Between January 1965 and August 1967 49 species of biting flies were caught in Langridge and Fredeen traps and from bait animals in western Uganda. Catches were recorded daily, and monthly catches (geometricmeans) of the species most frequent on bullocks were plotted as percentages of the year's catch. Haematobia minuta (Bez.) was the only species to show a unimodal peak; this is attributed to maintenance of soil conditions suitable for the larvae during the short rains (September-November). Bimodal peaks are shown by Haematopota brunnescens Ric, H. patellicorne (End.),Tabanus par Wlk., Stomoxys inornata Grünb., S. nigra nigra Macq. and Haematobosca squalida (Grünb.) (adversely affected by severe dry conditions), by T. taeniola P. de B. and T. thoracinus P. de B. (emergence from pupae coincides with the beginning of the rainy seasons (March-May and September-November)), by Stomoxys omega Newst. and Haematobiaspinigera Mall, (minimum numbers in the wet months September-October), and by species of Haematopota, Tabanus, Chrysops, Stomoxys and Haematobosca(breeding occurs in the rainy seasons). Ill defined cycles are shown by Chrysops distinctipennis Aust, C. longicornis Macq., S.ochrosoma Speiser and females of S. calcitrans (L.) ; Glossina fuscipesNewst., G. fuscipleuris Aust. and G. pallidipes Aust. showed minimum numbers in September-October.

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.

The north-western European species of the vitripennis, pallipes, octonarius, triangulator, fraternus, formosus, parasitellae, metacarpalis and circumscriptus-groups of Apanteles are revised. Sixty-five species are dealt with, of which twenty-four are described as new. One species, A. exiguus (Haliday), is lifted from synonymy. Brief notes are added on North American species of the circumscriptus-group in the British Museum (Nat. Hist.) to assist their eventual correlation with the European species. Reference is also made to two species of Hypomicrogaster.

The literature published during 1964–72 concerned with the ecology and control of Glossina is reviewed and put into context with previously published information. Thirty species or subspecies of Glossina are recognised. Improved methods of sampling have been developed which catch many more females of the morsitans group than other methods and allow more accurate estimates of population density and structure to be made than has been possible hitherto. New concepts of the activity and behaviour patterns of G. morsitans Westwood have been developed from work carried out both in the field and in the laboratory. Detailed studies on resting sites have been followed by successful control campaigns based on the selective use of insecticides. Most large-scale control campaigns during the period under review were based on applications of insecticides from the ground; other control methods used were aerial applications of insecticides, mechanical clearing of vegetation, selective game destruction and a small-scale project using the sterile insect release method. Techniques for identifying and assessing trypanosome infections in Glossina are described and a Table is given of infection rates in various species of tsetse. Differences in observed infection rates can result according to the time and method of sampling but actual infection rates are affected by a variety of factors including the maintenance temperature of puparia and adults, the age of the fly at the time of the infective feed, the age structure of the tsetse population and the hosts on which it feeds. Genetic differences in infectibility may occur between different individuals of a single species and certainly occur between different species.

Following examination of Cicadelloidea off potato, castor, millets and berseem from Simla, India, and of some of Distant's type specimens, the genera Jilinga, Pseudosubhimalus and Sarejuia are described as new, and new combinations and synonymies given ; two new species are also described under Aconurella Ribaut and Sarejuia. Dio Distant, Erythridea Ribaut and Erythria Fieber are considered to be distinct, and a key to these genera is given.

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.

The effect of temperature within the range 10–30°C on Metopolophium dirhodum (Wlk.), Rhopalosiphum padi (L.) and Macrosiphum avenae (F.) was measured in controlled environment cabinets. Development rates increased with temperature to a maximum at 20°C for Metopolophium dirhodum, 22·5°C for Macrosiphum avenae and 25°C for R. padi, decreasing thereafter to zero by 30°C when all the nymphs died. The fourth instar and pre-reproductive adult appeared to be affected at temperatures below those for the younger instars. Mortalities of immature M. avenae were similar between 10° and 25°C, but more immature Metopolophium dirhodum died at high, and R. padi at low, temperatures. Survival rates decreased with increase of temperature, and fecundity was largest at 20°C. Rates of increase became largest at 20°C for M. dirhodum and Macrosiphum avenae and at 25°C for R. padi. Above 15°C, R. padi had a 4–16 times larger capacity for increase than the other two species because it developed faster and achieved its rate of maximum fecundity sooner.

Records were kept of the catches of tsetse fly by three types of traps, the Langridge box screen, the Swynnerton awning screen, and a modification of the latter incorporating a screen skirt, in the South Busoga fly-belt, Uganda, where Glossina pallidipes Aust., G. fuscipes Newst. and G. brevipalpis Newst. are abundant. Only two specimens of G. brevipalpis, but large numbers of the other two species, were caught, by far the largest catches being obtained by the awning screen-skirt trap.

The biology of Paropta paradoxus (H.-S.), a new pest of the grapevine, was studied in field and laboratory during 1962–1972. Descriptions are given of the imago and developmental stages. The life-cycle is completed in 1–3 years. Adults are active during April–September, and eclose mostly during the day with a male/female ratio of 0.65 (3.3 in UV light-trap catches). Light induces a deep torpor in most adults. After mating, which lasts 30–60 min, females lay up to 275 eggs in their life span of 1–14 days (males 2–13 days). In the vineyard eggs are glued under loose bark, in batches of 15.6 (1–63), and hatch in 20–32 days. The neonate larvae disperse and settle under loose bark where they begin feeding; penetration of the wood is mainly through dried stubs of pruned canes, and galleries are excavated along the axes of stems and branches. Larvae may also develop under dry bark. The pest overwinters as active immature larvae and diapausing mature, prepupal larvae. The pupa is usually formed in the larval galleries, and lasts 16–45 days. In heavily infested vines the pupae may be cannibalized by larvae; both larvae and pupae may be preyed on by woodpeckers.

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.).

In a study of aphids and their parasites, hyperparasites and predators in a field of cereals at Rothamsted Experimental Station in 1970–71, samples were taken by counting specimens in 0·3-m lengths of row and by means of a suction trap set 12·2 m above ground and 0·5 km away from the field. Migrant aphids (Metopolophium dirhodum (Wlk.) and Macrosiphum avenae (F.)) and Braconid parasites (Aphidius spp., Ephedrus plagiator (Nees) and Praon volucre (Hal.)) were caught from April–May to August–September, with most from mid-June to August, whereas hyperparasites (Phaenoglyphis sp., Lygocerus aphidivorus Kieff., Asaphes vulgaris Wlk., Coruna clavata Wlk. and Alloxysta sp.) occurred for more of the year. Of the six parasite species attacking aphids on cereals in 1970–71, three Aphidius spp. were more common than E. plagiator and Praon volucre. Parasitism was higher and aphids were fewer in 1971 than in 1970. In the field, more than 80% of the mummies were of old nymphs; parasitism of live old nymphs and apterae was similar, larger than for alatae, and larger for Metopolophium dirhodum than for Macrosiphum avenae. Hyperparasitism by five species affected parasitism, especially in 1970. Migrant Coccinellids were trapped at the start and end of aphid infestations on cereals, Syrphids mainly in July and August, and other predators for longer. The commonest predators were Coccinella septempunctata L. and Propylea quatuordecimpunctata L. in 1970 and Syrphus balteatus (Deg.) in 1971; the others were scarce. July populations of aphids were primarily reduced by the Syrphids.

The emission and form of the spermatophores of Eriophyes sheldoni Ewing are described and illustrated. Glued to the substratum by a drop-like pad which varies in shape, they consist of a stalk with a basal stiff section and a distal flexible part ending in a strongly convex lens-like head, in which the sperm mass is kept. The fine structures of the adult integument, characteristic of this species, are described and illustrated.

Two field strains of Lucilia cuprina (Wied.) of different susceptibilities to diazinon were selected over 25 generations by immersion of first-instar larvae in aqueous emulsions of diazinon for five minutes ; the resistance of the larvae and adult females was compared with a standard laboratory susceptible strain. Resistance increased rapidly in both strains, reaching a maximum for adult females (R.F. = 5–6) in generation 3 and for larvae (R.F. = 46–60) in generation 6. After removal of selection pressure at generation 8 the resistance factor fell to 20–24 by generation 25. Because the resistance mechanisms are known to place their carriers at a disadvantage in the absence of selection pressure, the practical implications of the rapid increase in resistance must await results of experiments with known genotypes.

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.

After exposure for 24 h in polypropylene envelopes impregnated with the test substance, larvae of Boophilus microplus (Can.) are placed on a hot-plate (40°C) under light to stimulate movement among the survivors. The larvae are drawn one at a time into a suction bottle through a metal capillary into which is built a photo-electric cell that is actuated by each larva as it passes through. The electric impulses are transmitted to a counting device and recorded.

Responsiveness to stimuli eliciting probing was measured in individual, suspended males of Glossina morsitans Westw. The standard stimulus was a warmed foam rubber ball offered from below; a positive response was recorded if the fly exsheathed its haustellum and probed the foam. During four days without food, probing responsiveness increased linearly from zero in mature flies, but with an initial step-up in tenerals. Each day's increase was steeper than the overall rate, and apparently modulated in the V-shaped pattern typical of other responses in tsetse flies. Starvation is thus seen to induce changes in feeding thresholds which parallel those induced in flight behaviour.

The long range orientation of West African mosquitoes to birds was studied using ramp-traps set up 3–23 m from the bait. The baits comprised chickens, ducks, pigeons and the carbon dioxide equivalent of the chickens. From the pattern of convergence of mosquitoes to the baits, it was shown that Anopheles melas Theo. and Culex thalassius Theo. were orienting to all the bird-baits from distances of at least seven metres. Responses to carbon dioxide were only apparent at a distance of three metres indicating the greater range of effect of the chickens over their carbon dioxide equivalent. Mosquitoes of the largely bird-biting C. decens group showed no long range response to any bait, even though they were entering pigeon-baited traps and to a limited extent feeding on the birds. Catches of A. melas in bird-baited traps were larger at the foot of a tall tree than in the foliage at 5·33 m; for Culex spp. the converse was true. Catches of Culex at 5·33 m outside the tree were smaller than within the foliage.

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 survey of alcohol dehydrogenase (Adh) in Culex tritaeniorhynchus Giles has uncovered five electrophoretic variants among laboratory strains. Detailed genetic analysis revealed that these variants are inherited as codominant alleles at a single locus. The Adh locus has been assigned to linkage group III between s and cl. A survey of a natural population from Lahore, Pakistan, revealed the presence of four of the five variants and suggests the possibility of using this enzyme polymorphism to monitor a release programme. Substrate specificity tests suggest that this enzyme can utilize almost any aliphatic primary alcohol as a substrate.

Leafhoppers collected from dying pawpaw trees in Dominica are described as new under the name Solanasca dominica. This genus is created for the solana group of Empoasca Walsh which is characterised by the shape of the aedeagus; a key is given to the 26 species now known.