Entomopathogenic nematodes targeting the control of the corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae), under laboratory conditions

The corn leafhopper, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae), was considered a secondary pest in Brazilian corn crops. However, from 2015 onwards, there was a significant increase in its population and a high incidence of both pale and red wilt diseases. This species transmits these phytopathogens, elevating its status to a major agricultural pest. It has a high dispersal capability, significant reproductive potential, and adapts to adverse conditions, result in damage to crops by inhibiting plant growth and decreasing yield, leading to financial losses for farmers due to challenges in its control. Accordingly, the study aimed to evaluate the virulence of seven isolates of entomopathogenic nematodes belonging to the Heterorhabditis and Steinernema genera against adult D. maidis, as well as the lethal concentration (LC50), compatibility with insecticides and herbicides used in corn cultivation, and the nematode life cycle within the insect. There was no significant difference between the isolates, and they displayed a mortality rate exceeding 50%. The lethal concentration for H. amazonensis MC01 was 75 IJs adult−1, and for S. feltiae IBCB 47, it was 25 IJs adult−1. No phytosanitary product was found to be harmless to H. amazonensis MC01. The herbicide tembotrione did not affect the viability and infectivity of S. feltiae IBCB 47. The H. amazonensis MC01 and S. feltiae IBCB 47 isolates completed their life cycle in D. maidis adults, with the S. feltiae IBCB 47 isolate showing a longer life cycle than H. amazonensis MC01.