Phlebotomine sandflies of Kenya (Diptera: Psychodidae). I. The validity of Phlebotomus (Larroussius) elgonensis Ngoka, Madel and Mutinga

Numerical taxonomy of Old World Phlebotominae (Diptera: Psychodidae). 1. Considerations of morphological characters in the genus Phlebotomus Rondani & Berté 1840

Numerical analyses (correspondence analysis, ascending hierarchical classification, cladistic approach) were applied to the morphological characters of the adults of the genus Phlebotomus Rondani & Berté 1840. They confirm the reliability of the classic classifications, and also redefine the taxonomic and phylogenetic position of certain taxa. Thus, Spelaeophlebotomus Theodor 1948. Idiophlebotomus Quate & Fairchild 1961 and Australophlebotomus Theodor 1948 deserve generic rank. Among the vectors of leishmaniasis, the subgenus Phlebotomus Rondani & Berté 1840 is probably ancient. The results attribute an intermediate taxonomic and phylogenetic position to the taxa Euphlebotomus Theodor 1948 and Anaphlebotomus Theodor 1948, and reveal the probable artificial nature of the latter. The comparatively large numbers of species of subgenera Paraphlebotomus Theodor 1948, Synphlebotomus Theodor 1948 and, above all, Larroussius Nitzulescu 1931 and Adlerius Nitzulescu 1931, suggest that they are relatively recent. The development of adult morphological characters, the validity of their use in taxonomy and proposals for further studies are discussed.

A new sandfly species, Phlebotomus (Larroussius) ashfordi (Diptera, Psychodidae) from Ethiopia, previously confused with P. (L.). aculeatus

The sandfly subgenus Phlebotomus (Larroussius) contains species which transmit parasites causing cutaneous and visceral leishmaniasis in East Africa, including Ethiopia. The Gewasha caves in central Ethiopia harbour a new species (Phlebotomus ashfordi) belonging to the subgenus Larroussius and previously identified as P. (L.) aculeatus Lewis, Minter and Ashford. Although generally similar to P. (L.) aculeatus and P. (L.) elgonensis Ngoka, Madel and Mutinga, the species is distinct in eight male characters and in the female spermatheca. Given its taxonomic affinity to known vectors of cutaneous leishmaniasis and the presence of disease in the Gewasha caves area, the medical importance of this species needs to be assessed.

A study of phlebotomine sandflies (Diptera:Psychodidae) in Yunnan Province. V. Phlebotomus (Larroussius) lengi sp. nov

A new species of the subgenus Larroussius Nitzulescu 1931, named Phlebotomus lengi in honour of the Chinese sandfly taxonomist Professor Yan Jia Leng, was found amongst the phlebotomine sandflies collected in Yunnan Province, China, in 1989. A full description of the male and female of this species is provided. The ascoid formula of P. lengi distinguishes it from all previously described members of the subgenus Larroussius.

Phlebotomine sandflies of Kenya (Diptera: Psychodidae). IV. The armature in the genital atrium of female Larroussius as a means of identification

Descriptions are given of armatures in the genital atria of the six known Kenyan species of phlebotomine sandflies of the subgenus, Larroussius, namely Phlebotomus aculeatus, P. elgonensis, P. guggisbergi, P. longipes, P. orientalis and P. pedifer. Phlebotomus aculeatus, P. longipes and P. pedifer can be recognized by the shapes of their armatures. Differences in the length and arrangement of the spines in the armature of P. elgonensis and P. longipes are diagnostic features. The distinguishing feature of P. guggisbergi is a wide variation in spine thickness. The most notable feature of P. orientalis is the angle at which the spines lie. The appearance of the base of the spermathecal duct remains the method of choice for the identification of all six but, if this feature is not well displayed in dissected females, they can be distinguished by the armature. It is suggested that descriptions of new species should include an illustration of the armature in the genital atrium.

Phlebotomine sandflies of Kenya (Diptera: Psychodidae). III. The identification and distribution of species of the subgenus Larroussius

The six species of phlebotomine sandflies of the subgenus Larroussius recorded in Kenya are Phlebotomus aculeatus, P. elgonensis, P. guggisbergi, P. longipes, P. orientalis and P. pedifer. Five are proven vectors of leishmaniasis in that country or elsewhere. Males of all six can be identified by the morphology of the aedeagus or the number and position of the hairs on the inner surface of the coxite. Additional features separating some of the species are the sizes of the palpal and antennal segments. The females have usually been considered difficult or impossible to distinguish. A comparison of the base of the spermathecal ducts is made and it is shown that all six can be identified by this character alone. A map of Kenya is given, showing the presently known distribution of the six Larroussius species. Further surveys are necessary in parts of the country that have not been systematically surveyed.

Studies on the Phlebotomus fauna of Mount Elgon, Kenya

In a study of sandflies in 229 of 237 caves found on the slopes of Mount Elgon, Kenya, the Phlebotomus (Larroussius) species P. pedifer and P. elgonensis were found distributed at different altitudes. The females of these two species, which were the only ones of the genus Phlebotomus encountered in the study, were morphologically indistinguishable using existing techniques at the time. On the basis of the morphological identification of the males, however, P. pedifer occurred mainly at the lower altitudes (1750-1900 m) while P. elgonensis predominated at higher altitudes (2300-2600 m). The man-biting activities and the presence of promastigotes in the guts of female sandflies were restricted to lower altitudes (below 1900 m), i.e. the area of maximum distribution of P. pedifer and of cases of cutaneous leishmaniasis. This supports the suggestion that P. pedifer is a vector of cutaneous leishmaniasis on Mount Elgon.