Abstract:
The extensive and intensive survey of two-spotted spider mite (TSSM), Tetranychus urticae Koch, its biology and management on host plant, bean (Lablab purpureus L.) in Rajshahi City Corporation area were studied. The predation efficiency of three predators is discussed in considerable details. T. urticae eggs hatched to six legged larvae in the shortest duration of 1.07 ± 0.26 days in the month of April. It took the longest duration of 11.67 ± 2.33 days in the month of January. The high temperature shortened the duration of hatching period. The larval period of T. urticae took the shortest time of 0.55 ± 0.50 days m the month of May. The longest duration required to transform into protonymph from larva was 2.93 ± 1.07 days in December. The higher temperature significantly (P<0.001) reduced the larval duration.
The protonymphal duration was 0.89 ± 0.32 day in May and 3.71 ± 1.94 and 3.71 ± 1.75 days in December and January. The increase of temperature decreased the protonymphal duration remarkably.
The deutonymph required the shortest duration of 0.92 ± 0.41 days in August and the longest 10.26 ± 1.48 days in January. The temperature played significant (P<0.001) role on the duration of deutonymphal period. The high temperature accelerated the developmental rate and reduced the deutonymphal period………………………….
Description:
This Thesis is Submitted to the Institute of Biological Sciences (IBSc), University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)
