An account is given of the simultaneous control of three species of tsetse fly by the selective application of insecticide to vegetation within an area of 16 sq. miles along a seasonal watercourse in Northern Nigeria constituting a permanent habitat of Glossina palpalis (R.-D.) and G. tachinoides Westw. and a hot-season concentration area of G. morsitans Westw. subsp. submorsitans Newst. The ecological zones concerned centred on small lakes fringed, in succession outwards, by open swamp, swamp woodland, swamp forest, riparian forest and riparian woodland, the whole being bounded by savannah woodland populated by G. morsitans in the wet season. All except the forest elements were subject to seasonal fires.

Against G. morsitans, insecticide was applied to the principal resting sites of flies in their hot-season concentration habitats, namely, the basal 5 ft. of shaded tree trunks over 9 in. in diameter, or 5 in. where stands were dense, in, chiefly, riparian woodland and forest. Against the other species it was applied to a height of 2½ ft. on stems, trunks and exposed roots in riparian forest and the margins of swamp forest, which were favoured as pupation sites and in which it was therefore believed that adults might rest.

A wettable-powder suspension containing 3¾ per cent. DDT was applied by pneumatic knapsack sprayer in quantities short of run-off. Temporary reduction of the strength to 2½ per cent, had no detectable effect on control.

Regular fly patrols showed an initial reduction in apparent density of G. morsitans by four-fifths, but spot checks detected a residual population that persisted up to two months in small areas. These were resprayed so as to include trunks of 5 in. diameter and branches over 3 in. in diameter at heights of 6–12 ft. The apparent density of the other species declined after treatment by over nine-tenths, in both treated and untreated zones, but following catches of a few teneral adults, indicating persistent or recurrent populations in limited areas, these were resprayed using an emulsion containing 3¾ per cent, dieldrin.

Treatment began in January 1961 and to date (April 1963) no fly has been detected since April 1961, despite repeated re-surveys. The approximate cost of labour, equipment and insecticide was £3,000; an attempt at reclamation in 1926–29 by sheer-felling over seven sq. miles, which achieved only temporary success, had cost £3,000, with recurrent annual re-slashing costs of £250, equivalent to £12,000 and £1,500, respectively, at present-day costs for labour.

Three methods of chemical control of Melanagromyza phaseoli (Tryon) on bean (Phaseolus) have been investigated, these comprising seed and soil treatments and spraying of the foliage.

Organophosphorus and chlorinated hydrocarbon insecticides have been tested, chiefly as seed soaks, in the control of the pest. Applied in this way, the former gave poor protection, whereas the chlorinated hydrocarbons, especially the cyclodiene compounds, aldrin, dieldrin, endrin and chlordane, gave adequate protection. Reduction of the period of soaking led to better germination of treated seed. When seed-borne diseases were present, soaking in water or insecticidal solution enhanced their incidence. Bean varieties varied in their response to soaking in water or the insecticidal fluids used, the germination of most varieties being adversely affected. Endrin 20 per cent, emulsifiable concentrate (E.C.) used at a dilution of 1:250 as a soak for six hours or at a dilution of 1:125 for three hours or 1:50 for momentary dipping or up to an hour's soaking, gave good germination and protection from M. phaseoli with the climbing bean variety Kentucky Wonder but reduced very considerably the germination of several other varieties.

Where soil was treated with various insecticides for control of M. phaseoli. pre-sowing treatment was more effective in protecting the bean plant from this seedling pest than treatment given after seedling emergence. Soil treatment with endrin did not induce phytotoxic symptoms in those varieties that were adversely affected when the seeds were soaked in emulsified solutions of endrin.

Foliar spraying with DDT 18 per cent. E.C. at one fl. oz. per gal., endrin 20 per cent. E.C. at 0·5 fl. oz. per gal. or parathion 46 per cent. E.C. at 2 ml. per gal. at weekly intervals up to the time of flowering was very effective in controlling M. phaseoli.

The efficient control of the pest obtained with pre-sowing treatment of soil or seed suggests that the insecticides concerned may have been acting systemically. Laboratory studies on the life-cycle of the pest in plants derived from treated and untreated seed show that endrin (which was the only insecticide studied in detail in this way) has a larvicidal effect when used as a pre-sowing treatment.

Four geographical strains of Ceratitis capitata (Wiedemann) were subjected as third-instar larvae to mass selection with dieldrin. Two strains, SOUTH and COSRIC, responded well but continued to show substantial heterogeneity in tolerance to the insecticide after 21 and 25 generations of selection, respectively. The technique was altered to single family sib selection, resulting in the isolation from the SOUTH strain of a dieldrinresistant strain (73) showing a more homogeneous response to the insecticide. By the same technique, a dieldrin susceptible strain (72/3) was isolated from the COSRIC strain. A decline in resistance was observed in the 73 strain between generations three and four, but the level subsequently increased again, without selection, reaching 68-fold in generation seven. It remained high for the next two years. No significant change was observed in susceptibility to dieldrin of strain 72/3; it remained highly susceptible. Resistance to solutions of technical dieldrin (96%) was shown to be mainly under the control of a single major autosomal gene, intermediate in dominance but with a modifying effect of the genetic background on the expression of the resistance gene. The resistance heterozygotes, segregating in backcrosses to susceptible individuals, were shown to be more resistant than expected, while in backcrosses to resistant ones they were more susceptible. A dose of 11 p.p.m. dieldrin was found to discriminate almost completely between heterozygous and homozygous-susceptible individuals among backcross progeny. In tests using a purer form of the insecticide (99·7%), a similar pattern of resistance was observed. The implications for genetic sexing in C. capitata are discussed.

Experiment showed that all developmental stages of Lacemophloeus minutus (Ol.) can survive exposure to a temperature of + 2°C. for a limited period which varies with the instar.

The egg was more susceptible to such exposure than any other stage, followed by the first, second and third larval instars and the adult, which did not differ significantly from each other, and then by the fourth-instar larva and pupa which can also be grouped together.

The adult male proved 1·21 times more susceptible than the female to the effects of exposure.

Atmospheric humidity did not influence the mortality of eggs or adults. Previous starvation did not affect the mortality of adults subsequently exposed to + 2°C.

A review of the available information concerning gall midges as endoparasites shows that only three species in two genera have been described.

Endaphis perfidus Kieffer is a parasite of apterous Drepanosiphum platanoides (Schr.) (Aphididae) in Lorraine and England. Although on several occasions larvae of Endaphis sp. have been found in England, the Netherlands and Germany parasitising other Aphids, practically no information additional to that supplied by Kieffer has beeen published. In only one instance besides E. perfidus has the adult midge been reared and figured, i.e., Endaphis (cf. perfidus Kieffer) in Macrosiphum jaceae (L.) on Carduus in Germany.

Endopsylla agilis de Meijere is a parasite of winges Psylla foersteri Flor (Psyllidae) in the Netherlands. The bionomics of what is almost certainly the same species, parasitising P. mali race peregrina Foerst. on hawthorn (also P. pyricola Foerst. and P. melanoneura Foerst.) and P. mali (Schmidb.) on apple, respectively, have been studied in Scotland and Germany.

Endopsylla endogena (Kieffer) was found parasitising the larva of Stephanitis pyri (F.) (Tingidae) in Portugal but has not been recorded again.

A fourth species, Pseudendaphis maculans, gen. et sp. n., that parasitises various Aphids in Trinidad, has now been described.

Indications are given of the whereabouts of any existing types or other specimens of all the known endoparasitic gall midges.

Laboratory nests of the leaf-cutting ant Atta sexdens rubropilosa Forel fed daily with leaves of Ricinus communis showed a gradual decrease in fungal garden volume, a higher ant mortality rate, and fungal garden extinction after 6 weeks. The mean oxygen consumption rate of these ants was higher than that of control ants collected from nests fed with leaves of Eucalyptus alba (Myrtaceae) suggesting one or more components of the leaves of R. communis had a direct physiological effect on the ants, in addition to inhibiting fungal garden growth.

Daily light trap catches of Scotinophara coarctata (Thunberg) were analysed from mid-September 1986 to December 1990 and the physiological status of the trapped adults was examined. The catch size fluctuated synchronously with the lunar phase; large catches occurred around the full moon period and very few adults were trapped around the new moon period. Seasonally, the catches were large from January to March and from July to September, while they were small from May to June and October to November. The seasonal fluctuations of the catches seemed to be related to the growth stages of the rice plants on which the adults multiplied. The sex ratio of trapped adults was biased toward males, unlike that of the cage-reared insects which was 1:1. Most of the trapped females showed undeveloped ovaries and some of these females appeared to have oviposited previously. Light-attracted adults showed a considerable tolerance to starvation and survived for 20–30 days when they were given water, but for only two days in the absence of water. When the light-attracted females were supplied with food, their ovaries developed rapidly and females with mature eggs were produced after nine days. When the starvation period was prolonged, the ovaries remained immature and the fat bodies reduced in size. The nocturnal take-off of the adults was not triggered simply by the full moon illumination. Adult eclosion did not synchronize with the moon cycle.

Simulium (Phoretomyia) dukei sp.n., an occasional man-biter, is described and its systematic position discussed. Its larvae and pupae are associated with the prawn Atya africana Bouvier which is the only known host of phoretic Simuliids apart from river-crabs and mayfly nymphs. Four other phoretic species of Simulium are known in West Cameroon, and descriptions of two of them, S. berneri Freeman and S. ovazzae Grenier & Mouchet, are amplified.

A study was carried out to investigate the behavioural components of resistance in the Standlake strain of Musca domestica Linnaeus. The flies were collected from a poultry unit where azamethiphos spray-on-bait (Alfacron), had been regularly used to control the fly population. A no-choice laboratory cage test was used to observe the responses of the Standlake resistant strain to baits and compare it with two other strains namely, Sparsholt resistant and Cooper susceptible. The baits used were, Alfacron, sugar and analytical grade azamethiphos, sugar alone, and a blank target as control. Only female flies were used, each strain was exposed separately to each bait over a 50 minute period and the responses were recorded with a datalogger. The responses (per fly) recorded during each test period were: the number of visits to a bait; the time spent on a bait; the number of feeds and time spent feeding on the bait defined as the number of proboscis contacts and the length of time of proboscis contact with the bait. Knockdown of flies was recorded at the end of each test. All strains showed differences in their responses to baits. The Standlake strain showed the greatest difference to responses to Alfacron, with inhibition of proboscis extension when flies landed on the bait and a lower proboscis contact when extended, resulting in fewer flies being knocked down by Alfacron than by the sugar and azamethiphos bait. This suggested that inhibition of feeding on the Alfacron bait by the Standlake strain was caused by formulation components or contaminants and not the active insecticide ingredient, azamethiphos.

Seedbank control has been the cornerstone of agricultural management practices. Regulating weeds by using their predators, as a weed control strategy, may be a prerequisite of decreasing herbicide use, and has thus attracted much research investigating the possible contribution of both vertebrates and invertebrates as weed seed predators. Carabid beetles are considered as one of the most important invertebrate seed predators in agroecosystems. We aimed at investigating carabid beetle preferences to a single prey type, seeds of Viola arvensis. We measured the consumption of seeds in 28 species of carabid beetles, under controlled experimental conditions. Two main tribes are identified in tested species, Harpalini with 12 species and Pterostichini with ten species. We found no relationships between species body mass and Viola’s seed consumption, nor with the ratio between mandible length and labrum width (ML/LW). However, trends became significant with the ratio ML/LW when restricting these analyses to species that ate at least five seeds. In addition, we detected a positive and significant relationship between consumption rate and occurrence in trapping sessions over the last 3 years. These results are in favor of weed seeds control by carabids. Clear limits of this study are the use of a single seed species and under control conditions. This experimentation calls for additional studies to check for consistencies in consumption against seed species.

Tribolium castaneum Herbst 1797 (Coleoptera: Tenebrionidae), an important pest of stored grains and byproducts, is naturally infected by Gregarina cuneata Stein 1848 (Apicomplexa: Gregarinidae). Changes in the life cycle of insects caused by the parasite development in the midgut were studied. Trophozoites, gamonts (solitary and associated), and gametocysts were present in the midgut of the insects. In young trophozoites, the apical region differentiated into an epimerite that firmly attached the parasite to the host epithelial cells. With maturation, trophozoites developed in gamonts that were associated with the initiation of sexual reproduction in the cell cycle, culminating in the formation of the spherical gametocyst. Morpho-functional analyses indicated that gregarines absorb nutrients from infected cells and can occlude the midgut as they develop. Consequently, nutritional depletion may interfere with the host's physiology, causing decreased growth, delayed development, and high mortality rates of the parasitized insects. These results suggest G. cuneata could be an important biological agent for controlling T. castaneum in integrated pest management programs.

The Senegalese grasshopper, Oedaleus senegalensis (Krauss) (Orthoptera: Acrididae), is a major grasshopper pest of subsistence crops in the West African Sahel. In northern Mali, O. senegalensis spends the dry season in the egg stage in the soil and eclosion is triggered by the first rains which usually occur in May and June. Satellite imagery potentially enables rainfall, and hense O. senegalensis eclosion, to be monitored over much wider areas than those possible for ground-based observers. In 1990 and 1991, rain-gauge networks were set up at Mourdiah, northern Mali, and for each storm event, rainfall and Meteosat infra-red data were collected. The coldest convection clouds (< -70°C) produced rain 93.1% (n = 15) of the time, whereas warmer cloud (>- 10°C) produced rain only once (n = 61). The relationship between minimum cloud temperature and log transformed rainfall data was negative and highly significant (P < 0.0005). The maximum rain-gauge separation for reliable point measurements of rainfall was 8 km. Simulated rainfall experiments showed that O. senegalensis eclosion is influenced both by soil type and by the quantity of water added to the soil. A grasshopper survey after the first rain in 1994 showed that 8 mm of rain was sufficient to cause eclosion 9 days later. The implications of these results for improved O. senegalensis control are discussed.

The cotton bollworm, Helicoverpa armigera, is a major pest of many agricultural crops in several countries, including Australia. Transgenic cotton, expressing a single Bt toxin, was first used in the 1990s to control H. armigera and other lepidopteran pests. Landscape scale or greater pest suppression has been reported in some countries using this technology. However, a long-term, broad-scale pheromone trapping program for H. armigera in a mixed cropping region in eastern Australia caught more moths during the deployment of single Bt toxin cotton (Ingard®) (1996–2004) than in previous years. This response can be attributed, at least in part, to (1) a precautionary cap (30% of total cotton grown, by area) being applied to Ingard® to restrict the development of Bt resistance in the pest, and (2) during the Ingard® era, cotton production greatly increased (as did that of another host plant, sorghum) and H. armigera (in particular the 3rd and older generations) responded in concert with this increase in host plant availability. However, with the replacement of Ingard® with Bollgard II® cotton (containing two different Bt toxins) in 2005, and recovery of the cotton industry from prevailing drought, H. armigera failed to track increased host-plant supply and moth numbers decreased. Greater toxicity of the two gene product, introduction of no cap on Bt cotton proportion, and an increase in natural enemy abundance are suggested as the most likely mechanisms responsible for the suppression observed.

The sparetus-group of Entedon is revised. Six species are recognized for the group, including one new species, E. lucasi Gumovsky sp. n., which is described from Algeria. All species are either diagnosed or described, and illustrated, and new distribution records are provided. An illustrated dichotomous key to all species of the group is given. Biology of two species, E. thomsonianus Erdös and E. sparetus Walker, is studied in detail: both species proved to be egg-larval parasitoids of stem-boring weevils, Lixus cardui Olivier on the scotch thistle Onopordum acanthium and Gymnetron asellus (Gravenhorst) on mullein Verbascum sp., respectively. The morphology of larval stages and peculiarities of parasitoid–host relationships are described. Possible benefits of egg-larval parasitism for Entedon species are discussed.

Sticky traps baited with (Funemone cis-8-dodecenyl acetate or (Codlemone trans-8,trans-10 dodecadien-1-ol) were operated in plum orchards in Cambridgeshire, England, from 1974 to 1976. In addition to large numbers of the target species Cydia funebrana (Treitschke), males of 24 other tortricids were captured. These included species of Cnephasia, Celypha, Epiblema, Pammene and Cydia. As an aid to the correct identification and interpretation of trap catches, details are given of the more important species attracted by the pheromone baits.

(1) An adhesive made from 3 or 4 parts (according to the temperature) of the coagulated latex of Carpodinus hirsuta and I part of either shea butter (from Butyrospermum parkii) or palm oil (from Elaeis guineënsis) was found to be very effective against both house-flies in kitchens and Stomoxys spp. in pig pens.

(2) In kitchens, wires (diameter 4 mm.) were treated with the adhesive and suspended over the table on which food was prepared. The wires should be renewed every three or four days when flies are abundant and once a week when the infestation is light.

(3) At Ibadan in 1943, house-flies were abundant from early March to late July; the maximum house-fly infestation of both kitchens and pig pens occurred during the second week of May. The upward trend in adult incidence first became evident in mid-February of both 1943 and 1944 and appeared to be correlated with a rise in temperature at that time.

(4) Ten wires treated with adhesive were suspended under the eaves of each pig pen. Each pen consisted of a covered pen and an open yard divided by a half-wall; a screen made of oil palm fronds was erected above the half-wall with the object of making the innerpen sufficiently dark to deter flies from entering it. About half a million flies (about 27·5 per cent. Stomoxys spp.) were trapped in12 pens in a period of 112 weeks.

(5) Stomoxys spp. (principally S. nigra, Macq.) were abundant between early June and mid-August in 1943 and between early June and late November in 1944. In 1943 there was a short dry season between 25th July and 12th September, whilst in 1944 there was no break in the rains. There is a marked correlation between rainfall and the incidence of S. nigra. Heavy rainfall soaks straw round the stock-yards, heaps of weeds, etc., which decompose and provide suitable media for larval development.

The following paper deals with collections of sandflies made by Professor P. A. Buxton in Nigeria, and by the late Professor J. G. Thomson in Nyasaland, and collections sent by Sir Guy Marshall, Director of the Imperial Institute of Entomology, and by Dr. F. W. Edwards of the British Museum (Nat. Hist.), for identification.

Seven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.

In this paper are described the early stages of a few more West African mosquitos. All the specimens were collected in the Gold Coast, and most of them at Accra or in the neighbourhood of that town. In drawing up descriptions of larvae we have followed the usual plan, but in the case of the setae on the head have given, when necessary, the terms employed by W. D. Lang in his admirable handbook of British Mosquitos. In drawing up descriptions of pupae we have used the terms (and lettering) suggested by one of us in his account of the chaetotaxy of the pupa of Stegomyia fasciata (Aëdes argenteus).* We have once more to express our indebtedness to Dr. G. A. K. Marshall, of the Imperial Bureau of Entomology, and to Mr. F. W. Edwards, of the British Museum, for help and advice and for the identification of species, and to Mr. A. J. Engel Terzi for his skilful execution of the figures.

An effort was made to determine the best conditions to achieve maximum saturation and persistence of small droplet insecticide (5-200 microns droplet diameter) within a type of African woodland. The problem is entirely one of atmospheric turbulence within the woodland. No attempt was made, or is likely to be fruitful, to introduce a detailed or mathematical argument. The relevant factors pertaining to atmospheric turbulence were observed and in some cases were directly compared with simultaneous observations made in the open.

The absence of zero wind speeds, considerations of changing lapse rates, bi-directional wind vane records, and visual observations of smoke, all combine to suggest that when conditions of calm or light winds exist in the free air, there is, under moderately dense woodland canopies, an almost continuous and slow transfer of air between the canopy and the ground, these movements tending towards laminar or sheet flows. With stronger winds, eddying about the trees swamps these gentle movements and air motion becomes erratic and turbulent, although such turbulence is less the denser the canopy. During the daytime there is notable horizontal movement of air towards clearings where convection is at a maximum.