IMPACT OF WEATHER PARAMETERS ON POPULATION FLUCTUATION OF HELICOVERPA ARMIGERA HUBN. INFESTING CHICKPEA IN LOWER GANGETIC BASIN OF WEST BENGAL Sabyasachi Ray and A. Banerjee* 1 Department of Agricultural Entomology, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia - 741252, India. 1 AICRP on MULLaRP, Directorate of Research, B.C.K.V., Mohanpur, Nadia - 741 252, India. *e-mail : amitavakvk@gmail.com (Received 15 May 2022, Accepted 11 July 2022) ABSTRACT : The results of the two year experiment on studying the relationship between weather parameters and the population fluctuation of Helicoverpa armigera Hubn. on different varieties of chickpea in lower Gangetic basin of West Bengal under new alluvial zone reveal that the gram pod borer reached its peak in second week of March during first year and in last week of February during second year of the experiment at the reproductive stage of the crop irrespective of the varieties under consideration. In both the years of study, the highest pest density was recorded in chickpea variety Bidhan Chhola 1 whereas it was recorded the lowest in variety KWR 108. Correlation studies indicate that gram pod borer population was positively correlated with maximum temperature, minimum temperature, wind speed and bright sunshine hour whereas the association was found negative with maximum relative humidity, minimum relative humidity and rainfall irrespective of the year of experimentation. Maximum temperature exhibited significant association with pest population on all the varieties except Bidhan Chhola 1 in first year and KWR 108 during both the years. The correlation between wind speed and pest density was found significantly positive on variety Bidhan Chhola 1 in both the years. The regression analysis shows maximum temperature as the sole governing factor in both the years of experiment to predict the pest population on three chickpea varieties like GNG 2372, KPG 59 and JAKI 9218. Key words : Chickpea, Cicer arietinum, correlation, Helicoverpa armigera, incidence, regression, variety, weather parameters. How to cite : Sabyasachi Ray and A. Banerjee (2022) Impact of weather parameters on population fluctuation of Helicoverpa armigera Hubn. infesting chickpea in lower Gangetic Basin of West Bengal. J. Exp. Zool. India 25, 2639-2648. DocID: https:// connectjournals.com/03895.2022.25.2639 J. Exp. Zool. India Vol. 25, No. 2, pp. 2639-2648, 2022 www.connectjournals.com/jez ISSN 0972-0030 DocID: https://connectjournals.com/03895.2022.25.2639 eISSN 0976-1780 INTRODUCTION Among the different pulse crops chickpea (Cicer arietinum Linn.) is the most important one based on its nutritional and ecological aspect (atmospheric nitrogen fixer, soil fertility enhancer). It is well known for presence of high quantity vegetable protein hence it is regarded as ‘King of Pulses’ (Bakr et al, 2004) and also in India it is sometimes called as “poor man’s meat and rich man’s vegetable” (Durga Bahadur et al, 2018). India is the largest producer as well as the consumer of chickpea in the country as it recorded a highest production of 112 lakh tonnes (Anonymous, 2018). Despite the gram yield is comparatively less (1063 kg/ha) that occupies 6 th position among the chickpea growing countries in the world (FAO STAT, 2019). Among the several constraints like environmental extremity (cloudiness, intermittent rainfall, frost), poor soil fertility, biotic stresses, an important one is insect pest infestation and among those pests, gram pod borer (Helicoverpa armigera Hubner) is the most noxious one having wide host range with multivoltine overlapping generation that is responsible for reduced seed yield. The pest remains on the crop from vegetative stage to pod development stage (Dhingra et al, 2003). Several lepidopteran noctuid caterpillars are found to damage the crop among which H. armigera, Agrotis ipsilon, Spodoptera litura etc. are responsible for 10-85 % crop loss (Das et al, 1997). H. armigera was observed as a serious crop pest in semi arid tropical regions distributed in the Old-World (Reed and Pawar, 1982). The pest feeds on huge number of plant species (approximately 180 species) belonging to 45 families, among them Amaranthaceae, Asteraceae, Brassicaceae, Euphorbiaceae, Fabaceae, Malvaceae, Poaceae and Solanaceae are the preferable hosts (Manjunath et al,