Although Ethiopia is one of the countries worst affected by human onchocerciasis, the exact taxonomic identity of the blackflies acting as the main vectors in the endemic areas has never been determined. A cytotaxonomic analysis of Simulium damnosum s.l. collected from three endemic sites in south-western Ethiopia has now revealed the existence of the 'Kisiwani' form (a non-anthropophilic cytoform that is common in East Africa) and a newly recognized species, Simulium kaffaense. Simulium kaffaense sp. nov. is differentiated from other members of the S. damnosum complex by six fixed inversions and dozens of 'new' floating inversions. The rearing of egg batches from some of the biting adult females, to larvae or adults, indicated that the human-biting blackflies were all S. kaffaense. As S. kaffaense is not only highly anthropophilic but also, apparently, the only anthropophilic member of the S. damnosum complex present, it is likely to be the main (if not the only) vector of Onchocerca volvulus in the study area. The presence of inversion 1S-1 and a complex inversion possibly involving 1L-3 indicates that S. kaffaense either belongs or is close to the 'Nile' phylogenetic group of S. damnosum s. l. The karyotype frequencies of the inversions in the collections from the three study sites indicate that at least two forms of S. kaffaense, here designated 'Bebeka' and 'Jimma', were caught. The taxonomy and medical importance of S. kaffaense are discussed.

Three species of fruit fly parasitoids, Psyttalia concolor (Szépligeti), Psyttalia cosyrae (Wilkinson) and Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae) were reared on different host larvae to determine the effects of host species, size and colour on parasitoid development. Ovipositor, ovipositor sheath and hind tibia lengths were found to be different for progenies from preferred and non-preferred host larvae. Ratios of ovipositor -tibia and ovipositor sheath -tibia showed no difference when P. concolor was reared on a bigger host (Ceratitis cosyra (Walker) (Diptera: Tephritidae), whereas rearing P. cosyrae on a smaller host (C. capitata (Wiedemann) showed significant differences. Comparison of the linear measurements, ratios and number of flagellomeres of parasitoids reared on preferred hosts, separated the species into their natural groupings. When reared on a different-coloured host, P. lounsburyi lost its dark markings but other characters remained unchanged. Morphometric analysis also indicated differences between parasitoids reared on preferred host larvae and those reared on non-preferred host larvae. Rearing parasitoids on larvae other than their preferred hosts resulted in colour and size changes, and thus, these characters alone were not reliable for the identification of parasitoids. This is especially important in post-release sampling surveys to ascertain establishment of the parasitoids in new environments where they may adapt to new host species.Résumé. Trois espèces de parasitoïdes, Psyttalia concolor (Szépligeti), Psyttalia cosyrae (Wilkinson) et Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae) de mouche des fruits ont été élevées sur différents hô tes larvaires afin de déterminer l'incidence des espèces d'hô tes, leur taille et couleur, sur le développement des parasitoïdes. La longueur des ovipositeurs, des étuis d'ovipositeur et des tibias postérieurs des descendants est différente selon qu'ils ont été élevés sur des hô tes préférés ou non préférés. Les rapports ovipositeur -tibia et étui d'ovipositeur -tibia de P. concolor ne sont pas modifiés sur le plus * q ICIPE 2005 l'identification des espèces. Cela apparaît particulièrement important dans le cadre d'enquêtes réalisées après des lâchers afin d'évaluer l'établissement des parasitoïdes dans de nouveaux environnements lorsqu'ils doivent s'adapter à de nouveaux hôtes.Abstract.

Soil Macrofauna especially insects have been recognized as being an important factor in regulating soil processes and thereby the soil profile development. The influence of earthworms is well documented and it is the dominant member of the soil macrofauna influencing the soil formation processes in the temperate zone. In the tropics, termites and ants play the major role in the nutrient recycling and the movement and transportation of soil material. This paper describes the influence of termites on the soil formation in the tropical wet semi-deciduous forest in Ghana at the north coast of the Gulf of Guinea. The termites form distinct soil horizons especially at the summits of the landscapes where grave/free soil horizons are formed upon gravel rich horizons, and in some cases soil heaps are formed after the decomposition of huge trees.

The development of Dermestes maculatus (DeGeer) on four smoked fish substrates [Trigger fish (Balistes capriscus), Catfish (Synodontis sp.), African catfish (Clarias gariepinus) and Nile Tilapia (Oreochromis niloticus)] were investigated as completely randomized design under laboratory temperature of 30 o C, relative humidity of 65±5% and a light: darkness regimen of 12:12 hours. Females laid eggs within 24 hours of copulation. The numbers of eggs laid and the period between larval instars were not significantly different (P > 0.05). Mean total egg laying period varied from 18 days on B. capriscus to 30 days on Synodontis sp. with about 75% of eggs laid on days 13, 15, 15 and 17 for O. niloticus, B. Capriscus, C. gariepinus, and Synodontis sp., respectively. Hatching started 48 hours after copulation on all fish substrates. The mixed fish substrate (comprising all species) gave the longest (P < 0.05) developmental period of 42.75 days. Except C. gariepinus which recorded five larval instars, all others gave six instars. The total development period of D. maculatus from egg → larva → pre-pupa → pupa → adult emergence on the fish substrates decreased in the order Synodontis > O. niloticus > Mixed > C. gariepinus > B. capriscus.

The reproductive compatibility between four different species/populations of the tephritid parasitoid Psyttalia (Walker) species from Kenya and individuals of the morphologically identical Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) from a laboratory culture in Italy used in augmentative biological control of olive fly, Bactrocera oleae (Gmelin) (Diptera: Tephritidae) was assessed through cross mating tests using single-pair and group mating methods. Reciprocal crosses among the species resulted in the production of viable offsprings up to the second generation. In spite of the successful production of viable offspring in the laboratory, Psyttalia species are known to have specific host fruit and/or host fly preferences and populations/species may be isolated in one way or the other. However, it is not known whether these populations/species interbreed in the field. We discuss the ability of these parasitoids to interbreed and the potential effects of that on their use as biological control agents, especially in environments where other closely related species are present or in situations where multiple parasitoid introductions are intended.