Evaluation of lepidopteran population densities in selected cranberry varieties

Host plant resistance, an important strategy of Integrated Pest Management, was examined in the American Cranberry, Vaccinium macrocarpon Ait. (Ericaceae). This study assessed field population densities of the three most economically important pest species in Wisconsin: blackheaded fireworm, Rhopobota naevana (Hübner) (Lepidoptera: Tortricidae), sparganothis fruitworm, Sparganothis sulfureana (Clemens) (Lepidoptera: Tortricidae), and cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae) in six different cranberry varieties, i.e. Stevens, Ben Lear, GH-1, Mullica Queen, Hy-Red and Pilgrim. Traps containing female sex pheromone lures for each of the three insect species were placed in the different cranberry varieties in commercial marshes in central Wisconsin. Male moths were trapped between June 13^th and August 22^nd of 2013, which included the first flight for all three species. Numbers of males were compared to determine whether differences in moth populations exist among these varieties. No significant difference in male population densities among varieties was found for blackheaded fireworm (n=5; F=0.32; P=0.8987), sparganothis fruitworm (n=5; F=1.18; P=0.3196), or cranberry fruitworm (n=5; F=2.01; P=0.0834). The lack of significant difference could be explained by the considerable variation in total moth populations among different sites. This study will be repeated in the summer of 2014, and future research will assess development rates of these insect pests on selected cranberry varieties.