Colorado potato beetle, Leptinotarsa decemlineata: This is an economically important pest of potatoes with more than 40 species have been reported from North America. The larvae of this beetle are voracious feeder of potato leaves costing hundreds of millions of dollars for pesticide control and yield loss each year in the United States. Entomopathogenic nematodes as biological control agents could provide an alternative to chemical pesticides in management of this noxious pest. In a laboratory bioassay, four species of entomopathogenic nematodes including Steinernema carpocapsae, S. feltiae, Heterorhabditis bacteriophora, and H. megidis showed highest virulence against both larval and adult stages of the Colorado potato beetle, Leptinotarsa decemlineata at temperatures higher than 15oC when tested at the rate of 200 -2000 infective juveniles per individual of Colorado potato beetle (Trdan et al., 2009).
In another laboratory study, entomopathogenic nematode, H. marelata can cause 100% mortality of Colorado potato beetle larvae (Berry et al., 1997) but in the field, this nematode when applied twice in potato growing season can reduce only 50% population of adult Colorado potato beetles (Armer et al., 2004).
The efficacy of pesta-pelletized Steinernema carpocapsae All strain was tested against prepupal stages of Colorado potato beetle in a greenhouse (Nickle et al., 1994). Infective juveniles of S. carpocapsae were able to survive the pesta-pellet process and able to reduce over 90% emergence of adults of Colorado potato beetle.
It has been also reported that prepupal stages of Colorado potato beetle were very susceptible to different species/strains of entomopathogenic nematodes including S. carpocapsae All strain; S. carpocapsae Mexican strain; S. feltiae strain #27; S. feltiae strain #980 and Heterorhabditis bacteriophora. All these nematode species caused 100% mortality of beetle prepupae when applied in the soil at the concentration of 165 infective juveniles/cm2 (Cantelo and Nickle, 1992).
For more information, read following literature on interaction between entomopathogenic nematodes and Colorado potato beetle.
Armer, C.A., Berry, R.E., Reed, G.L. and Jepsen, S.J. 2004. Colorado potato beetle control by application of the entomopathogenic nematode Heterorhabditis marelata and potato plant alkaloid manipulation. Entomologia Experimentalis et Applicata. 111: 47-58.
Berry, R.E., Liu, J. and Reed, G. 1997. Comparison of endemic and exotic entomopathogenic nematode species for control of Colorado potato beetle (Coleoptera : Chrysomelidae). Journal of Economic Entomology. 90: 1528-1533.
Cantelo, W.W. and Nickle, W.R. 1992. Susceptibility of prepupae of the Colorado potato beetle (coleoptera, chrysomelidae) to entomopathogenic nematodes (Rhabditida, Steinernematidae, Heterorhabditidae). Journal of Entomological Science. 27: 37-43.
Nickle, W.R., Connick, W.J. and Cantelo, W.W. 1994. Effects of pesta-pelletized steinernema-carpocapsae (all) on western corn rootworms and colorado potato beetles. Journal of Nematology. 26: 249-250.
Trdan, S., Vidrih, M., Andjus, L. and Laznik, Z. 2009. Activity of four entomopathogenic nematode species against different developmental stages of Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera, Chrysomelidae. Helminthologia. 46: 14-20.