Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2002
Publication Date: N/A
Interpretive Summary: The unpleasant-smelling chemical blend that the "black locust bug" emits to defend itself was characterized as part of an effort to understand the avoidance of these brightly colored insects by bird predators. In collaboration with scientists at the Department of Biological Sciences, Illinois State University (ISU), Normal, IL, researchers at NCAUR identified the compounds emitted by these bugs when they are threatened or disturbed. Meanwhile, the ISU scientists demonstrated that native wrens and starlings which fed avidly on insects such as crickets, quickly learned to avoid the chemically defended black locust bugs. The identified chemical scent is believed to contribute greatly to this deterrence. This research adds to the general understanding of predator/prey interactions involving chemicals.
Technical Abstract: Secretions from the metathoracic glands (MTG) of the black locust bug, Lopidea robiniae (Uhler) (Heteroptera: Miridae) contained six major compounds including, (E)-2-hexenal, (E)-2-hexen-1-ol, (E)-2-octenal, (E)-2-octen-1-ol, (E)-2-heptenal, and (Z)-3-octen- 1-ol. Males and females did not differ significantly in the relative compositions of identified compounds. In feeding trials, six bird species [robin (Turdus migratorious), blue jay (Cyanocitta cristata), brown thrasher (Toxostoma rufum), killdeer (Charadrius vociferus), starling (Sturnus vulgaris), and house wren (Troglodytes aedon)]demonstrated feeding aversions towards L. robiniae, implying that black locust bugs are chemically defended. Bugs discharged the liquid contents of their MTG gland when attacked, thereby, producing a strong and distinct odor. Some birds immediately ejected bugs out of their mouth after biting them, suggesting that the MTG gland secretion was a deterrent.