Study of Arthropod Pest of Tea and It'sdiversity in Teesta Valley Tea Garden, Darjeeling

Abstract

Arthropod Pest of Tea of Teesta Valley Tea Garden (TVTG) wasobserved during the period of two seasons (Autumn, OCT-NOV 2006 andMonsoon, JUNE-JULY 2007). Altogether 359 arthropod pests werecollected including 16 families7orders and 13 species. The species diversity of autumn season was found to be 1.62 and ofmonsoon is 1.73 while evenness of autumn is 0.904 and of monsoon is0.889. The community dominance of both seasonswas found to be 0.997. For the collection, sweeping insect net, forceps, camel hair brush wasused and after collecting, killed byputting in 70% alcohol in vials. Thenthey were brought to the lab and identified. Altogether 359 specimens were collected, 140 specimenswere foundduring the monsoon and 219 during autumn season. Maximum populationsof pests were collected from Family Formicidae and Aphididae andminimum population were collected from Chrysomellidae and Scarabaeidae.Similarly 0rder Lepidoptera was found to be dominant while Ordercoleopteran wasfound to beleast dominant. The relation exhibited between the insect population and differentenvironmental factors like temperature and rainfall showed that with theincrease of maximum temperature the population of pest also risessignificantly and with increase of rainfall the population of pest falls down.India's famous Darjeeling tea may be laced with pesticide residues,threatening tea exports. And has received negative feedback from theconsumers on pesticide residue. As a result of continuous use of pesticide,the plants resistance to pests and disease has declined. At the same time,increased pesticide use has made pest immune to the chemical. It issuggested to monitor the pests throughout the year and use of IPMtechniques as far as possible.