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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #320063
Title: Efficacy of Steinernema carpocapsae plus fire gel applied as a single spray for control of the lesser peachtree borer, Synanthedon pictipes

Author
item Shapiro Ilan, David
item Cottrell, Ted
item MIZELL, RUSSELL - University Of Florida
item HORTON, DAN - University Of Florida

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2015
Publication Date: 12/12/2016
Citation: Shapiro-Ilan, D.I., Cottrell, T.E., Mizell, R.F., Horton, D.L. 2016. Efficacy of Steinernema carpocapsae plus fire gel applied as a single spray for control of the lesser peachtree borer, Synanthedon pictipes. Biological Control. 94:33-36.

Interpretive Summary: Nematodes are small round worms. Beneficial nematodes (also called entomopathogenic nematodes) are safe environmentally friendly bio-insecticides. These nematodes are usually applied to soil to control a wide variety of economically important insect pests. Aboveground application of beneficial nematodes is hindered by the nematodes’ sensitivity to UV radiation and desiccation. In prior research, the ability of a fire gel (Barricade®) to protect nematodes from harmful UV and desiccating conditions was demonstrated. The fire gel and nematodes were applied together to control the lesser peachtree borer. The lesser peachtree borer is a major pest of stone fruit; larvae attack trees aboveground by tunneling into the trunk and scaffold limbs. One drawback to the approach is that two applications must be made (first nematodes are applied followed by the fire gel); furthermore, the previous experiments did not compare nematode application to the existing standard chemical insecticide. Therefore, the objectives of this study were to 1) determine if a diluted rate of fire gel can protect nematodes when applied as a single spray, and 2) compare the efficacy of nematode applications with the chemical insecticide, chlorpyrifos. Experiments were conducted in a peach orchard in Quincy, Florida in 2013 and 2014. Treatments were applied to trees infested with lesser peachtree borer. Results indicated that the beneficial nematodes (called Steinernema carpocapsae) and Barricade® can be applied as a single spray, and in our experiments the treatment was at least as effective as the chemical standard. We conclude that beneficial nematodes mixed with Barricade® firegel can be a potent combination for controlling aboveground insect pests.

Technical Abstract: The efficacy of aboveground applications of entomopathogenic nematodes (Heterorhabditis spp. and Steinernema spp.) can be severely limited by the nematode’s susceptibility to UV radiation and desiccation. The lesser peachtree borer, Synanthedon pictipes, a major pest of stone fruit; larvae attack trees aboveground by tunneling into the trunk and scaffold limbs. In previous research, S. carpocapsae, caused high levels of S. pictipes mortality when a sprayable fire gel (Barricade®) was applied on top of the nematode application as a protectant. One drawback to the approach is that two applications must be made (first nematodes are applied followed by the fire gel); furthermore, the previous experiments did not compare nematode application to the existing standard chemical insecticide. Therefore, the objectives of this study were to 1) determine if a diluted rate of fire gel can protect nematodes when applied as a single spray, and 2) compare the efficacy of nematode applications with the chemical insecticide, chlorpyrifos. The experiment was conducted in a peach orchard in Quincy, Florida in 2013 and 2014. Treatments included: 1) chlorpyrifos, 2) S. carpocapsae applied in aqueous suspension only or 3) with a full rate (approximately 4% applied separately) or 4) 2% Barricade® (applied with nematodes in a single spray), and 5) a non-treated control. The treatments were applied post-harvest (in the fall) to S. pictipes-infested bark wounds; S. pictipes survival was assessed 8 (2013) or 14 (2014) d post-application. Results indicated that S. carpocapsae and Barricade® can be applied as a single spray, and in our experiments the treatment was at least as effective as the chemical standard.