The objective of this research was the ethological characterization of entomopathogenic nematode populations of the genus Heterorhabditis as candidates for the biological control of the white grub (Premnotrypes vorax), a pest of economic importance in pot ninguno

Abstract

ABSTRACT

The objective of this research was the ethological characterization of entomopathogenic nematode populations of the genus Heterorhabditis as candidates for the biological control of the white grub (Premnotrypes vorax), a pest of economic importance in potato (Solanum tuberosum) crops. The reproductive potential, displacement capacity, relative humidity and host range of fifth instar larvae of P. vorax were evaluated. In the reproductive potential, it was determined that a P. vorax larva with an average weight of 62 mg can produce 6.5x10³ IJs from isolate CC03 and 66.5x10³ IJs from isolate CCC01. Vertical displacement studies established that 45.6% of the IJs were displaced up to 5 cm depth, 30.6% up to 10 cm and 16.1% up to 15 cm. Relative humidity of 15% showed to be the most efficient for the displacement of NEPs of isolates CC01 and CC03 with 24.9 IJs/larva of Galleria mellonella. The 11% humidity showed an average of 13.8 IJs/larva and the 5% humidity showed 9.3 IJs/larva; which shows that the higher the percentage of humidity of the substrate, the greater the number of IJs per larva, and the opposite, when the substrate tends to be drier, it inhibits the action and displacement of the NEPs. The two isolates were shown to be highly pathogenic also for other pests such as Tecia solanivora and Symestrichema tangolias.