Int.J.Curr.Microbiol.App.Sci (2020) 9(9): 114-117 114 Original Research Article https://doi.org/10.20546/ijcmas.2020.909.014 Effect of Weather Parameters on Population Buildup of Predatory Coccinellids and Spiders Present in Brinjal Crop Ecosystem of Assam Rudra N. Borkakati* and D. K. Saikia AICRP on Biological Control, AAU, Jorhat Centre Department of Entomology, Assam Agricultural University, Jorhat-785013, India *Corresponding author ABSTRACT Introduction Brinjal, Solanum melongena L. is a nutritious and delicious solanaceous vegetable grown all over India. It is often known as "poor man's vegetable" as well as “King of vegetables” due to popularity amongst common people. In regards to production, India produces 12.8 million metric tonnes per annum from an area of 7.30 lakhs hectare (Anon, 2018). Interestingly, different types insect pests along with their natural enemies are present in brinjal crop ecosystem (Borah et al.,2016 and Borkakati et al., 2019a) and conservation of natural enemies can reduces the dependence on harmful pesticides (Borkakati et al., 2019b). Therefore, proper understanding of biocontrol agents is very much essential in brinjal ecosystem. However, weather parameters play an important role for population buildup of natural enemies along with their pests. Saikia et al., 2020 reported that the significant positive correlation of aphid, Aphis gossypii Glover (r= 0.662) and International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 9 (2020) Journal homepage: http://www.ijcmas.com Field investigation was carried out during rabi seasons of 2017-18 at the farmer’s field, Allengmora, Jorhat to study the effect of weather parameters on population buildup of some predators on brinjal ecosystem. Correlation studies revealed a significant positive association of coccinellid predators with maximum temperature (r= 0.669). Moreover, all the parameters were showed a positive association with coccinellids except average relative humidity (r= -0.259) which showed a negative impact. However, population buildup of spiders influenced by maximum temperature (r= 0.242), minimum temperature (r= 0.106) and bright sunshine hours (0.373) positively, but, average relative humidity (r= -0.449) and total rainfall (r= - 0.149) showed a non-significant negative impact during the present study of investigation. Keywords Weather parameter, Population build up, Coccinellids, Spiders, Brinjal ecosystem Accepted: 04 August 2020 Available Online: 10 September 2020 Article Info