Female ticks of Ornithodoros porcinus porcinus undergo a series of adult moults when fed on blood containing ecdysteroids. The supermoulted ticks are bigger, ingest larger blood meals and lay more eggs than normal females. However, their rate of conversion of blood into eggs and their oxygen uptake are reduced in comparison to normal ticks. Their ability to resorb the rehydrated salt crystals is impaired. They are unable to shed the cuticle of the Géne's organ area leaving the organ constantly protruding, thus making the ticks vulnerable to dehydration. These factors are probably responsible for the very high mortality and the failure of most of the ticks to moult at the third supermoulting cycle.

Breeding biology of oil palm weevil, Temnoschoita quadrimaculata Gly., was studied. Females lay small, whitish and cylindrical eggs singly in cut wounds made on the fronds and trunk of oil palm, Elaeis guineensis Jacq. The larvae were found to feed voraciously in the fresh and dead tissues of the palm fronds and trunk. The weevil has six overlapping generations. Unmated females were observed to have longer pre-oviposition period, laid fewer eggs and lived longer than the mated ones. Durations of the immature stages of the weevil are studied. Natural enemies and alternate host plants of the pest are given.

Twenty-one insecticides were tested for acute toxicity by surface film contact method against the grasshopper, Zonocerus variegatus (L.) in the laboratory. Decamethrin, cypermethrin, lindane o, o-diethyl(p-methyl sulfinyl) p′-phosphorothioate, and dieldrin were highly potent. Moderately potent insecticides were propoxur, bioallethrin, telodrin, isodrin, heptachlor and rotenone. A toxic symptom common to all potent insecticides in the female was the opening and closing of ovipositor valves which remained wide open at death. Five insecticides—dieldrin, telodrin, p, p′-DDT, chlorobenzilate, DMC and chlordimeform induced cannibalism among the treated females.

Coelomomyces indicus was reisolated from six larvae of Anopheles gambiae in Uganda. A crustacean copepod Cyclops sp. was found to be infected (63%). This indicated that the copepod could be an intermediate host for the fungus. All the four instars were highly susceptible to C. indicus but fourth instar Aedes aegypti was fairly susceptible (94.2%), while second instar An. gambiae (100%) and second instar C. fatigans (100%) were the most susceptible.

Laboratory tests were conducted to compare reproductive capacity and longevity of An. gambiae, C. fatigans and Ae. aegypti when infections of C. indicus were induced in each of the different larval instars. Infections of C. indicus sharply reduced the reproductive capacity and longevity of An. gambiae, C. fatigans and Ae. aegypti, regardless of the instar that were exposed and became infected. The reductions were highest when first and second instars were exposed. The tests indicated that introduction of C. indicus into laboratory populations of An. gambiae, C. fatigans and Ae. aegypti consisting of mixed larval instars, could significantly reduce the number and fertility of eggs and thus result in an average reduction of about 65.4% for An. gambiae, about 46.7% for C. fatigans and 58.7% for Ae. aegypti of the F1 progeny from those females that became infected. The importance of these results in biological control is discussed.

Life history components, especially those of the adult stage, were investigated in Aedes aegypti and Culex quinquefasciatus in the laboratory. Males of Cx. quinquefasciatus had a greater expectation of life at adult eclosion than males of Ae. aegypti. There was no statistically significant difference in the means of life expectancy for females of Ae. aegypti versus those of Cx. quinquefasciatus. In both species, males had a shorter life than females. The two species exhibited considerable heterogeneity for reproductive characters. Females reproducing for the first time were younger in Cx. quinquefasciatus than in Ae. aegypti. Net reproductive rate and the per capita rate of increase were greater in the former than in the latter species. Cx. quinquefasciatus had a shorter generation time than Ae. aegypti. The data reported here are inconsistent to varying degrees when compared with data gathered by other workers from the same species. The results are discussed with reference to the theoretical constructs of the life history theory.

The effects of various exposure to irradiation from cesium 137 in nitrogen and air on survival and fecundity of Glossina palpalis palpalis were compared. With doses from 3 to 21 krad in nitrogen atmosphere, male fertility was inversely correlated with dose, above 15 krad male survival was inversely correlated with dose. All males subjected to either 21 krad in nitrogen or 15 krad in air were sterilized. Females appeared to be more sensitive to gamma-irradiation than males; a dose of 6 krad in nitrogen resulted in 100% sterility and arrested further development of the ovaries after the ovulation of follicles A1 and C1. In males, this dose caused 70.3% sterility. Approximately 97 and 98% sterility were obtained when males were treated with 15 krad in nitrogen and 12 krad in air respectively. No fly emerged from irradiated puparia younger than 15 days. Irradiation of 15 or 20 days old puparia killed the insect either before or shortly after eclosion, whereas the normal patterns of emergence, survival and reproduction were observed from puparia that were irradiated when 25 days old or older.

Over the last decade, public authorities from all parts of the world have expressed their growing concern about leishmaniasis being a serious threat to health. This increased awareness occurred partly as a result of serious outbreaks which were reported, such as for instance, the one in Bihar, India and earlier in Kenya. Several health services in South America have indicated increases in both the mucocutaneous and cutaneous disease. It is difficult to say to what extent these observations reflect true increases or perhaps indicate more successful efforts in detecting new patients.

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.

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.

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.

The breeding sites and biology of Phlebotomus pedifer was investigated in the caves of the old focus of cutaneous leishmaniasis in Mt Elgon, Bungoma District, Kenya. Phlebotomus pedifer was found to rest mainly in the poorly lighted areas of the caves, on the roof, the floor of caves under objects, and in cracks and crevices inside the caves. The flies were also found in abundance in cracks and crevices outside the caves where hyraxes were found to rest. Immature stages of P. pedifer were recovered from wet areas of the floor of the caves. The biology of this species was investigated and the mean duration from egg to adult was 37 days.

The vectors of Leishmania major were investigated in Marigat, Baringo District, Kenya, a focus of both visceral and dermal leishmaniases. These studies resulted in the discovery of the resting sites of Phlebotomus duboscqi, a known vector of L. major, and of alternate principal resting sites of Phlebotomus martini, a known vector of visceral leishmaniasis. Furthermore, Sergentomyia ingrami was incriminated as a possible vector of L. major among susceptible rodents inside burrows. Trapping methods which have resulted in the discovery of the resting sites of these phlebotomine sandflies are presented in this paper.

An investigation was carried out around animal burrows in Marigat, Baringo District (Kenya) for 6 months to observe host attraction or host preference of phlebotomine sandflies. Six different kinds of caged animals from groups of Rodentia, Aves, Reptilia, Carnivora and Bovis were used. The host preference of Phlebotomus duboscqi, P. martini and Sergentomyia ingrami were distinctive. Most of the Sergentomyia species preferred feeding on reptilian hosts as is indicated in the blood meal analysis. Among the species were opportunistic feeders on hosts which appeared not to be favoured hosts.

Three types of human leishmaniases are known to occur in Kenya: visceral leishmaniasis, caused by Leishmania donovani, and cutaneous leishmaniasis caused by L. aethiopica and L. major. Visceral leishmaniasis is the most important of the three in eastern Africa, not only because it is fatal but also because several epidemics have occurred periodically since the disease appeared in the country about 40 years ago resulting in many deaths. L. aethiopica and L. major are chiefly zoonotic and people contract the disease when they wander into areas containing animal reservoirs and infected vectors. Control measures were undertaken against vectors and reservoirs during an epidemic outbreak of kala-azar in Machakos District.

The paper reviews advances in our understanding of the vectorial capacity and vector–parasite relationship in Kenyan sandflies since the early 1900s (when sandflies were first reported in Kenya). Of the 38 species of sandflies known to occur in Kenya to date, three (Phlebotomus pedifer, P. martini and P. duboscqi) can naturally carry biochemically and serologically confirmed Leishmania (aethiopica, donovani and major, respectively) and 12 (Phlebotomus rhodhaini, Sergentomyia garnhami, S. squamipleuris, S. africanus, S. kirki, S. ingrami, S. antennatus, S. bedfordi, S. schwetzi, S. affinis, S. graingeri and S. clydei) carry various flagellates of biochemically or serologically unknown character.

Current research on naturally infected wild-caught sandflies indicates that L. aethiopica promastigotes have close association with structures resembling a peritrophic membrane and invade P. pedifer gut cells. Promastigotes invade the malpighian tubules of S. garnhami and S. antennatus.

Studies on laboratory-reared sandflies show that P. martini is susceptible to L. donovani amastigotes and that cultured promastigotes of L. donovani can survive in the guts of S. schwetzi, S. ingrami and S. adleri.

Experimental infection of sandflies with Leishmania is discussed and priorities for laboratory work set.

Identification and taxonomy of the genus Leishmania is considered in brief, drawing on existing review articles. A fully-referenced synopsis of clinical, epidemiological, biological, immunological and biochemical criteria and methods used for typing leishmanial parasites is given and discussed. Classical and modern approaches are compared. Leishmanial phylogeny, the value of numerical taxonomy and the possibility of sexual recombination in leishmanial organisms are also considered.

The systematics of phlebotomine sandflies have significantly advanced in the last two decades through the incorporation of a growing body of information on the biology of sandflies and the introduction of new techniques: chromosome analysis, enzyme electrophoresis, detailed morphological studies, laboratory rearing and colonization, and multivariate morphometrics. These techniques have been used mainly in the study of intra-specific variation of vector species. The rôle of sandfty systematics in the epidemiology of leishmaniasis is discussed.

This paper combines some of the results from three studies that explain the system by which the gut of Phlebotomus papatasi is maintained bacteria free. This system includes an antibacterial factor in the crop (diverticulum) and feeding behaviour which determines selective routing of meals. When feeding by piercing animal skin or plant tissue, in a ‘blood feeding’ mode, the uncontaminated meals of both sources enter the midgut directly. Free-solution sugar-meals which may contain contaminants, enter the crop where they mix with the antibacterial agent. Feeding on plants is also described.

The diagnosis of visceral leishmaniasis must be based upon a demonstration of the parasite in tissues of the patient. The best diagnostic test is a splenic aspirate, which is safe, highly sensitive and specific if the technique described in this paper is used and both smears and cultures of the aspirate are performed. Peripheral blood and nasal exudate have parasites in smears and/or cultures in 75 and 40% of Kenyan visceral leishmaniasis patients, respectively. Sodium stibogluconate (Pentostam) is the preferred treatment for visceral leishmaniasis. Recent Clinical Research Centre trials of different schedules of treatment with sodium stibogluconate are discussed. Currently, we recommend sodium stibogluconate, 20 mg/kg once daily for 30 days, for initial treatment. For patients who have not responded to initial treatment with sodium stibogluconate or have relapsed after initially responding to this treatment, we recommend sodium stibogluconate, 20 mg/kg once daily for 60 days. Further studies are now underway comparing the combination of allopurinol plus sodium stibogluconate versus sodium stibogluconate alone for unresponsive or relapsed patients.

The distribution of canine leishmaniasis and figures on infection frequency in countries bordering the Mediterranean Sea are given. The clinical picture and most common laboratory findings are reviewed. Leishmania infantum is the aetiological agent of both human and canine forms of visceral leishmaniasis. The proved or suspected vectors of L. infantum are listed and mention is made of wild animals (fox, rat) as possible primary reservoirs of the parasite. Finally, the methods of investigation and control of canine leishmaniasis are discussed.