Author
Shapiro Ilan, David | |
Wright, Starker | |
TUTTLE, ARTHUR - University Of Massachusetts | |
COOLEY, DANIEL - University Of Massachusetts | |
Leskey, Tracy |
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/30/2013 Publication Date: 10/3/2014 Citation: Shapiro Ilan, D.I., Wright, S.E., Tuttle, A.F., Cooley, D.R., Leskey, T.C. 2013. Using entomopathogenic nematodes for biological control of plum curculio, Conotrachelus nenuphar: Effects of irrigation and species in apple orchards. Biological Control. 67:123-129. Interpretive Summary: The plum curculio is a major pest of stone and pome fruit (e.g., apples, pears, peaches, cherries, etc.). Beneficial insect-killing nematodes (also called entomopathogenic nematodes) are safe environmentally friendly bio-pesticides that are used to control a variety of important pests. These nematodes are capable of killing the ground-dwelling stages of plum curculio and may be incorporated into an integrated management strategy. Two significant questions that must be addressed prior to implementation are: 1) which nematode is most effective in suppressing the target pest under field conditions? and 2) what is the impact of various irrigation levels on field efficacy? We addressed these questions by comparing the efficacy two nematodes, Steinernema riobrave and Steinernema feltiae and an untreated control, at three irrigation levels 0, 1 and 6 irrigation events over a two period post-application. The experiments were conducted at two field sites (apple orchards in Kearneysville, WV and Belchertown, MA) in 2011 and 2012. Relative to the untreated check, the nematode called S. riobrave did the best causing 85.0% & 97.3% control of plum curculio in 2011 and 2012 in MA (respectively) and 100% control in WV both years, whereas the nematode called S. feltiae caused 0% and 84.6% control in 2011 and 2012 (respectively) in MA, and 78.2 and 69.7% control in WV. Irrigation did not have a significant effect on plum curculio suppression at both sites and in both years of the experiments. The lack of irrigation effects is an unusual finding for field applications using beneficial nematodes, and may have been due to the level of precipitation and a high water-holding capacity in the field soils tested. The results of this study have positive implications for the potential of incorporating beneficial nematodes into a plum curculio management program. Technical Abstract: The plum curculio, Conotrachelus nenuphar, is a major pest of stone and pome fruit. Entomopathogenic nematodes (Steinernema spp. and Heterorhabditis spp.) are virulent to ground-dwelling stages of C. nenuphar. Two significant questions that must be addressed prior to implementation are: 1) which nematode is most effective in suppressing the target pest under field conditions? and 2) what is the impact of various irrigation levels on field efficacy? We addressed these questions by comparing the efficacy two nematodes, Steinernema riobrave and Steinernema feltiae (two nematodes that showed the highest virulence in prior lab assays and field trials) and an untreated control, at three irrigation levels 0, 1 and 6 irrigation events over a two period post-application. The experiments were conducted at two field sites (apple orchards in Kearneysville, WV and Belchertown, MA) in 2011 and 2012. Relative to the untreated check, S. riobrave caused 85.0% & 97.3% control in 2011 and 2012 in MA (respectively) and 100% control in WV both years, whereas S. feltiae caused 0% and 84.6% control in 2011 and 2012 (respectively) in MA, and 78.2 and 69.7% control in WV. Thus, overall S. riobrave was found to be superior to S. feltiae in suppression of C. nenuphar. Irrigation did not have a significant effect on C. nenuphar suppression at both sites and in both years of the experiments. The lack of irrigation effects is an unusual finding for field applications using entomopathogenic nematodes, and may have been due to the level of precipitation and a high water-holding capacity in the field soils tested. The results of this study have positive implications for the potential of incorporating entomopathogenic nematodes into a C. nenuphar management program. |