Parasitism of entomophilic nematodes on the sugarcane rootstalk borer, Diaprepes abbreviatus (L.) (Coleoptera:Curculionidae), larvae

Abstract

Ten greenhouse experiments tested the effectiveness of the entomophilic nematodes Steinernema feltiae Filipjev, S. glaseri Weiser, and S. bibionis Bobien against larvae of the sugarcane rootstalk borer, Diaprepes abbreviatus (L.). S. feltiae caused mortality to 12- to 16-week-old D. abbreviatus larvae at population densities of 1,000 to 3,000 nematodes/ 300 cm³ of soil. Four hundred S. glaseri or S. bibionis also caused significant mortality of the grubs. An increase of 4,000 to 40,000 S. glaseri/300 cm³ of soil increased mortality of the grubs. S. bibionis infectivity decreased with time, and high rates of mortality of the infective juveniles were recorded under laboratory conditions. When grubs were placed in petri dishes in direct contact with the nematodes before placing the infected grubs in soil, the mortality was independent of the density or nematode species used. These results demonstrated the effectiveness of the entomophilic nematodes and their potential for biocontrol of D. abbreviatus