D. J. Lewis

Proposals for a stable classification of the phlebotomine sandflies (Díptera: Psychodidae).

Abstract. A practical system of classification and nomenclature for the Phlebotomine sandflies of the world is suggested, in the light of a re‐examination of the early taxonomic literature and a critical appraisal of recent studies. A stable and simple classification of the sandflies as the subfamily Phlebotominae, family Psychodidae, is given, in which are recognized only five genera but a larger number of subgenera, species groups and lesser, informal, categories.

Onchocerca-Simulium complexes. I. Transmission of forest and Sudan-savanna strains of Onchocerca volvulus, from Cameroon, by Simulium damnosum from various West African bioclimatic zones.

(1966). Onchocerca-Simulium complexes. Annals of Tropical Medicine & Parasitology: Vol. 60, No. 3, pp. 318-336.

Parasites of British Honduras with special reference to leishmaniasis.

1. 1) Fifty cases of chicleros ulcer or bay sore are reported from British Honduras, and the epidemiology of the disease is discussed. Infection is strictly limited to people living inside the forest for prolonged periods. 2. 2) The causative organism, and its behaviour in animals, is described. Inoculation of a culture of a local strain into the spleen of hamsters resulted in a widespread systemic infection and produced by fatty degeneration of the RE cells. Akinetoplastic organisms developed in some of the subcutaneous lesions. At present the organism is best called a special “nosodeme” of L. brasiliensis. 3. 3) There is little doubt that bay sore in British Honduras is a zoonosis, though examination of the following animals gave negative results:—armadillos, pacas, wild rodents, opossums, dogs and a fox. 4. 4) Fourteen species of Phlebotomus were found in British Honduras, eight of which were taken on man, including P. cruciatus Coquillett, which is believed to transmit cutaneous leishmaniasis in Mexico, and two species closely related to P. whitmani Antunes and Coutinho, a vector in Brazil. Their habits are briefly described. No leptomonads were found in a small number dissected. 5. 5) It is suggested that “control measures” for leishmaniasis in British Honduras might be by the use of attenuated vaccine, and an attempt was made to immunize hamsters. 6. 6) Thirteen species of Simulium were found, of which two, S. quadrivittatum Loew and S. metallicum Bellardi, attack man in large numbers. The occurrence of human onchocerciasis in Guatemala raises the question of its possible spread into British Honduras, and this is discussed. 7. 7) Many other organisms are recorded or discussed, including new species of parasitic protozoa, microfilariae of the toucan, some mosquitoes, midges and other insects, and larval ticks.

Determination of parous rates in Phlebotomine sandflies with special reference to Amazonian species.

Previous work on Phlebotomines has shown that most parous flies in many species may be recognised by the dark residual secretion in the accessory glands; parity can be confirmed by inspection of ovarioles. In the present study 12 species of Lutzomyia were caught in forests near Belem, Brazil, mainly with rodent-baited oil-traps. Many females of the predominant species, L. flaviscutellata (Mangabeira), were parasitised by the protozoan Monocystis. Parous rates based on examination of ovaries were subject to an error of about 5% due to diminution or disappearance of follicular relics. Two successive dilatations of the tunica were seen in L. davisi (Root), suggesting that it had laid two batches of eggs. Biting rates by parous flies varied little during the night, and were somewhat less than those of nullipars. In eight species the dark-gland rate approximated to the parous rate as shown by the ovaries; a small error may have been due to discharge of all secretion, disappearance of follicular relics and premature activity of glands. In contrast to this concordant pattern, four species showed discordance, possibly due to autogeny. It seems advisable to omit oil-trapped blood-fed flies when estimating parous rates by examining glands. Monocystis may increase the dark-gland rate, but it is non-pathogenic or has little effect on life span, and does not hinder blood-sucking.

Onchocerca-Simulium complexes: II.—Variation in West African female Simulium damnosum

(1966). Onchocerca-Simulium complexes. Annals of Tropical Medicine & Parasitology: Vol. 60, No. 3, pp. 318-336.

The recognition of nulliparous and parous Anopheles gambiae by examining the ovarioles

Abstract Ovaries of Anopheles gambiae were dissected in normal saline containing detergent which served to drown the mosquitoes, swell the ovaries and facilitate dissection, and burst many cells of the ovarioles so that the tunica propria was clearly seen and indicated the shape of the funicles.Parous females were recognized by the presence, in some of their ovarioles, of the “funicle stump” composed of a second or later funicle terminating in a fragment of an old follicle.

Depth of penetration of vertebrate skin by phlebotomine sandflies (Diptera: Psychodidae).

The limited knowledge of penetration depth and its relation to Leishmania transmission is reviewed. Labrum length and maxillary dentition of a number of species of phlebotomines are compared. It appears that the labrum of Phlebotomus argentipes, the vector of kala-azar in eastern India, is only just long enough for obtaining a blood meal in normal human skin. More information on penetration depth is needed, and it might possibly be estimated from the length of the labium when it remains outside the skin and contracts. It would be necessary, however, to note the position of the labium which changes in relation to the labrum.

The Anopheline Mosquitos of the Sudan

The distribution of 29 species and three varieties of Anopheles in the Sudan is shown on maps. Notes are given on each one with particular reference to distribution. Reasons are given for regarding A. rupicolus Lewis as a synonym or local form of A. rhodesiensis Theo. The former spread of A. gambiae Giles into the Palaearctic Region in Egypt is discussed, and notes are given on its distribution in the Wadi Halfa area. The general distribution of the Sudan Anophelines is discussed. Notes are given on malaria and on Wuchereria bancrofti .

A taxonomic review of Phlebotomus (Idiophlebotomus) (Psychodidae)

Five known species (asperulus Quate & Fairchild, erebicolus Quate, pholetor Quate & Fairchild, sejunctus Quate, and stellae Quate) of the caverni‐colous subgenus Phlebotomus (Idiophlebotomus) are discussed in relation to newly recognized species from West Malaysia and India. P. frondifer n.sp. and P. tubifer n.sp. are described and a key to the adults of all seven species is given. General features of the subgenus are discussed, with particular reference to the functional relationships between the specialized morphology of the mouthparts and the probable bat hosts of these species.

The subgenus Euphlebotomus (Diptera: Psychodidae) in China, with description of a new species, Phlebotomus yunshengensis.

In 1982 many phlebotomine sandflies were collected in the mountainous area of southern Sichuan along the Sichuan and Yunnan frontier. In three places in this area specimens were found of a new species belonging to the subgenus Euphlebotomus Theodor, 1948, which includes Phlebotomus argentipes, the important vector of Kala-azar in India.