Aurivillius)), A. (C.) c. granulipennis (Tournier) (=colocynthae Voss, globulicollis Voss, cucumidis Voss), A. (C.) c. persicus subsp. n., A. (C.) c. citrulli Marshall, A. (C.) alcyoneus (Erichson) (=atrocoeruleus (Boheman)), A. (C.) cucurbitae (Marshall), A. (C.) speciosus (Gerstaecker), A. (C.) coelestis (Pascoe). (Acythopeus francisci nom.n. = A curvirostris Pascoe, 1874, nee Boheman, 1844.) Simple biometric procedures indicate differences between the subspecies of A. curvirostris; some characters show clinal variation. The melon weevil occurs across the Sudan Belt, in the Middle East, Iran and South India. It is generally a minor and transient pest of cucurbit fruits. One parasite and one predator are known.

To evaluate the effectiveness of the introduced Hymenopterous parasites Apanteles circumscriptus (Nees) and Enaysma splendens Delucchi in the control of Phyllonorycter messaniella (Zell.) samples of leaves were taken from infested oaks during 1969–70. In Christchurch there were three generations of P. messaniella per year with spring, summer, and autumn emergence periods. Infestation on deciduous oaks was negligible in some areas but was 6.3 mines/leaf in the lower crown of oaks close to evergreen oaks on which P. messaniella overwinters. On deciduous oaks total parasitism ranged from 30% to 80%. Apanteles was the most abundant parasite but Enaysma assumed almost equal importance on oaks with low infestations. Pnigalio pectinicornis (L.), a self-introduced parasite, has been almost completely displaced by the other two parasites since their introduction in 1957. The infestation intensity recorded in Nelson (2.3 mines/leaf) was much lower than the level reported before the release of the parasites (40+ mines/leaf), but still much higher than levels in Europe.

A species of Mompha, discovered on creeping water-primrose Ludwigia adscendens (Onagraceae) in Assam, N.E. India, is described as new and named Mompha ludwigiae. The eggs, larval and pupal stages are also described. Females lay up to 150 eggs in 3–7 days; development from egg to adult takes 3–5 weeks, the larva at first mining the leaves and later feeding externally on terminal shoots. The larvae could be reared on Oenothera rosea, L. perennis and L. octovalvis in the laboratory, but no host-plants other than L. adscendens were found in the field. A Eulophid parasite, Euryscotolinx sp., has been bred from pupal cocoons.

Studies on mosquitoes of the Anopheles gambiae Giles complex at Bwamba, Uganda, showed that the newly recognized sibling species D may be restricted to breeding areas where waters contain unusual solutes, the effluent from hot springs at Buranga being particularly favourable. Two other members of the complex, species A and B, were also detected in the neighbourhood apparently breeding only in more normal situations. Species D specimens were usually identified cytotaxonomically, from the presence of XR potytene chromosomes of the type also occurring in species C and A. melas (Theo.) (neither of which is known from the area). Most species D females have distinctively pale palps, a valuable although limited distinguishing feature. Features of setation on larvae and pupae were discerned which might serve usefully as meristic chaetotaxonomic factors, at least locally, if tested further. Although it is unquestionable that a large proportion of species D females forage in the Semliki forest, feeding on primates, bovids, suids or unsuspected hosts, it was demonstrated that many species D females are markedly anthropophilic and display strong endophilic and endophagic tendencies, to the extent that they may be primary vectors of human malaria and filariasis over a limited range. Species D males were rare indoors and remained mainly within the forest, where great numbers rest low on vegetation in company with unfed females, near to breeding areas of brackish marsh. Two polymorphic chromosomal inversions in species D apparently embody the genetical causes of its differentiation. Cytogenetical evidence indicates that species D is phylogenetically nearly intermediate between A. melas and species C of the A. gambiae complex.

In this method the toxicant is absorbed with blood serum onto a loose roll of chromatography paper; first-instar larvae of Lucilia cuprina (Wied.) are inserted into the air spaces of the roll and allowed to feed. Mortality of the larvae is assessed 24 h later. Typical results using diazinon, dichlofenthian and chlorfenvinphos against susceptible and resistant strains of L. cuprina showed larvae to have resistance factors 6–8 times higher than those for adults determined by established techniques.

A method for collecting flying insects is described, developed for studies on the dispersal of Simuliidae. The apparatus consists of a net mounted on the roof of a motor vehicle, leading to a catch-segregating apparatus within it, such that the catches over any desired distance at speeds up to 48 km/h can be segregated without stopping until 50 catches have been obtained. The volume of air filtered is measured with a counter anemometer mounted in the net mouth. Specimen results for one day are given as an illustration of the efficiency of the method.

An account is presented of the distribution and amounts of moonlight in latitudes near the equator. This includes a Table on the amount of moonlight for each hour of the night throughout a standard lunar cycle, applicable to any locality between 10°N and 10°S, and a Table of standard groups of moon phase which can be used at any locality irrespective of latitude. The construction of these Tables is described in detail and their use briefly discussed. A method is described which enables light-trap catch records to be arranged for analysis directly against moon phase.

Nightly light-trap catches of insects, covering periods of 2–5 years, from two sites in Africa within 10° of the equator are examined in relation to the regular changes in night illumination of the lunar cycle. For several species average log catches at different phases of the moon are almost linearly related to (log) night illumination, catches of some species, such as Isoptera and Bostrychidae, increasing and of others, such as Marasmia trapezalis(Gn.) (Pyralidae), Lampyridae and Dorylus spp. (Formicidae), decreasing with moonlight. Relative catches of M. trapezalis and Bostrychidae varied by a factor of 30:1 between no moon and full moon. Analysis of whole-night catches gives some evidence on the pattern of insect activity through the night, identifying Syntomis monothyris (Hmps.) (Ctenuchidae) and Stemorrhages sericea (Dru.) (Pyralidae) in particular as early morning fliers. Evidence on how night illumination affects catch, and on the times of night when illumination has most effect, is consistent for the two sites and for different years. However, any adjustment of nightly catches to those expected under standard conditions of illumination can only be approximate. Although most of the differences between catches at different moon phases are accounted for by night illumination, many factors influence catch on an individual night, and moonlight is a major factor only for certain species. A hypothesis about how a light-trap may affect insect behaviour allows changes in catch of some species over the lunar cycle to be explained by the influence of background illumination on trap effectiveness.

The genus Phytolyma is defined and a key is given to its four species. Two of the species, P. minuta and P. tuberculata, are described as new, another (P. fusca Alibert) is elevated from varietal status and the fourth (P. lata (Walker)) is redescribed. The host-plants are African forest trees, Chlorophora spp. and Morus sp. (Moraceae).

A study, begun in 1966 at Edinburgh University, and completed during the ensuing 30 months at Muguga, Kenya, of the developmental periods of Rhipicephalus appendiculatus Neum. under controlled temperature and humidity was carried out to provide basic background information for an intensified FAO/EAVRO programme of East Coast fever research. Quantitative data are given on the preoviposition, pre-eclosion and, for larvae and nymphs, premoulting periods at three constant temperatures, 25, 21 and 18°C. The rate of development at all stages was accelerated by raising the temperature and retarded by lowering it. A “pre-immobilization period” which precedes the entry of engorged larvae and nymphs to the true moulting process also appeared to be temperature dependent. Development became very prolonged as temperatures fell below 18°C, being negligible at 15°C and having apparently ceased altogether at 9°C. Continuous exposure for more than two or three days to temperatures of 4°C and below were lethal to all engorged instars. Humidity (controlled at levels between 18 and 87% r.h.) had no influence on the rate of development. It is concluded that within limits of tolerable aridity, developmental periods would be completed within the times dictated by temperature regardless of the level of humidity or changes in the level of humidity. No suggestion of any diapause mechanism was discerned.