DIURNAL AND DOSE RESPONSES OF MALE CHINESE LARCH CASEBEARER, COLEOPHORA-SINENSIS YANG (LEP, COLEOPHORIDAE) TO SYNTHETIC SEX-ATTRACTANT

Field experiments on the Chinese larch casebearer, Coleophora sinensis Yang, with special reference to diel and dose responses of males to i ts sex-attractant (Z5-10:OH) in the Larix principis-rupprechtii Mayr. plantations in Shanxi province of China were carried out from 1992 to 1993. Trap captures increased with a raise in the Z5-10:OH dose up to 100 mu g, at all the sites tested. They did not significantly differ f or the 100 mu g, 500 mu g and 1000 mu g doses in sticky traps (1992) a nd decreased obviously when the dose increased from 100 mu g up to 100 0 mu g in non-sticky Unitraps (1993). Thus, 100 mu g Z5-10:OH was acco rdingly defined as an optimal (standard) lure for C. sinensis. Seasona l flight activity, including flight initiation, duration, termination as well as the peak, as monitored by pheromone traps varied with altit udes of the sites where the field experiments took place. Trapping tes t using 100 mu g and 1000 mu g Z5-10:OH revealed a daytime attraction response pattern occurring from 06:00 h to 20:00-21:00 h with response peaks recorded at 10:00-12:00 h (minor) and 17:00-20:00 h (major). Ad ditionally, the significant effects of Z5-10:Ac, and Z5-12:OH, as attr action-inhibitors were a ain clearly confirmed in the field using non- sticky Unitraps.