BIOCONTROL POTENTIAL OF SOME ENTOMOPATHOGENIC NEMATODES AGAINSTSTELIDOTA GEMINATA (SAY)

Abstract

Stelidotageminata(Say)(Coleoptera: Nitidulidae), also known as strawberry sap beetle is considered to be serious pest of strawberry worldwide. Allstages of this pest feed on ripe fruitswhichmakes its control with chemical insecticides extremely difficult. This work was testingsusceptibility of last instar larvae of S. geminatato three, among commerciallythe most commonly used species of entomopathogenic nematodes Heterorhabditisbacteriophora, Stei-nernemacarpocapsaeand Steinernemafeltiae(Rhabditida: Heterorhabditidae and Steinernematidae), including two native strains. The present work was carried out through two typesof the experiments.First experiment was in plastic Petri dishes with the nematodes applied on filter paper. Second one, in attemptto approachto more natural conditions, effect of the entomopathogenic nematodes on insect’smortality was tested in containers filled with sand.Mortality of S. geminatalarvae in Petri dishes in highest nematode concentrations of about 100 infective juveniles per cm2was 90%,82% and 70% for commercial strains of S. carpocapsae, H. bacteriophoraand S. feltiaeand 76% and 64% for H. bacteriophoraand S. feltiae native populations. In containers with sand mortality was higherthan in Petri dishesand the highestrecorded insect mortality with about 50nematodes per cm2was99.5%, 89%, 75.5%, 69% and 66% with commercial strainsS. feltiae,S. carpocapsaeand H. bacteriophora, and native strains H. bacteriophora andS. feltiae,respectively