<b>Flies matter: a study of the diversity of Diptera families (Insecta: Diptera) of Mumbai Metropolitan Region, Maharashtra, India, and notes on their ecological roles</b>

Abstract

Diptera is one of the three largest insect orders, encompassing insects commonly known as ‘true flies’. They are one of the most important in terms of their interactions with humans. Family-level diversity of Diptera was studied in the Mumbai Metropolitan Region (MMR)—50 families were recorded in four protected areas—Sanjay Gandhi National Park, Tungareshwar Wildlife Sanctuary, Karnala Bird Sanctuary, and Matheran Eco-Sensitive Zone, of which 24 were also found in urban areas of Mumbai and Thane City. The MMR’s family-level dipteran diversity constitutes 78% of families documented in the Western Ghats and 57% of India’s known families of Diptera. The recorded Diptera families were segregated into two groups based on their habits - beneficial and pestiferous. Of the 50 families, 66% comprised members which were beneficial in terms of flower visitations (28%), decomposition (24%), and predators and parasitoids of pest insects (14%), whereas 34% comprised members that were pestiferous in nature in terms of posing a threat to human health and causing nuisance (11%), causing crop and food damage (12%), posing a threat to animal health (8%), and as parasitoids of beneficial insects (3%). In terms of their feeding preferences, the majority of the adults were flower visitors (26%), 24% were saprophagous, followed by members that were frugivorous, fungivorous, coprophagous, and predatory in nature. Among larval feeding habits, 31% were detritivorous, 18% phytophagous, and 13% predatory in nature. In terms of their habitat preferences, 24 families were found in dense undergrowth, 12 in mountainous forests, and 11 in fruit gardens. This study establishes that Diptera is more diverse in natural areas than urban areas, and emphasizes the need for further exploration in terms of taxonomic and ecological studies, and economic benefits vis-à-vis the losses they incur in the region.