ARS | Publication request: "hoplia Equina (Coleoptera: Scarabeidae) and Nontarget Capture Using 2-Tetradecanone-Baited Traps"

Submitted to: Environmental Entomology
Publication Acceptance Date: February 5, 2004
Publication Date: April 5, 2004
Citation: Weber, D.C., Robbins, P.S., Averill, A.L. 2004. "hoplia Equina (Coleoptera: Scarabeidae) And Nontarget Capture Using 2-Tetradecanone-Baited Traps". Environmental Entomology.

Interpretive Summary: Scarab grubs are increasingly important soil insect pests in cranberry bogs. Bog renovation or in some cases summer flooding, both very costly, are the only effective controls; pesticides are not registered. A promising alternative is to use the newly-discovered sex pheromones to disrupt the mating of the adults, which are beetles active above ground for a limited part of the growing season. Using the sex pheromone of the scarab pest Hoplia equina, we investigated the effects of trap height, color, pheromone dose, and age of the pheromone lure on male beetles that were attracted and captured. We optimized trap characteristics to catch the maximum pest numbers while minimizing effects on beneficial insects such as bees that are attracted to certain trap designs. Insect pollinators, including honeybees, native bumblebees and native solitary leafcutting bees, are essential for pollinating cranberries and many other crops, and the flight period for Hoplia is during cranberry bloom, making pollinator protection an essential consideration. Color of traps (white, yellow, green, blue, red, black) did not affect pest capture, but significantly influenced capture of nontarget insects, including pollinators. A green bucket trap with opening at 20 cm above the ground and a pheromone dose of 600 micrograms was the optimal design for pest capture, minimal bee capture, and low failure rate. The low-cost capture of over 50,000 beetles on a 4-acre infested commercial bog in Massachusetts with this very selective trap design shows the potential for mass-trapping to suppress established infestations of scarab grubs in cranberries. This information will be used by researchers, extension agents, commercial scouts, and growers of cranberries. It will add to the growing body of research on development of selective traps for pest management.

Technical Abstract: Using bucket traps baited with the single-component pheromone 2-tetradecanone, we investigated the effect of trap height, color, pheromone load and lure ageing, on capture of Hoplia equina LeConte, an important scarab beetle pest of cranberries in Massachusetts, and on nontarget arthropods including pollinators. H. equina captures were inversely related to height of traps over the four heights tested (0, 20, 60 and 100 cm). H. equina captures increased with increasing pheromone load over the doses of 0, 100, 300, and 600 micrograms , but captures at the highest load, 1000 micrograms, were not significantly different from 300 or 600 micrograms. H. equina was strongly diurnal, with a flight period spanning about 6 weeks starting in mid-June. Vane color of traps (white, yellow, green, blue, red, black) did not affect H. equina capture, but significantly influenced capture of nontargets, including pollinators. A bucket trap with opening at 20 cm, and green (or red) baffles, baited with 600 micrograms of 2-tetradecanone, was the optimal design for high H. equina capture, low nontarget capture, and low failure rate. The low-cost capture of over 50,000 H. equina on a 2.4-hectare commercial bog in Massachusetts with this very selective lure-trap combination points to the potential feasibility of mass-trapping to suppress established infestations of Hoplia equina.