Seasonal incidence and influence of weather factors on two spotted spider mite, Tetranychus urticae Koch in Jasmine (Jasminum sambac L.) ecosystem

Abstract

A study was conducted to assess the population dynamics of two spotted spider mite in jasmine in two different climate zones ie., Madurai and Coimbatore District of Tamil Nadu. From the study, it was evident that the occurrence of two spotted mite, Tetranychus urticae was less severe during November till March and the mite population density varied from 5.28 to 8.61 mites/2 cm² leaf area in Madurai District, while the incidence was minimum from December till April in Coimbatore district with the population varying from 4.82 to 9.65 mites/2 cm² leaf area. The mite population was found to increase steadily in summer months in both the districts. From the present investigation it is evident that the two-spotted spider mite population in jasmine had a significant positive correlation with maximum temperature (r = 0.934) and (r = 0.368) and negatively for relative humidity (r = - 919) and (r = - 0.465) and rainfall (r = - 0.496) and (r = - 0.548) in Madurai and Coimbatore districts respectively. A significant positive correlation was recorded for sunshine hours and wind velocity on both the investigated districts.