Impact of different pest management practices on natural enemy population in tea plantations of Assam special emphasis on spider fauna

Abstract

Tea is a perennial monoculture crop infested by approximately thousand species of pests. Conserving natural enemies is an important practice under non-conventional pest management strategy. In the present study, occurrence of spider population on tea in three different pest management practices has been studied in three different agro climatic region of Assam. The three pest management practices include: 1. Ecological Crop Management (ECM: wherein pest management is achieved with cultural practices, mechanical practices and biopesticide excluding synthetic pesticides); 2. Integrated pest management (IPM: includes recommended IPM practices with use of only CIB recommended approved dose of synthetic pesticides); 3. Garden practice (GP: involves normal practices being followed in tea garden). During the study, very high incidence of natural enemy population was recorded under ECM followed by IPM and the least with GP. Spiders are the most common predators and constituted about 50–90% of the total natural enemy count. Number of spiders captured during monsoon was significantly higher than pre-monsoon and post monsoon. Family Salticidae was found to be the dominant group among the recorded spider taxa. The study inferred that though ecologically managed plantations encourage the spider diversity along with different natural enemies, integrated management practices can also be adopted by conventional garden for better natural enemy population if going to ECM is not at all been an option.