Virulence of nematodes against larvae of the south-American fruit fly in laboratory using soil from Porto Amazonas, Paraná, Brazil, as substrate

Virulência de nematoides contra larvas de mosca-das-frutas-sulamericana em laboratório, utilizando solo de Porto Amazonas, Paraná, Brasil, como substrato

ABSTRACT:

Anastrepha fraterculus is an important orchard pest. Its management has been based in chemical sprays, but biological control is a growing demand. The objective of this work was to evaluate, under laboratory conditions, the virulence of eight nematode isolates to A. fraterculus in a soil collected in Porto Amazonas, Paraná, Brazil, and to estimate lethal doses (LD₅₀ and LD₉₀) for the more virulent isolate. Steinernema carpocapsae CB 02, three Heterorhabditis sp., two H. amazonensis and two Oscheius sp. isolates were tested in laboratory against A. fraterculus third-instar larvae using as substrate a loam Cambisol collected in an apple orchard. S. carpocapsae CB 02 isolate caused the higher percent mortality of A. fraterculus. Heterorhabditis sp. isolates and LAMIP 9 (Oscheius sp.) isolates were intermediate, while LAMIP 92 (Oscheius sp.) didn't differ from the control. S. carpocapsae CB 02 is able to kill 50% and 90% of A. fraterculus population with 96.3 and 314.7 infective juveniles per larva, respectively, in that soil. As a conclusion, CB 02 is the most virulent to A. fraterculus when the substrate is Porto Amazonas' apple orchard soil and it is able to kill 50 and 90% larval population with 96.3 and 314.7 infective juveniles per larva, respectively.

Key words:
Steinernema carpocapsae; Heterorhabditis; Oscheius; Anastrepha fraterculus