|Morrison, William - Rob|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2019
Publication Date: 11/26/2019
Citation: Weber, D.C., Morrison III, W.R., Khrimian, A., Rice, K.B., Short, B.D., Herlihy, M.V., Leskey, T.C. 2019. Attractiveness of pheromone components with and without the synergist, methyl (2E,4E,6Z)-decatrienoate, to brown marmorated stink bug, Halyomorpha halys (Stål) [Hemiptera: Pentatomidae]. Journal of Economic Entomology. 113:712-719.
Interpretive Summary: The brown marmorated stink bug (BMSB) is a highly destructive pest originally from east Asia that was accidentally introduced into North America and Europe in the last two decades. For detection and monitoring of pest populations, farmers and scientists often use pheromones (volatile chemicals attracting members of the same species) and other attractants to trap pests. Researchers have identified the aggregation pheromone (produced by male bugs and attracting females, males and the immature nymph bugs), and combined it with another stink bug’s pheromone as a synergist for added attraction. Commercially-available lures and traps are now available for farmers. However, it is still unclear if the ratio of the two pheromone components in the commercial lures, as well as the ratio of the pheromone to the synergist, are optimized. This study, through 2-year-long field trials in Maryland and West Virginia, establishes that the bug’s attraction is relatively insensitive to the ratios of the pheromone components, and to the ratio of the pheromone mixture and its synergist. These findings are important because they give pheromone lure manufacturers, formulators, and pest managers flexibility to use more cost-efficient synthesis and trapping tactics to detect, monitor, and manage this pest. The results should be of interest to researchers, pest managers, and growers of affected crops.
Technical Abstract: The brown marmorated stink bug, Halyomorpha halys (BMSB) is attracted to its male-produced aggregation pheromone, a ~3.5:1 mixture of (3S,6S,7R,10S)- and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (SSRS and RSRS respectively), and also to the pheromone of its Asian sympatric Plautia stali, methyl (2E,4E,6Z)-2,4,6-decatrienoate (=MDT). A stereoisomeric mixture of (7R) 10,11-epoxy-1-bisabolen-3-ols (=mixed murgantiols) is used together in commercialized products with MDT because the latter is a synergist for H. halys attraction by mixed murgantiols. However, the optimal ratio for MDT combination with mixed murgantiols, and the sensitivity of bug captures to variation in ratio of the two pheromone components, has not been tested to date. Using black pyramid traps at two sites (in Maryland and West Virginia, USA), different ratios of mixed murgantiols to MDT were tested over two entire seasons. Also, captures using various ratios of the two active pheromone stereoisomers were undertaken in month-long trials with and without MDT. Results showed that adult and nymphal captures were relatively insensitive to the ratio of synthetic pheromone (mixed murgantiols) to MDT, as long as each was present in the trap. Captures of adults and nymphs were responsive to the lure loading of the SSRS isomer, but relatively insensitive to levels of the minor component, RSRS. The relative insensitivity of BMSB to these attractant ratios gives flexibility to development of more cost-efficient synthesis and trapping as well as other semiochemical-based management tactics.