The repellent ‘Simno’, which is made in Ghana from edible plant products, was tested in two forms as base-oil and a cream. Biting catches were made by bait subjects with one leg only smeared with a measured amount of ‘Simno’. The catches from each leg were then compared. The base-oil was only tested against Simulium damnosum s.l. It was found to be 100% effective for over 10 hr even after 2 years storage. The repellent cream worked well against a biting midge and various mosquitoes as well as S. damnosum s.l, but was seldom completely effective and the potency varied between samples. Nevertheless, one sample retained its full potency after 2 years storage. ‘Simno’ repellent is convenient to use (especially the cream) and is well accepted by the local people. The active ingredients of'Simno’ need to be identified.

At room temperature (diurnal range 23–28°C), Sarcophaga haemorrhoidalis (Fallen) developed from egg to adult in approx. 32 days. Survival ( ± SE%) was generally high (76.63 ± 5.67 for the egg, 80.69 ± 3.20 for the larval and 89.83 ± 3.80 for the pupal stages). Adults emerged over a 4-day period between 07.00 and 13.00 hr local time, with daily peak emergence occurring between 07.00 and 10.00 hr. Their immediate post-emergence period was characterized by a highly active and mobile phase lasting 10–15 min followed by an immobile phase lasting about 1.5 hr. Copulation commenced 4.35 ± 0.43 days after adults emerged and was not preceded by elaborate courtship. After a pre-oviposition period of 12.96 ± 0.47 days, females deposited eggs in batches (1.57 ± 0.23 egg-batches/female) each containing a mean of about 37 ± 4 eggs. Fecundity was 52 ± 6 eggs/female during a mean adult life span of 18.68 ± 1.76 days. Although the foregoing life history parameters are strongly suggestive of K-selected ecological strategy, S. haemorrhoidalis may in fact be adopting an opportunistic r−selected ecological strategy since it habitually breeds in unstable environments.

Eight papers were presented on topics ranging from the dissemination of drug resistance in Africa; the application of new antimalarial compounds; the basic biology of the malarial parasite; and methods for in vitro culture and its analysis, to the interaction of the malarial parasite with the infected host with particular reference to host genetic factors responsible for parasite survival.

The effect of temperature and relative humidity on mating and commencement of oviposition in Plodia interpunctella (Hubner) was studied in the laboratory. Mating was most successful at 20 and 30°C and was less so at temperatures of 15 and 35°C. Increased relative humidity appeared to have favoured mating at higher temperatures investigated which were 30 and 35°C.

The onset time for mating was higher at 30 and 35°C than at 15 and 20°C. Mating started earlier at the lower temperatures than at higher temperatures. The mean duration of mating was higher at 15 and 20°C than at 30 and 35°C at which high relative humidity favoured increase in mating time.

At 20 and 30°C oviposition started within the first 2 days of mating whereas at 15°C oviposition started about 8 days after mating. At 35°C oviposition commenced within 4 days. Low relative humidity caused early commencement of oviposition at 15 and 35°C.

Recent studies have greatly clarified the epidemiological situation of leishmaniases in the Middle East. Notable contributions have come from the accurate identification of the parasites responsible for the different diseases, correlation of disease prevalence with bioclimatic zones, and the incrimination of reservoir hosts.

Sufficient information now exists in many areas for the prediction of outbreaks and the establishment of pilot control schemes in development projects. However, much remains to be learned on the significance of cryptic infections and on the population dynamics of reservoir hosts.

Distribution patterns of the critical stages of the major pod borer, Adisura atkinsoni (Moore) of field bean were studied at Bangalore, India. Eggs of A. atkinsoni and the pods damaged by its caterpillar followed negative binomial distribution. Eggs were distributed mostly on tender pods and those on tender pods (<0.5 cm wide) were highly correlated with total number of eggs laid on the inflorescence. Flat bored pods of 0.6–1.5 cm width were highly correlated with total number of bored pods per inflorescence. Compared with matured bored pods, flat pods also had more borers inside. 69.23% of the matured bored pods were without borers. Hence it is suggested that the eggs on tender pods and borer damage on flat pods, should both be observed before control measures are initiated.

The structure of hildecarpin, an insect antifeedant 6a-hydroxypterocarpan isolated from the roots of Tephrosia hildebrandtii has been confirmed by a combination of degradation reactions, NMR and mass spectra. Hildecarpin has been dehydrated to the corresponding pterocarpene 3-hydroxy-2-methoxy-8,9-methylenedioxypterocarpene. Hydrogenation and hydrogenolysis of the pterocarpene has afforded the isoflavan 2′, 7-dihydroxy-6-methoxy-4′,5′-methylenedioxyisoflavan, acetylation of which has led to 2′, 7-diacet6xy-6-methoxy-4′,5′-methylenedioxyisoflavan. The NMR and mass spectra of the degradation products confirm the structure previously assigned to hildecarpin.

Investigations on sandfly breeding sites in Marigat, Baringo District, in Kenya were carried out using a soil incubation technique. Soil samples from natural resting sites were collected, incubated and observed daily for emerging adult phlebotomine sandflies. This technique proved to be the best in the recovery of phlebotomine sandflies from known resting sites. Ten sandfly species were recovered from soil collected from animal burrows and termite hills.

We have tried to demonstrate in this paper that visceral and cutaneous leishmaniasis are a great public health problem in Brazil. In relation to visceral leishmaniasis, the recognition of new foci denotes the increasing spread of endemic areas, but the areas of highest importance are located mainly at the northeastern region. It calls attention to its suburban character in cities like São Luis, Teresina and Rio de Janeiro. L. longipalpis is the only vector known for the disease in domiciliary environment. The dog constitutes the main source for L.d. chagasi, while canids such as Dusicyon vetulus and Cerdocyon thous have epidemiological roles. Other vectors for this parasite remain yet as unknown in the enzootic and sylvatic cycles.

Cutaneous leishmaniasis have a distribution in almost all the States of Brazil and, at least, two epidemiological patterns exist. The first, corresponds to the classic form of man entering in contact with the agent in virgin forests, like the Amazonian forest and so, there is a permanent risk for epidemics. The second, refers to the occurrence of this disease in areas after forest devastation as in the State of São Paulo and in other southeastern States. There are three nosological entities for the cutaneous leishmaniasis in Brazil, their agents being L.m. amazonensis, L. guyanensis and L.b. braziliensis. Five sandfly species have been incriminated as the main vectors in the transmission of the disease in different localities. They are P. flaviscutellatus, P. umbratilis, P. welcomei, P. whitmani and P. intermedius. As for the main natural reservoir of cutaneous leishmaniasis, it remains unknown the one relative to L.b. braziliensis.

Studies of outer chorionic sculpturing of eggs of four species of sandflies were carried out by the use of scanning electron microscope. Two species, P. martini and S. garnhami, which utilize similar resting sites, termite hill ventilation shafts, had similar chorionic sculpturing, while two other species (S. bedfordi and S. kirki) which use several resting sites, i.e. rock crevices, tree holes and termite ventilation shafts, had chorionic sculpturings which were dissimilar.

The human body louse aggregates on filter paper impregnated with an aqueous extract of louse faeces. Chemical analysis of the faeces revealed the presence of haemoglobin, xanthine, hypoxanthine, uric acid and ammonium salts. Of all these compounds, only ammonium salts caused marked aggregation of lice. Excretory products of other insects and ticks also failed to induce aggregation. Total faecal material was more attractive than ammonium, and led to greater aggregation of females than of males. Antennectomized lice reacted neither to faeces extract nor to ammonium carbonate solution.

Between 1979 and 1982, H. hampei spread itself from a small area in the lowlands of central Jamaica, to the entire coffee growing region (alt. 15–1603 m) of the island. The levels of infestations in the 390 farms surveyed ranged from less than 5–100%; in plains it was about 45% but only about 3.4% at altitudes of over 1000 m. On a parish basis the infestation ranged from 2.8 to 19.17% (mean 9.45%) in June 1982, before the spraying with thiodan EC35 began.

In November 1982, 8 weeks after the last spray of the three-spray cycle, the infestation levels ranged between 1 and 20.21% (mean 9.56%). In fact, it had increased from about 6.7% in 1979 to 9.56% in 1982, despite the multi-million dollar spraying programme over 4 years. The shortcomings of the chemical control strategy are discussed and an integrated approach involving chemical and cultural practices is advocated.

No insect parasite or predator of H. hampei were found in Jamaica; the fungus Beauvaria bassiana was however, found to have inflicted 6–40% mortality in the adult borer.

Laboratory examination of blood smears from water buffaloes in an area of high fly challenge indicated an infection rate of 51.11 % caused by both Trypanosoma congolense and T. vivax. A similar study in cattle raised in a low fly challenge area showed an infection rate of 22.73% caused by T. congolense only. Diminazene aceturate administered as a single dose at 3.5 mg/kg body weight cured the infection in cattle, while a similar dose at 7 mg/kg body weight failed to cure the water buffaloes. Cattle were further protected by a single dose of isometamidium chloride administered at 0.5 mg/kg body weight for 6 weeks of this study. On the other hand, isometamidium chloride administered at 1 mg/kg body weight cured transiently 90% of the infected water buffaloes and 10% persisted with a T. congolense infection. It was concluded that the lower dose rates approved by the manufacturers for the two trypanocides treated adequately infected cattle in a low challenge area, but such results were not achieved with the higher dose rates for infected water buffaloes in a high fly challenge area.

Professor Canning opened the satellite meeting by reporting that Professor Erich Scholtyseck, who had in part organized the session had died. She expressed the feeling of the meeting that, as a distinguished scientist and gracious personality, he would be sadly missed on the international scene.

Three of the speakers dealt respectively with the systematics of Perkinsus spp. and Spiromonas spp, the eimeriine coccidia and the piroplasms. The fourth speaker concentrated on the role that some of the newer technologies could play in research on taxonomy of Protozoa.

The corn earworm damage to seven maize cultivars TZB, TZPB, WYI, 096EP6, Farz 25, ‘Kewesoke’ and Local White, was assessed during the early and late cropping seasons of 1980 and 1981 at Ikenne and Ilora located in the rain-forest and derived savanna zones, respectively. The effectiveness of dimethoate and permethrin in controlling the earworms was evaluated. All the cultivars appeared susceptible to earworm infestation in the two ecological zones. Infestation was consistently and significantly higher in the early season and also in the rain-forest zone. It ranged from 71.5 to 86% in the early and from 28 to 36.8% in the late seasons, respectively, at Ikenne. At Ilora, infestation ranged from 53 to 82% and from 20 to 75% in the early and late seasons, respectively. Mussidia nigrivenella and Heliolhis armigera were the dominant species recorded damaging the grains.

Earworm infestation was significantly lower on plots treated wtih three applications of 0.05 and 0.1% a.i. permethrin at weekly intervals than on plots that received the same dosages and sprays of dimethoate and the control. Maize yields were significantly higher on permethrin-treated plots. The lower dosage of permethrin is recommended to reduce chemical residue on maize grains.

The prepupal stage of Spodoptera littoralis was affected by Bacillus thuringiensis kurstaki HD-1 (Dipel) at high concentration (5%), when sprayed or kept in soil treated with the pathogen. The emerged moths showed a short longevity associated with low egg production and low fertility. Increase in malformed individuals was observed. Treatment of the pupae of S. littoralis with B. thuringiensis during different ages showed an increased effect when treatment was applied, immediately after pupation.

Bacillus thuringiensis H-14 (Alex), originally isolated from moribund and dead larvae of the casuarina stem borer, Stromatium fulvum, was tested in the laboratory against the second and fourth-instar larvae of both mosquito species, Aedes aegypti and Culex pipiens. The pathogenicity of this bacillus was established when both insects were found to be susceptible to infection over the whole range of test concentrations (0.005–0.35 mg/1). However, A. aegypti showed a higher degree of susceptibility to B. thuringiensis H-14 (Alex) than C. pipiens. A mortality of 100% was achieved within 24 hr with concentrations of 0.09 and 0.25 mg/1 for second- and fourth-instar larvae of A. aegypti, respectively. Also, younger larvae of both test mosquito strains were more susceptible than mature ones.

Malaria, African trypanosomiasis, theileriosis, babesiosis and coccidiosis are of great public health and/or economic importance in eastern Africa. Leishmaniasis is an increasing problem in this area and other protozoal diseases which are found among human and/or livestock populations include toxoplasmosis, trichomoniasis, amoebiasis, giardiasis, sarcocystosis, Balantidium coli infection and histomoniasis.

Control of the vector-borne parasitic protozoan diseases has been based mainly on the use of pesticides with their attendant, adverse effects on the environment.

The paper describes the public health and economic problems posed by the main protozoan diseases in eastern Africa and discusses their control, stressing the importance of environmental considerations when planning control measures. Further, a consideration of the public health impact of these diseases when drawing up, and during implementation of, major agricultural, hydro-electric or irrigation schemes, is emphasized. The possible effects of control measures on the social and economical welfare of local communities is highlighted.

Arthropods feeding on horses in the stables situated in three towns in south-western Nigeria were investigated. Flies were caught on horses with trap-net while ticks and lice were picked from them with forceps. Stomoxys, Tabanus, Glossina and Hippobosca species were the main blood-sucking flies caught, while myiasis flies and Musca species were also found. Furthermore, three genera of ticks, Boophilus, Hyalomma and Rhipicephalus and two species of lice, Haematopinus equi and Damalina equi, were recorded. The veterinary importance of the association of these arthropods with horses is discussed.

Investigations into the vectorial capacity of wild caught Phlebotomus pedifer by feeding them on volunteer patients were carried out inside one of the caves of Mt Elgon. Female P. pedifer were fed on lesions of cutaneous leishmaniasis patients to determine the route of infection and infection rates in the flies and hence their vectorial capacity. The flies were kept for periods of 3–8 and 9–13 days before dissections were carried out. The results indicate that the longer period (9–13 days) yielded a higher infection rate. All parasite isolations from flies which were injected subcutaneously caused cutaneous lesions in the nose of the experimental hamsters. All infections were concentrated in the anterior stations of the gut of the experimental sandfly species P. pedifer.