Synanthropy of Carrion Flies in Three Districts of Southern West Bengal, India

摘要

Knowledge of synanthropic relationships among different sarcosaprophagous fly species is of prime interest not only from the standpoint of animal ecology but also from the standpoint of hygiene. The present work attempts to identify synanthropic species, to develop synanthropic index for each species, and to correlate abundance of flies in relation to human habit, habitation, and sanitation. Flies of Calliphoridae, Parasarcophagidae, and Muscidae were trapped from 12 localities in Midnapore, Hooghly, and North-24-Parganas districts in the state of West Bengal (India). Altogether 23 species of flies from 14 genera were identified from these localities. Maximum number of species in a genus was five (Sarcophaga and Musca) followed by two under Lucilia and Chrysomya. None of 12 species of Muscidae was common in,all the studied localities. Six out of 23 species were found in one study locality. Synanthropic index (SI) of females of most of the species was higher than those of the males in most of the seasons. Results showed that SI was the highest for M. domestica in all the four groups followed by Chrysomya megacephala and Musca sorbens. Variation in SI of species in different districts reflected the habit and culture in the local human settlements. All of the sarcophagid flies trapped during the present investigation were negatively synanthropic. Members of Sarcophaga were less important in terms of disease transmission. Our results categorically point to the preferred habitats of these carrion flies, and would help in assessing the sanitation and habitat status of human settlements.