Entomopathogenic nematodes (Steinernema and Heterorhabditis) can control many economically important pests, and are generally applied in aqueous suspension with agricultural spray equipment or irrigation systems. We show that these nematodes are more effective when applied in their infected-host cadavers than when applied in aqueous suspension. Relative to application in aqueous, laboratory studies have indicated application of infected cadavers can result in superior nematode dispersal, infectivity and survival. In two greenhouse experiments, we compared the efficacy of entomopathogenic nematodes applied in aqueous suspension with application in infected cadavers. One experiment targeted the black vine weevil, Otiorhynchus sulcatus (F.) with Heterorhabditis bacteriophora Poinar (Oswego strain), and the other targeted the diaprepes root weevil, Diaprepes abbreviatus (L.) with Heterorhabditis indica Poinar, Karunakar & David (Hom1 strain). On all sample dates, survival of D. abbreviatus was lower in the infected cadaver treatment than the aqueous applications and all nematode applications caused reduced survival relative to the untreated control. In the O. sulcatus experiment, the cadaver treatment caused lower insect survival than the aqueous treatment at the first sample date, and was the only treatment causing lower survival than the control on all sample dates.
Species 1: Rhabditida Heterorhabditidae Heterorhabditis bacteriophora (Entomopathogenic nematode)
Species 2: Coleoptera Curculionidae Otiorhynchus sulcatus (black vine weevil)
Species 3: Coleoptera Curculionidae Diaprepes abbreviatus (Diaprepes root weevil)
Keywords: entomopathogenic nematodes, formulation
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