Explanation of Names
Trirhabda geminata Horn 1893
Dry chaparral, desert scrub, and coastal sage scrub, where Encelia (Brittlebush) occurs.
Larval host plants are species of Encelia.
In the inland desert portions of the range of T. geminata
, the host species are E. farinosa
, E. virginensis(1)
In coastal adjacent southern California, E. californica
is the host plant...which seems to often be overlooked in many references, but is mentioned in in O'Brien & Atsatt (1982) [at bottom of 1st page] and corroborated by many BugGuide posts.
A photo of this species can be found in Evans & Hogue (2)
(see Plate 272).
Blake D.H. (1931) Revision of the species of beetles of the genus Trirhabda
north of Mexico. Proc. U.S. Nat. Mus. 79(2):1-36 (Full text
Blake D.H. (1951) New species of chrysomelid beetles of the genera Trirhabda
. Journal of the Washington Academy of Sciences, 41:324-328. (Full text
Hogue S.M. (1970) Biosystematics of the genus Trirhabda
LeConte of America north of Mexico (Chrysomelidae: Coleoptera). Ph.D. dissertation, University of Idaho, 212 pp.(1) The most complete reference to date.
Kunze, A., Aregullin, M., Rodriguez, E., & Proksch, P. (1996). Fate of the chromene encecalin in the interaction of Encelia farinosa
and its specialized herbivore Trirhabda geminata
. J. Chem. Ecol. 22:3, 491-498. (Abstract
Sorensen, M. A., J. A. Bethke, and R. A. Redak (2010). Potential Host Plants of Trirhabda geminata
(Coleoptera: Chrysomelidae) : Impacts on Survival, Development, and Feeding. Environmental Entomology 39(1):159-163. Abstract
O'Brien, P. Y. & P. R. Atsatt. (1982). Life history and general bionomics of Trirhabda sericotrachlya
Blake (Coleoptera: Chrysomelidae) in southern California. Pan-Pacific Entomologist 58 (2) 139-152. (Full text