Population densities of lepidopteran pests in selected cranberry cultivars in Wisconsin

Authors: MCMAHON, ERIN - University Of Wisconsin; Steffan, Shawn; GUEDOT, CHRISTELLE - University Of Wisconsin

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2016
Publication Date: 6/1/2017
Publication URL: http://handle.nal.usda.gov/10113/5700673
Citation: McMahan, E.E., Steffan, S.A., Guedot, C. 2017. Population densities of lepidopteran pests in selected cranberry cultivars in Wisconsin. Journal of Economic Entomology. 110(3):1113-1119. doi: 10.1093/jee/tow274.

Interpretive Summary: In agriculture, host plant resistance represents an innate form of pest control for a crop. Too often, it is not exploited as a pest control tactic because plant breeding efforts generally focus on yield and other production priorities. Here, we report that two common cranberry varieties, ‘Stevens’ and ‘GH-1’ are significantly resistant to the cranberry fruitworm, the top pest of Wisconsin cranberries. This effect derived from non-preference among ovipositing female and/or antibiosis among the larvae. Together, these two varieties exhibited reduced berry infestations (compared to other common varieties such as ‘Ben Lear’ and ‘Mullica Queen’). Conversely, another pest species, the sparganothis fruitworm, appeared to prefer ‘Stevens’ and ‘GH-1,’ as evidenced by higher trap-catch among adult males within these varieties. Altogether, this information provides growers with information as to which varieties may be best to deal with their local pest populations. Impact: Integrated pest management (IPM) relies on multiple control tactics to achieve pest suppression, and host plant resistance is an important tool in the IPM “tool box.” The information reported herein represents the first steps in characterizing the resistance of cranberry varieties to specific pest species. This will impact future breeding efforts, as well as grower decision-making with regard to bed establishment.

Technical Abstract: Host plant resistance, an important strategy of integrated pest management (IPM), was examined in the American Cranberry, Vaccinium macrocarpon Aiton (Ericaceae). Despite the pressure for cranberry growers to reduce pesticide usage, host plant resistance is not used to help manage insect populations. This study measured field population densities of the three most economically important pest insects in Wisconsin: cranberry fruitworm (Acrobasis vaccinii Riley), sparganothis fruitworm, (Sparganothis sulfureana Clemens), and blackheaded fireworm (Rhopobota naevana Hübner) in five different cranberry varieties, i.e. Stevens, Ben Lear, GH-1, Mullica Queen, and HyRed. Population densities of male moths of all three species were assessed using pheromone traps in beds of the different cranberry varieties in commercial marshes in central Wisconsin. For each variety, damaged cranberries were collected, and the number of damaged berries and larvae feeding within berries were compared among varieties. Adult populations of sparganothis fruitworm were significantly lower in beds of Ben Lear and Mullica Queen than in beds of Stevens and GH-1, but adult populations of cranberry fruitworm and blackheaded fireworm were not different among varieties. More than 99% of larvae collected were cranberry fruitworm. Mullica Queen and Ben Lear had significantly more damaged berries than Stevens or GH-1, and had more larvae than GH-1. Our findings provide evidence of different levels of resistance in common cranberry varieties that can inform future plantings and breeding programs.