earticle

영어

Pathogenicity of Steinernema carpocapsae GSN1 strain was evaluated against Morophagoides moriutii larvae. In Petridish tests, insect mortality by the nematode was dose dependent, which increased with dose from 5 to 160 infective juveniles(IJs)/larva. Pathogenicity against fourth-instar larvae was higher than the rate of corresponding second- and third-instar larvae, showing 100% insect mortality with the dose of 40 IJs/4th instar larva and 80 IJs/2nd or 3rd instar larvae. Lethal concentration values at 50% (LC50) of S. carpocapsae GSN1 strain were 4.2 IJs/2nd instar larva; 8.5 IJs/3rd instar larva; and 2.3 IJs/4th instar larva, respectively. The number of nematodes established in M. moriutii larvae after infection increased in the increment of dose and insect developmental stage. The highest number of nematodes was harvested from fourth instar larvae of M. moriutii at a dose of 160 IJs per larva, showing 22.5 nematodes per insect larva. Nematode reproductive capacity was related to insect developmental stage, showing 6,335 IJs/2nd instar larva, 21,660 IJs/3rd instar larvae, and 88,700 IJs/4th instar larvae.