Using Steinernema carpocapsae (Nematoda: Steinernematidae) in laboratory studies for control of the larger black flour beetle, Cynaeus angustus (Coleoptera: Tenbrionidae)

The larger black flour beetle (LBFB), Cynaeus angustus (Coleoptera: Tenebrionidae), thrives in cotton gin trash piles in the southern plains of Texas and can become a nuisance pest in public and private facilities. LBFB infestations have resulted in lawsuits being filed against cotton gins and owners of gin trash piles. Previous studies have shown that LBFB control with either diatomaceous earth and/or liquid spinosad treatments was ineffective, and there are no labeled insecticides for use in gin trash piles. Here, we report on studies involving the entomopathogenic nematode, Steinernema carpocapsae, as biological control agent of LBFB. These entomopathogenic nematodes have been used successfully for control of the alfalfa snout beetle, Otiorhynchus ligustici (Coleoptera: Curculionidae), in the state of New York. Using mason jars as experimental units, 500 g soil (with gin trash on top), we showed that a 2.47 billion per hectare nematode dosage significantly reduced LBFB populations and therefore confirmed the potential of this control agent. We conducted a study of the vertical distribution of nematodes when a soil profile was inoculated at different depths, and we determined to what extent the vertical distribution was affected by presence of LBFB in the soil. This study is part of an on-going effort towards development of efficient and practically feasible control/suppression of LBFB in gin trash piles.