Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2016
Publication Date: 10/15/2016
Citation: Ohler, B.J., Guedot, C., Zack, R.S., Landolt, P.J. 2016. Aggregation of Thaumatomyia glabra (Diptera: Chloropidae) males on Iris spp. flowers releasing methyl anthranilate. Environmental Entomology. 45(6):1476-1479. Interpretive Summary: Aphids are key pests of numerous vegetable crops, and are vectors of damaging plant pathogens. Predators and parasites can provide valuable biological control of pest aphids under appropriate management. Researchers at the USDA-ARS Yakima Agricultural Research Laboratory in collaboration with a Washington State University scientist, studied aggregations of males of Thuamatomia glabra, a fly that is a predator of root aphids, to determine if fly aggregations on iris flowers occur in response to a chemical attractant. They found that variegated iris flowers, and not German iris flowers, produce methyl anthranilate as a floral scent, which attracts the males of T. glabra. This suggests a means of sampling populations of the fly with a chemical lure, and possibly of attracting the fly onto crops to better manage pest aphids.
Technical Abstract: Aggregations of Thaumatomyia glabra (Diptera: Chloropidae) were observed on flowers of Iris pallida (Asparagales: Iridaceae) while no T. glabra were observed on nearby Iris germanica flowers. Sampling of T. glabra on I. pallida flowers revealed the presence of males only. In a previous study, T. glabra males were attracted to methyl anthranilate. We found methyl anthranilate in extracts of I. pallida flowers on which T. glabra aggregated, but not in extracts of I. germanica flowers. These studies suggest that I. pallida flowers may attract T. glabra males to aggregate because they release the known attractant, methyl anthranilate, and that I. germanica flowers may not be attractive because they do not release methyl anthranilate.