Diopsis spp.

Feijen, Hans R., Feijen, Cobi & O., P., 2019, An annotated catalogue of the stalk-eyed flies (Diopsidae: Diptera) of India with description of new species in Megalabops Frey and Teleopsis Rondani, Israel Journal of Entomology (Oxford, England) 49 (2), pp. 35-72 : 47

Diopsis spp.

Remarks: With D. abdominalis and D. indica , two species are now recognised for India in the D. indica species-group. There is no doubt, that more species will be described from India, especially her northern parts. Vazirani and Rathore (1976) noted “variations” within the NZSI collection of “ D. indica .” Datta and Biswas (1985) listed next to D. indica also a Diopsis nr indica .

All Oriental Diopsis belong to the large D. indica species-group, one of the four Diopsis species-groups with a large apical wing spot ( Feijen & Feijen 2009). The other three species-groups are the Afrotropical D. apicalis Dalman group, D. atricapilla Guérin-Méneville group and D. cruciata Curran group with a large apical wing spot (Feijen & Feijen 2012).Although there are superficial similarities between the species of the D. indica species-group and the three Afrotropical groups, these four species-groups do not form a monophyletic clade. Provisional DNA analyses clearly indicate the three Afrotropical species-groups do form a monophyletic clade, whereas the D. indica species-group might be somehow related to the Afrotropical Diopsis circularis species-group with a large central wing spot and at most some apical infuscation. This appears, at first sight, strange from a morphological point of view, but some similarities can be indicated. In both groups specific pollinosity patterns can occur on the abdomen, which is unusual in Diopsis . Furthermore, both groups are sexually homomorphic with regard to the eye span. This also forms a major difference compared to the Afrotropical species-groups with a large apical wing spot, which are all sexually dimorphic in this regard. Homomorphy appears to be the rule in the D. indica group. In a large sample (n=50) of an undescribed Sri Lankan species the rate of dimorphism was slightly negative: D=-0.1. In D. westwoodii D appears even more strongly negative, but that concerned only a very small sample (n=11).