Studies on population dynamics, seasonal incidence and control of legume bud thrips megalurothrips sjostedti (trybom) (thysanoptera: thripidae) in cowpea fields in the Coast Province of Kenya

Abstract

Studies on population dynamics seaoonnl incidence and control of the legume bud thripa Meqalurnthrips s.jostedti Trybom were carried out at the Coast Agricultural Research Station, Mtuapao Coupea resistance to thrips attack was also tested using local and exotic varieties© All experiments were randomised block design in plot size 3m x 3m© Thrips population levels were estimated from random samples of 10 flowers per plot in the replicates© Population levels varied with seasons with significantly more thrip3 occurring during the long rains season. Rapid thrips papulation huild-up appeared tc correspond with the peak flowering period of the cowpea crop. In general, population levels were influenced h l» nimiil nti wo ri'iffhoT> nf FI ni.tnrn nr* r> r* h nnnrnn He < 1 w - > --------- — ------- — • • — — w w w' * * “ I weather changes e.n© rainfall, relative humidity and temperature did not appear to influence thrips population directly. Varieties VITA 3 and Katumani 1 were the most susceptible© Female thrips occurred in larger numbers compared to males suggesting presence of parthenogenetic reproduction© All the three insecticides tested, namely, Sevin B5UP, Thiodan 35£C and DDT 25% significantly depressed thrips population with four weekly applications of Thiodan being the most effective©