Two new species of Simulium (Gomphostilbia) (Diptera, Simuliidae) from Peninsular Malaysia, with keys to Peninsular Malaysian members of the Simulium ceylonicum species-group.

H Takaoka,M Sofian-Azirun,Z Ya'Cob,R Hashim

doi:10.3897/zookeys.118.1552

Abstract

Two new species of black flies, Simulium (Gomphostilbia) roslihashimi sp. n. and Simulium (Gomphostilbia) lurauense sp. n., are described on the basis of reared adult, pupal and larval specimens collected from Peninsular Malaysia. These two new species are placed in the ceylonicum species-group within the subgenus Gomphostilbia. Simulium (Gomphostilbia) roslihashimi sp. n. is most distinctive with the male having almost entirely yellow antennae, and Simulium (Gomphostilbia) lurauense sp. n. is characterized in the female by having the elongate sensory vesicle and the yellowish-white hairs on the base of the costal vein and on the stem vein, in the male by the greater number of large upper-eye facets and the spindle-shaped hind basitarsi which are much narrower than the hind tibiae and femora and in the pupa by the small terminal hooks. Keys to species of the ceylonicum species-group reported from Peninsular Malaysia are provided for females, males, pupae and mature larvae.

Highlights

The fauna of black flies (Diptera: Simuliidae) in Peninsular Malaysia is represented by 37 named and 3 unnamed species, which are all classified in the genus Simulium Latreille s. l. and are further placed in four subgenera: 1 species in Daviesellum Takaoka and Adler, 18 species (17 named and 1 unnamed) in Gomphostilbia Enderlein, 4 species in Nevermannia Enderlein, and 17 species (15 named and 2 unnamed) in Simulium Latreille s. str. (Crosskey 1973; Edwards 1928; Takaoka 2000, 2008; Takaoka and Adler 1997; Takaoka and Davies 1995, 1997; Takaoka et al 2010, 2011)
In recent surveys on pupae and larvae of black flies in Peninsular Malaysia, we collected two new species, both of which are assignable to the subgenus Gomphostilbia, redefined by Takaoka (2003), by having a bare pleural membrane and a haired katepisternum in the female and male adults, grapnel-shaped hooklets on each side of the ninth pupal abdominal segment and a hypostoma with smooth lateral margins in the larva, and further, within the subgenus, are placed in the ceylonicum species-group by having an enlarged male hind basitarsus, a diagnostic morphological characteristics separating this species-group from other species-groups (Takaoka 2003)
These two new species are very similar in the arrangement of the eight pupal gill filaments, one of the key morphological features most frequently used to identify the species in the pupal stage, but are readily distinguishable in the adult stage from each other

Summary

Introduction

The fauna of black flies (Diptera: Simuliidae) in Peninsular Malaysia is represented by 37 named and 3 unnamed species, which are all classified in the genus Simulium Latreille s. l. and are further placed in four subgenera: 1 species in Daviesellum Takaoka and Adler, 18 species (17 named and 1 unnamed) in Gomphostilbia Enderlein, 4 species in Nevermannia Enderlein, and 17 species (15 named and 2 unnamed) in Simulium Latreille s. str. (Crosskey 1973; Edwards 1928; Takaoka 2000, 2008; Takaoka and Adler 1997; Takaoka and Davies 1995, 1997; Takaoka et al 2010, 2011).In recent surveys on pupae and larvae of black flies in Peninsular Malaysia, we collected two new species, both of which are assignable to the subgenus Gomphostilbia, redefined by Takaoka (2003), by having a bare pleural membrane and a haired katepisternum in the female and male adults, grapnel-shaped hooklets on each side of the ninth pupal abdominal segment and a hypostoma with smooth lateral margins in the larva, and further, within the subgenus, are placed in the ceylonicum species-group by having an enlarged male hind basitarsus, a diagnostic morphological characteristics separating this species-group from other species-groups (Takaoka 2003).These two new species are very similar in the arrangement of the eight pupal gill filaments, one of the key morphological features most frequently used to identify the species in the pupal stage, but are readily distinguishable in the adult stage from each other.

Results

Conclusion