Unfortunately, very little is known of the biology of Elaphidiini. As nearly all of them are nocturnal as adults, over 95% are most commonly taken at lights and thus are collected without any host or association records. Their abundance at lights can be remarkable. In western México, 13 nights of collecting at one illuminated roadside sign produced 1700 specimens of longhorn beetles. Elaphidiines represented 63% of all specimens and 35% of all species (Chemsak, et al., 1988)!
The following is a generalized life cycle of elaphidiines (summarized and generalized from Solomon, 1995). Adults emerge in spring or summer, mate, and females lay the eggs in notches in bark of dead branches. The larvae either feed for some time under the bark, or immediately enter the wood, feeding and developing within the heartwood. Larval development most often takes one to three years, correlated with the size of the beetle. A pupal cell is created in the region between the bark and sapwood at the end of larval development. Pupation occurs in either late summer to early fall, or early spring. Adults do not emerge until spring or summer, regardless of when pupation occurs.
Adults of most species feed very little or not at all, but few references to feeding behavior exist. Specimens in some genera (Anelaphus Linsley, Elaphidion, Parelaphidion Skiles, Enaphalodes Haldeman) are attracted in great numbers to brown sugar bait solutions (Lingafelter and Horner, 1993), indicating their natural attraction to sap flows or other natural high-sugar sources of nutrition. Adults of at least two diurnal genera including Tropimerus Giesbert (Giesbert, 1987), and Stenosphenus Haldeman (Giesbert and Chemsak, 1989) are commonly encountered on flowering trees. Aneflomorpha tenuis (LeConte) adults have been reported feeding in large numbers on Karwinskia blossoms (Turnbow and Wappes, 1981). Adults of Anelaphus albofasciatus Linell have been reported feeding on new growth of Opuntia (Raske, 1972).
Twig-girdling--cutting off the flow of nutrients or chemicals to a portion of the plant, thereby killing part of it--is a behavior most commonly associated with the distantly related Onciderini. In this group the girdling is performed by the adult female prior to oviposition. It has also been noted to occur in at least three genera of Elaphidiini including Psyrassa Pascoe (Champlain, et al., 1925); Aneflomorpha Casey (Craighead, 1923); and Anelaphus Linsley (Craighead, 1950), although in these groups the girdling is internal and done by the larvae.
Larval hosts are not known for most species. Many taxa in the southern United States and México are associated with leguminous plants of the genera Prosopis and Acacia (Linsley, 1963, and references cited therein). Eucalyptus is the primary host for the Australian fauna (phoracanthine group), but other reported hosts include Acacia and Angophora (Wang, et. al., 1996).
Text by Steven W. Lingafelter Design and Format by: Natalia J. Vandenberg, Last Updated: July 30, 2001. Based on a site created by Jennifer E. Fairman June 15, 1997. |