ABSTRACT
The parasitic efficiency of native entomopatogenic nematodes, Steinernema glaseri (Steiner, 1929) and Heterorhabditi indica Poinar, Karunakar & David, 1992 (IBCB–n5) were evaluated against eggs and larvae of the Migdolus fryanus (Westwood, 1863) under laboratory conditions. Eggs of the insect were exposed to suspensions of Infective Juveniles (JI) of H. indica in 2 concentrations, 60 and 600 JI/egg. Three treatments, each one with 3 replicates, with 5 eggs each, were conducted. The nematode did not differ significantly from the control, but it penetrated the eggs and reduced its viability. S. glaseri and H. indica (600 JI/larva) were also evaluated against the newly hatched larvae of M. fryanus. Four replicates per treatment were used, each one containing 5 larvae. In this case both nematodes resulted in high mortality. S. glaseri caused 100% of mortality and H. indica 80%. There were no significant differences between the nematodes. S. glaseri and H. indica in 2 concentrations (400 and 800 JI/larva) against the last stage of the M. fryanus larvae were also evaluated. Seven replicates per treatment were used, each one with 3 larvae. No significant differences between the concentrations for both nematodes were detected. However, H. indica was more efficient causing significant higher mortality among larvae (76.43 and 71.57%, respectively), in the two concentrations. H. indica and S. glaseri showed to be pathogenic to eggs and larvae of M. fryanusi. These nematodes seem to have high potential as agents for the control of M. fryanus in sugarcane fields, in São Paulo state, Brazil.
KEY WORDS
Steinernema glaseri
;
H. indica
; sugarcane; biological control
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