A dryinid wasp, Haplogonatopus atratus destroys the hosts by predation and parasitization (oviposition). Mortality by predation and parasitization was examened by exposing 30 nymphs for 24 hours to a single female. The great majority of wounded host nymphs were died within 1-3 days after predation. Eggs were not usually found in the hosts died of predation. Mortality by predation 17.6% in Laodelphax striatellus and 18.4% in Sogatella furcifera. Mortality by parasitism was 37.3% in L. striatellus and 36.2% in S. furcifera. The combined mortality by predation and parasitization reached up to about 60% in both host species.