Seasonal Abundance of Red Cotton Bug, Dusky Cotton Bug and Mealy Bug in Bt Cotton, Gossypium hirsutum L. and Their Correlation with Abiotic Factors

Abstract

In cotton, a number of insect pests simultaneously occur and cause enormous damage to crop. Hence, an investigation on seasonal abundance of different sucking pests in Btcotton cultivar was carried out during 2022 and 2023 at S. D. Agricultural University, Sardarkrushinagar, Gujarat, India. The order of sequential occurrence of different bugs in Bt cotton was mealybug > red cotton bug > dusky cotton bug.The population of red cotton bug built up gradually and showed its peak level during the 48th SMW (8.14 red cotton bugs/plant). The relatively higher activity was observed during the 45th SMW to 50th SMW i.e. peak boll bursting stage. Incidence of dusky cotton bug gradually increased and showed its highest peak (3.38 dusky cotton bugs/boll) during the 46th SMW and incidence was observed during later stage (after the boll bursting stage). The population of mealybug was commenced from 34th SMW increased steadily from 36th SMW and showed the highest peak during the43rd SMW with a population of 3.72 mealy bugs per 10 cm twig. The relatively higher activity was observed during 40th SMW to 47th SMW. Red cotton bug, dusky cotton bug and mealybug showed negative and significant relationship with minimum temperature, morning relative humidity and wind speed whereas, it has shown positive and highly significant correlation with sunshine hours.