Occurrence of Stored Grain Pests in Thrissur District, Kerala, India

The aim of this study is not to eliminate all pests. Some pests are tolerable and essential so that their natural enemies remain in the crop. Rather, the aim is to reduce pest populations to less than damaging numbers. Hence the objective of the study is to enumerate the species composition and diversity of the stored grain pests of the study area. In the present study a variety of stored grain insect pests were recorded for 6 months from 2 sites in Thrissur District. For the convenience of the study the period is divided into 2 seasons. The seasonal studies were done and find the species diversity in each season through the survey and statistical analysis. From two seasons 9 species were recorded from both sites of the order Coleopteran and Lepidoptera. Sitophilus oryzae was more abundant in both monsoon and post monsoon season and second abundant species is Tribolium castaneum from Curculionidae and Tenebrionidae families respectively. Apart from Chrysomelidae, cueculionidae, Bostrichidae, Dermestidae and Carabidae were the families recorded of the order Coleoptera. Pyralidae was the only Lepidopteran family recorded during the study.

From the study on diversity of stored grain pests in two sites gives the knowledge of insect diversity in that area. Through the collection and statistical analysis different types of species were recorded from both sites. The breeding season of each species is different, so it is kindly affect their abundance. Although Sitophilus oryzae and Tribolium castaneum are more abundant in both season from both sites. Over all, the study gave an idea about the insect pest diversity of two sites from Thrissur district and abundance are more in various season during the study periods.