Submitted to: Journal of Nematology
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2006
Publication Date: June 30, 2006
Citation: Lacey, L.A. 2006. Entomopathogenic nematodes for control of codling moth in apples and pears: overcoming obstacles of environment and attitude. Journal of Nematology. 38:277. Technical Abstract: Field trials of the insect-specific nematodes, Steinernema carpocapsae and S. feltiae were conducted in apple and pear orchards under a variety of conditions to determine the effects of nematode species and seasonal temperature, formulation, post-application irrigation and method of application on efficacy. Applications of one million infective juveniles (IJs) of S. carpocapsae or S. feltiae per apple tree with a backpack sprayer plus wetting agent and supplemental wetting in late summer and early fall with mean temperatures of 16.6°C and 10.3°C during the initial 24 h following treatment resulted in larval mortalities caused by S. carpocapsae of 94.4 and 58.2, respectively and 95.1% and 90.1%, respectively, due to S. feltiae. Similar tests with S. feltiae in the same location in mid-October (mean temp. 7.3°C) using cocooned sentinel larvae in logs and cardboard strips were conducted with and without: post-application wetting, wetting agent and a humectant. The highest mortality (80%) was observed in cardboard substrates receiving post-application wetting, and either wetting agent or humectant. Apple trees that were treated in late summer (mean temp. 20.1°C) with two million IJs of S. feltiae per tree using an airblast sprayer or with a hand-held lance applicator plus supplemental wetting resulted in 83 and 92% mortality in sentinel CM larvae, respectively. CM mortality under two types of irrigation, conventional over head springlers and micro-sprinklers, in a older commercial pear orchard that was treated with one billion IJs/acre of S. carpocapsae using an airblast sprayer resulted in nearly 100 % mortality in sentinel larvae. The addition of mulches to orchards improved larvicidal activity of S. carpocapsae and S. feltiae against cocooned CM larvae.