Fenazaquin resistance development and management in two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

Abstract Fenazaquin resistant population of two-spotted spider mite, Tetranychus urticae (Koch) was developed by giving selection pressure. After 8 generations, the resultant population of mite obtained having resistance ratio of 216.74 folds (FR-strain) as compared to susceptible population (S-strain) maintained in the laboratory. FR-strain was found to have resistance breakdown upto 158.82-times when selection pressure was withdrawn for three generations. Developmental stages of fenazaquin resistant strain were bigger in size and took lesser number of days to complete incubation period, development of immature stage and total life cycle than in susceptible strain. However, fecundity and adult longevity of S-strain was more than FR-strain. The FR-strain was examined for cross resistance against different acaricidal products, namely, hexythiazox (5.45 EC), propargite (57 EC), azadirachtin (0.15 EC), Darekastra and Tamarlassi. These resulted in lower value of resistance ratio, being < 2 suggesting their incorporation in managing fenazaquin resistant population of T. urticae.