Dipti Lata*, Silva Kanta Lakra & Seema Keshari
University Department of Zoology, Ranchi University, Ranchi, Jharkhand, India
Received : 24th December, 2020 ; Revised : 16th January, 2021
Abstract : Present work deals with the variation in population of aquatic coleoptera species in a freshwater body, i.e. the Joda Talab of Bariatu area in Ranchi, Jharkhand on account of changes in physico-chemical parameters such as pH, temperature and dissolved oxygen. The study was conducted from October-2019 to February 2020 i.e. the post monsoon to winter season. During the study period total 3 families of order coleopteran i.e. Gyrinidae, Dytiscidae and Hydrophilidae were recorded from the two sites of the Talab. Among these families, Gyrinus species of Gyrinidae was found in high number at both the sites as they prefer cooler environment for breeding and development. Except these, species of other families declined from October to December and then increased till February. Site 1 with greater number of individual was recorded with low pH values. Similarly decline in temperature from October to January was seen with rise in DO values which was accompanied with increase in number of insect species. Whereas site 2 with high pH, low dissolved oxygen and seasonal changes of temperature, was accompanied with less number of individuals. Thus the study revealed that pH, temperature and DO play an important role in difference of population density of aquatic insects.