Bio-ecology and seasonal incidence of thrips Scirtothrips dorsalis Hood in rose

Abstract

In rose. Scirtothrips dorsalis is the dominant insect species causing damage to tender shoots, leaves, buds, flowers and growing tips of rose plants in field and polyhouse. Rose thrips prevailed throughout the flowering period and attained peak during May. Thrips followed an annual pattern in distribution over time. Thrips numbers were more in polyhouse than in open field. Cumulative mean numbers of thrips was more in polyhouse than open fields. Temperature and sunshine hours were found to have positive effect on thrips density. Relative humidity, rainfall and wind velocity had negative effect. Temperature and relative humidity largely influenced seasonal incidence of thrips. In general, the biology was short in field compared to laboratory. Newly emerged adults were yellow with rectangular head. Eyes were very prominent and pink. Total fecundity ranged from 6 to 11 per female. Adult female longevity ranged from 4 to 8 days.