PROC. ENTOMOL. SOC. WASH. 103(2), 2001, pp. 403-408 IN CIS ALIA HENRICI (GROTE AND ROBINSON) (LEPIDOPTERA: LYCAENIDAE) REARED ON REPRODUCTIVE AND NON-REPRODUCTIVE TISSUES OF THREE DIFFERENT PLANT SPECIES Gordon F. Pratt and Cecilia L. Pierce Department of Entomology, University of California, Riverside, CA 92521, U.S.A. Abstract. — Larvae of the small hairstreak butterfly, Henry's Elfin (Incisalia henrici), feed on a wide variety of plants and plant parts. The larvae of this Elfin along the eastern coastal plain feed on young leaves and flowers of hollies (Ilex sp.). Throughout much of the interior southeast the major food plant is believed to be flowers, flower buds, and young leaves of redbud (Cercis canadensis). While in the northern part of its range larvae have been found feeding on the fruits of a variety of plants including blueberries (Vac-cinium sp.) and cherries (Prunus sp.). The effects of food plant species (hollies, redbud, and cherry) and plant parts (leaves vs. flowers) were studied on percent survival, pupal weights, and development times. Larvae survived well on the different test host plants and host plant parts. The Ilex reared pupae, despite being reared on the natal host, were significantly lower in weight than pupae of larvae reared on the other two plant species. Larvae reared on Cercis flowers and flower buds performed best in all categories. We conclude the subspecies utilizing Ilex as a food plant did not become adapted to this plant because larvae perform better than on other plants, but due to other variables such as perhaps the availability or abundance of plants in the habitat. Key Words: Lycaenidae, hairstreaks, host races, Theclinae, foodplant effects It has been suggested that some lycaen-and Pratt 1989). For instance some lycaenid ids, particularly eumaeine hairstreaks, genera, such as Celastrina that feed on a which feed on a broad variety of plants, are broad variety of plants, exhibit both mo-able to do so because they specialize on the nophagous species and generalists with lo-flowers and fruits of their hosts (Pratt and cal specialization in food plants as geo-Ballmer 1991). Presumably these reproduc-graphic races (Pratt et al. 1994). In contrast tive tissues exhibit a higher proportion of some species, such as Strymon melinus amino acids and protein to that of alkaloids Hubner, not only feed on a broad variety of and other secondary plant compounds plants locally, but on a variety of plant parts (Chew and Robbins 1984, Pratt and Ball-as well (Ballmer and Pratt 1989). mer 1991). Specializations to multiple food Henry's Elfin, Incisalia henrici (Grote plants can be either as separate species or and Robinson), is an interesting model spe-by local adaptations of a single species that cies to test larval adaptations, since it feeds is capable of feeding on a broad variety of on the flowers, fruits, and leaves of a broad plants (Fox and Morrow 1981). Lycaenid variety of plants and exhibits a number of butterflies fit both types from species with geographic races (Pavulaan 1998, Gatrelle restricted host ranges to generalists that 1999). It uses six host families in nature: have become locally specialized (Ballmer Aquifoliaceae [Ilex cassine L., /. opaca
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