Biological control potential of native entomopathogenic nematodes against the potato tuber moth,Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) in Turkey

The biocontrol efficiency of three turkish isolates of the entomopathogenic nematodes steinernema carpocapsae,s. feltiae and heterorhabditis bacteriophora were evaluated against the last instar of potato tuber moth (ptm) phthorimaea operculella under laboratory conditions. to determine optimum nematode application rate and temperature,the experiments were conducted with 100,500 and 1000 ijs at 10,15 and 25oc. temperature and nematode concentration had a significant effect on p. operculella larval mortality. s. carpocapsae and h. bacteriophora species displayed generally increased virulence in parallel with rising temperature and the number of infective juveniles applied. at 25°c and 1000 ijs concentration,the larval mortality was 96 and 80% for s. carpocapsae and h. bacteriophora,respectively. however,s. feltiae did not exhibit more than 40% mortality at any temperature or concentration,except when the nematodes were applied in infected insect host cadavers. at 25°c,infected cadaver applications showed 97,83 and 67% mortality for s. carpocapsae,h. bacteriophora and s. feltiae,respectively. our results indicate that p. operculella larvae are quite susceptible to entomopathogenic nematode infection and,in particular,s. carpocapsae blacksea strain has a high level of potential to control this pest. copyright 2013 zoological society of pakistan.