EKSPLORASI NEMATODA ENTOMOPATOGEN PADA LAHAN TANAMAN JAGUNG, KEDELAI DAN KUBIS DI MALANG SERTA VIRULENSINYA TERHADAP Spodoptera Litura Fabricius

Abstract

ABSTRACT
Entomopathogenic nematodes (EPNs) as biological agents, is consisted
Steinernema and Heterorhabditis genus. Steinernema and Heterorhabditis which
belonged to Steinernematidae and Heterorhabditidae families had closed
relationship to Xenorabdus and Photorabdus as bacterial symbionts respectively
(Smart, 1995). Types of soil moisture, temperature, and a host affect the
distribution, survivability, host finding and reproduction of EPNs. To get the
EPNs local isolates, exploration of isolates from local areas was needed. This
research was aimed to identify genus and density of EPNs on the fields of corn,
soybean and cabbage in Malang Areas and their virulence to the larvae of
Spodoptera litura. Research was conducted at laboratory of pest and disease
(Nematological Unit), Plant Protection Department, Faculty of Agriculture,
University of Brawijaya, from April to September 2012. EPNs were obtained
from corn field in Ngijo village, soybean field in Kendalpayak village, and
cabbage field in Bumiaji village. EPNs were isolated from soil samples by using
Tenebrio molitor larva. White trap method was used to attract EPNs from The
dead larva of T. molitor and the population of EPNs was counted. EPNs were
identified based on the symptoms of color changes on the cuticle and
morphological characters. In addition, virulence of EPNs was also tested on the S. litura larva. The result showed that density of EPNs was highest on cabbage field (23.264 EPNs/0.25 ml). Density of EPNs on corn field was 16.976 EPNs/0.25 ml and the lowest density was on soybean field (15.664 EPNs/0.25 ml). Based on the color changes and morphological characters of EPN, on the cabbage field, EPNs were identified as Steinernema and Heterorhabditis and the others, EPNs were identified as Steinernema. Based on the virulence test of EPNs on S. litura larva, there was significant difference between EPNs isolate of corn and others
especially for 24 hours after application.
Keywords: identification, virulence, entomopathogenic nematodes (EPNs),
Spodoptera litura