Abstract: Casuarina tree, a main tree species in Fujian Province in sandwind break, is infested by Zeuzera multistrigata Moore. The results showed that Steinernema feltiae, an entomopathogenic nematode, was an effective parasite to suppress the population of Zeuzera pest. The comparison of infectivity of 9 steinernematid strains indicated that Steinernema feltiae Beijing is the best one. The Zeuzera larvae, young and mature, and pupae were all infected by Beijing strain of Steinernema feltiae. The temperature had effect on the mortality and killing speed of Zeuzera larvae infected by nematodes. The temperature range for nematodes infection is from 15-30℃. The quickest killing speed was gained at 25℃ with the mortality of 100% within 48 hours. The nematode was able to spread to the distance of 8cm to parasitize Zeuzera larvae in an infested tunnel. Application dosage of the nematode influenced the mortality of Zeuzera larvae. 61.5% and 100% larvae died under the dosage of 50 500 nematode juveniles per ml respectively. No difference in mortality happened when the dosage of nematode was above 500 juveniles per ml.Four methods of nematode application were tested. The best method is to stuff a small spiece of foam mixed with nematodes about 1000 juveniles. This application method was used in 25.3 hectares for control of Zeuzera larvae in Fujian Province.

Key words: Steinernema spp., Zeuzera multistrigata, Infectivity