Species and Population Density of Predatory Mites on Durian

Abstract

The study was carried out during January to December, 1991 to ascertain the species and population density of predatory mites associated with durian in chemical and nonchemical-sprayed orchards. Mite specimens were collected at monthly interval from the two durian orchards of Banpongrad district in Chanthaburi province. Results from the investigation resvealed the occurrences of 4 families of predatory mites on durian. They were Phytoseiidae, Stigmaeidae, Cunzxidae and Bdellidae.
Phytoseiidae which is generally knows as the most effective predators was the most abundant family found in durian orchards. Their population collected througout the year in the nonchemical-sprayed orchard was 352 while in the chemical-sprayed orchard was 47. The population of these phytoseiid mites was found to be very abundant during May to October which is the rainy season. At least 6 species of phytoseiid mites were found associated with durian. They were Amblyseius sp. (bet. deleoni and phillipsi0, Amblyseius sp. (nr. heidrunae) A. cinctus Corpuz et Rimando, A. syzygii Gupta, A. paraaerialis Muma and A. longispionosus (Evans). Among which Amblyseius sp. (bet. deleoni and phillipsi) is th emost abundant species. Predatory mite of the family Stigmaeidae, Agistemus sp., was found to be more abundant in the chemical-sprayed orchard. Their population was observed to be more abundant during the drought period (December to April). The population of other predatory mites in the families Cunaxidae and Bdellidae was found to be very low throughout the period of this study.