An interpretation of the morphological variation in the Simulium amazonicum species group (Diptera: Simuliidae) of Latin America

Abstract

A morphological framework for species within the medically important Simulium amazonicum group within the subgenus Psaroniocompsa Enderlein is provided as a basis for cytological and molecular studies. The diagnostic characters for pupae and adults of the group are provided and the male genitalia are regarded as the major defining feature for the group. Short descriptions of the pupae and adults of each species are given together with digital images of salient characters, largely from type specimens. Variation in pupal characters and adult scutal pattern are comprehensively covered. The taxonomic changes in the amazonicum group from that given in the latest world inventory of Crosskey and Howard (2004) are as follows: S. argentiscutum Shelley & Luna Dias, S. cuneatum (Enderlein), and S. quadristrigatum Enderlein are transferred from “unplaced to group” to the amazonicum group; S. minusculum Lutz is removed from the amazonicum group to “unplaced to group”; two new forms (R. Mari and R. Ituxi) are described within S. amazonicum s.l.; the Argentina, and Manabi forms [previously within S. oyapockense s.l.] are placed together with S. roraimense s.s. as S. roraimense s.l. The amazonicum group now contains 10 species. Within the closely related siolii group, S. lourencoi Py-Daniel becomes a junior synonym of S. siolii Py-Daniel. The elevation of the siolii group to the new genus Shelleyellum Py-Daniel & Pessoa is not accepted because of insufficient characters to warrant generic status. Shelleyellum, with its type species S. siolii, is synonymised with Simulium s.l. Latreille.