Submitted to: International Insects Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/7/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: White grubs are serious pests of turf, nursery and field crops throughout the world, and are becoming an increasing problem as the persistent pesticides used in the past for their control are degrading and no longer restricting scarab populations. New chemistry insecticides are more environmentally friendly, but require prophylactic treatments and do not always provide adequate suppression of grubs. Few biological control organisms are available for use against these pests, and entomopathogenic nematodes have appeared to be among the most promising agents. Nematodes have historically been associated with scarab larvae, and there have been many attempts to use them for white grub control. However, the effects have been spotty. Over 60 years ago, efforts utilized Steinernema glaseri which was originally isolated from Japanese beetle, Popillia japonica, larvae. However, lack of understanding of the synergistic bacteria led to their loss in mass production and resulted in ineffective nematodes. In the mid 80s, attempts were made to get S. carpocapsae to control grubs. It became obvious that no one nematode was going to be effective against all pests and that white grubs were a diverse and difficult target. Recent research indicated that only S. glaseriand S. kushidai and heterorhabditids are most effective at killing scarab larvae. Studies at Wooster, Ohio have shown a wide disparity in control of white grubs by Heterorhabditis strains and species, with H. zealandica being the most effective. In addition, certain white grubs (P. japonica, Cyclocephala spp. and Exomala orientalis) are all equally susceptible to nematodes, but others (European chafer, Rhizotrogus majalis) are almost refractive to all species and strains tested.