Acta Entomologica Sinica ›› 2019, Vol. 62 ›› Issue (7): 868-876.doi: 10.16380/j.kcxb.2019.07.010

• RESEARCH PAPERS • Previous Articles     Next Articles

Species composition, abundance and seasonal occurrence of the sap beetles (Coleoptera: Nitidulidae) in a peri-urban area of Kolkata, India (In English)

Jhikmik DASGUPTA1,*, Tarun Kumar PAL2   

  1. (Zoological Survey of India, ‘M’ Block, New Alipore, Kolkata700053, India)
  • Online:2019-07-20 Published:2019-07-09

Abstract: 【Aim】A large majority of the sap beetle fauna of India thrives on rotten fruits and vegetables and their populations show considerable seasonal fluctuations over the year. It has been hypothesized that the population of sap beetles are largely dependent on environmental variables like temperature, humidity and rainfall. 【Methods】 The species composition, seasonal incidence and population structure of sap beetles (Coleoptera: Nitidulidae) were investigated in Garia, a peri-urban area of Kolkata, India from 2013 to 2015. Period of their activity, seasonal abundance and factors influencing their occurrence were recorded. 【Results】Altogether six species were encountered in varying numbers in the peri-urban area of Kolkata, India during the study period. The most commonly collected sap beetle was Urophorus humeralis. This species was encountered for the largest number and during almost all months of the year. Other common species were Epuraea ocularis and E. luteola. Different species entered into the trap in successive stages of the fermenting food. Epuraea spp. were intercepted in the first 12 h while U. humeralis was mostly found in later successive stage when the food in the bait trap was severely rotten. The species richness was the highest in an optimum range of atmospheric temperature (22℃ to 29℃) and relative humidity (82.5% to 86%), demonstrating that these environmental variables have considerable influence over sap beetle population.【Conclusion】Major fruits and vegetables grow during the post-monsoon season in Kolkata. Sap beetles which feed on these crops show the highest incidence both in terms of species richness and abundance during the post-monsoon season. The study result may help in designing effective field management strategy for these beetles.

Key words: Nitidulidae, sap beetles, species diversity, seasonal variation, environmental factors, Kolkata, India