|SPEARS, LORI - Utah State University|
|LOONEY, CHRISTOPHER - Washington Department Of Agriculture|
|KOCH, JONATHAN - University Of Hawaii|
|RAMIREZ, RICARDO - Utah State University|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2016
Publication Date: 7/13/2016
Citation: Spears, L.R., Looney, C.N., Ikerd, H.W., Koch, J.B., Griswold, T.L., Strange, J.P., Ramirez, R.A. 2016. Pheromone lure and trap color affects bycatch in agricultural landscapes of Utah. Environmental Entomology. 45:1009-1016.
Interpretive Summary: Insect traps are important tools for monitoring pest populations in surveys and integrated pest management (IPM) programs. Traps can help detect invasions by novel pest species, the onset of seasonal pest activity, determine the range and intensity of pest infestations, and track changes in pest populations, all which help inform decision making for pest management. These traps, however, catch many insects that are not intended to be captured, and we term this bycatch. Many of the non-target insects that are killed are beneficial, including pollinators and predatory lady bird beetles. We investigated the effects of changing trap color and the chemicals in the traps used to lure the insects, on the number of beneficial insects caught in the traps. We placed the different kinds of traps in corn and alfalfa fields and monitored the bycatch over a growing season. We found that both trap color and chemical lure had significant effects on the amount of bycatch in the traps. We discuss changes in trap design and deployment that may minimize bycatch and discuss future work to further reduce harm to beneficial insects.
Technical Abstract: Aerial traps, using combinations of color and attractive lures, are a critical tool for detecting and managing insect pest populations. Yet, despite improvements in trap efficacy, collection of non-target species (“bycatch”) plagues many insect pest surveys. Bycatch can influence survey effectiveness by reducing the available space for target species and increasing trap screening time, especially in areas where thousands of insects are captured as bycatch in a given season. Additionally, bycatch may negatively impact local non-target insect populations, including beneficial predators and pollinators. Here, we tested the effect of pheromone lures on bycatch rates of Coccinellidae (Coleoptera), Apoidea (Hymenoptera), and non-target Lepidoptera. Multicolored (primarily yellow and white) bucket traps containing a pheromone lure for capturing one of three survey target species, Spodoptera litura (Fabricius), S. littoralis (Boisduval), or Helicoverpa armigera (Hübner), were placed in alfalfa and corn fields, and compared to multicolored traps without a pheromone lure. All-green traps with and without H. armigera lures were employed in a parallel study investigating the effect of lure and trap color on bycatch. Over 2,600 Coccinellidae representing seven species, nearly 6,400 bees in 57 species, and more than 9,000 non-target moths in 17 genera were captured across 180 traps and seven temporal sampling events. Significant effects of lure and color were observed for multiple taxa. In general, non-target insects were attracted to the H. armigera lure and multicolored trap, but further studies of trap color and pheromone lure specificity are needed to better understand these interactions and to minimize non-target captures.