Redcoat Seedbug
Melanopleurus belfragei
Photographed along Camp Creek, Maricopa Co., Arizona, USA, September 2008. Host plant is waterweed, Baccharis sergiloides. Identification of the bug made possible by Merrill Sweet with the aid of v. belov.
Lygaeidae -- Seed Bug Family
Waterweed / Desert Baccharis
Several species of brightly marked seed bugs can be found on blooming plants in the Sonoran Desert. Composites, family Asteraceae, are frequent hosts; this is the family of sunflowers and daisies. Bugs have piercing-sucking mouthparts that they insert into the developing buds and seed heads. Through a channel inside the straw-like proboscis they with draw liquid food. They may inject some digestive enzymes to assist this process. Seeds that have been penetrated by the bugs' feeding may not develop properly or germinate. The bright color is indicative of a warning coloration - indeed picking these bugs with fingers will cause the bugs to release a sharp, pungent mixture that probably deters birds and lizards from eating these bugs. Apparently there are about nine species of Melanopleurus in North America north of Mexico.
Developing seeds within the flower heads of Burrobush are among the food-plants used by redcoats. Superior, Pinal Co., Arizona. 24 Sept. 2017.