Population Dynamics of Tomato Russet Mite , Aculops lycopersici ( Massee ) and Its Natural Enemy , Homeopronematus anconai ( Baker )

Developmental rates of Aculops lycopersici increased linearly as rearing temperature increased. A total of 81.2 degree-days above a developmental zero of 10.5°C were required to complete development from egg to adult emergence. Adult longevity decreased with increasing temperature. The highest intrinsic rate of natural increase was observed at 25°C as 0.253 per day. The population increased exponentially on greenhouse tomato plants and the intrinsic rate of natural increase was estimated to be 0.175 per day. A. lycopersici first reproduced on the released leaves then moved upward. The infestation caused great injury to the plants, with a large number of leaves turning brown and then drying up. The number of leaves, the plant height and the diameter of the main stem of the plants all decreased. Homeopronematus anconai naturally occurred on tomato plants. After the rapid population increase of H. anconai, the A. lycopersici population decreased sharply. An adult H. anconai consumed an average of 69.3 A. lycopersici deutonymphs per day in the laboratory. H. anconai was thought to be a prospective natural enemy of A. lycopersici. Discipline: Insect pest Additional key words: population growth, injury, developmental zero, thermal constant, biological control