A new species of Ischiodon Sack (Diptera, Syrphidae) from Madagascar

Ximo Mengual

doi:10.3897/afrinvertebr.59.24461

Abstract

The flower fly genus Ischiodon Sack (Diptera, Syrphidae) is revised and a new species, Ischiodonastales sp. n., is described from Madagascar. Additionally, a lectotype for Ischiodonaegyptius is designated and the first records of Ischiodonscutellaris for the Arabian Peninsula are reported. Diagnoses, illustrations, synonymies and distributional data are given for all described species, as well as an identification key to all known species.

Highlights

The genus Ischiodon Sack, 1913 (Diptera, Syrphidae) is a small, but very characteristic genus, with a very broad distribution and a taxonomic history full of confusion and synonyms (Vockeroth 1969)
A new species of Ischiodon is described from the southern regions of Madagascar
It should be noted that the male holotype and the four female paratypes of I. astales sp. n. were found amongst more than 200 specimens of Ischiodon aegyptius collected over several years (2002–2008) using Malaise traps

Summary

Introduction

The genus Ischiodon Sack, 1913 (Diptera, Syrphidae) is a small, but very characteristic genus, with a very broad distribution and a taxonomic history full of confusion and synonyms (Vockeroth 1969). The confusion of Ischiodon as a valid genus is due to its superficial morphological resemblance with the genus Simosyrphus Bigot, 1882. This confusion started when Bezzi (1912:72) synonymised Syrphus grandicornis Macquart, 1842 ( Simosyrphus grandicornis) under Ischiodon scutellaris (Fabricius, 1805). Species of both genera have been previously placed under one another several times (Mengual 2015, see below under each species), despite some important differences in the male genitalia (Vockeroth 1969). Mengual et al (2018) resolved both genera as related to Scaeva but the genus Pseudodoros as sister group of Ischiodon; current evidence supports the generic rank of Ischiodon and Simosyrphus

Objectives

Methods

Results

Conclusion