10 JOURNAL OF THE LEPIDOPTERISTS' SOCIETY SPICEBUSH, LlNDERA BENZOIN, A LITTLE KNOWN FOODPLANT OF PAPILlO GLAUCUS (PAPILIONIDAE) J. MARK SCRIBER, ROBERT C. LEDERHOUSE, AND LORRAINE CONTARDO Department of Entomology, Cornell University, Ithaca, New York 14850 Papilio glaucus L., the eastern tiger swallowtail, is one of the most polyphagous of all Papilionidae, yet documented records of it utilizing lauraceous foodplants are rare. Teitz (1954, 1972) is the only author who reports Lindera benzoin (L.), but we have been unable to locate any such original record from the references he listed. Sassafras albidum ( Nutt.) also is recorded by Edwards (1884), French (1885), Scudder (1889) and Teitz (1954, 1972). These authors have apparently cited either Stauffer (1862) or personal communication of John Akhurst. The larval description (" .... the larva of turnus (which was taken from Sassafras) was pea-green above with a yellow edging, beneath purplish­ brown.") suggests that Stauffer's record is based on a mistaken P. troilus larva. Akhurst records a P. glaucus female ovipositing on Sassafras branches while confined in a box. Five freshly hatched first instal' Papilio glaucus larvae were discovered on leaves of spicebush, Lindera benzoin of the Lauraceae, on Snyder Hill near Thomas Road, Town of Caroline, Tompkins County, New York. This same stand of spicebush yielded P. troilus L. larvae the previous year, although none were found there in 1973. In addition to the P. glaucus larvae found on June 25, 1973, another fertile egg was dis­ covered on July 11. For comparisons with growth rates on other food­ plants (Scriber, in prep.), field growth rates of larvae were observed on spicebush until they reached the late stages of the final instal'. At this point they were taken into the laboratory, and weighed. In our bioclimatic control chambers, we have successfully reared P. glaucus from the Ithaca, New York area from the first instar through pupation on L. benzoin and S. albidum. Also, first instar larvae obtained from eggs laid on Prunus serotina Ehrh. were placed on spicebush and sassafras in the field, where they successfully completed development. When placed in a large walk-in screened cage (16' X 20' X 15') stocked with various transplanted deciduous saplings, P. glaucus females ovi­ posited on Lindera benzoin and Sassafras albidum, as well as on its other more widely recognized foodplants, such as Liriodendron tulipifera L. and Magnolia virginiana L. (Magnoliaceae), Prunus serotina (Rosaceae) and Fraxinus americana L. (Oleaceae). Other plant species present in VOLUME 29, NUMBER 1 11 the cage, but not utilized by P. glaucus for oviposition, included Pasti1Ulca sativa L. (Umbelliferae), Dictamnus Fraxinella Pers. (Rutaceae), Rhamnus catharlica L. (Rhamnaceae) and Syringa vulgaris L. (Oleaceae). There are presently a minimum of 26 species of Papilionidae known to utilize the Lauraceae as larval foodplants, including the genera Eurytides, Protographium, Graphium, and Papilio (Scriber, 1973). In the New World the two primary sections of Papilio that feed on the Lauraceae are (1) the Neotropical P. homerus and P. scamander groups which appear to be polyphagous and (2) the North American P. glaucus and P. troilus groups. Both groups have similar green larvae, bearing large mimetic thoracic eyespots, whereas larvae of the Old World Lauraceae­ feeding P. clythia and P. agestor groups differ greatly in appearance (Munroe, 1960). The precise phytogeographical and allelochemical (Whittaker and Feeny, 1971) role that the Lauraceae have played in the evolution of the Papilionidae is undoubtedly important, but not entirely certain. Forbes (1932, 1958) and Munroe (1948) suggested that the Graphiini were the most primitive of the Papilionidae and originally fed on Lauraceae with Papilio evolving directly from them in turn. Since the I • Lauraceae, along with the Annonaceae, Magnoliaceae and the Aristolo­ chiaceae, are generally considered to be among the most primitive of all flowering plants (Cronquist, 1968; Takhtajan, 1969), the suggestion was made that the Papilionidae originated in the late Jurassic (Forbes, 1932) and that it was generalized (polyphagous) species which were the ancestral types (Forbes, 1932, 1958). This date for the origin of the Papilionidae does not conflict with Smart and Hughes (1973) or Gressitt (1974). Because the phylogeny of the Graphiini is more clearly understood than most other groups of butterflies, Munroe ( 1948) felt that the zoogeographical distribution of the tribe would be of particular sig­ nificance and proposed the following: ( 1) Eurytides, which is repre­ sented by several species in the New World reportedly feeding on Lauraceae (D'almeida, 1966; Lima, 1968) and by a somewhat di­ vergent one in Australia, is the ancestral group of the more specialized Graphium. Other primitive groups of Graphiini appear to have relict distributions in Asia, which with the East Indies is their presumed place of origin. (2) The graphiines may have attained a global distribution during the Cretaceous or late Jurassic via the spread to all continents of the more primitive Eurytides. (3) During a later cooler period, perhaps the Laramide, when the higher graphiines such as Graphium either had not yet evolved, or at least not reached the New World along with more 12 JOURKAL OF THE LEPIDOPTERISTS' SOCIETY primitive forms, the Papilio glaucus and P. troilus groups (the genus being derived from the most primitive of the higher graphiines) were presumably able to spread into the more temperate North American continent. Fossil records supply evidence that plants very similar to the present-day Sassafras and Liriodendron had appeared in the middle latitudes by the early Cretaceous (Axelrod, 1966), further supporting Munroe's theory. Since that time however, the P. glaucus group has had a history which is purely North American (Munroe, 1963). If it is presumed that the P. glaucus and P. troilus groups are primitive, as Forbes (1932,1958) and Munroe (1948) suggest on the basis of an extra row of crochets on the pro legs, raised eyespots corresponding to the 3rd thoracic pair of spines in Graphium, the ancestral lauraceous foodplant, etc., then the South American P. homerus, P. scamander and P. zagreus complex in which the lauraceous foodplant is retained might be derived directly (Munroe, 1948). A major problem in understanding the phylogeny of the Papilionini is that there are a variety of superficial changes in pattern and structure. Furthermore there appears to have been an overwhelming switch of the "typical" Papilio of Forbes (1932) to the Rutaceae on a world wide basis. It was thought (Forbes, 1932, 1958) that the Rutaceae were secondary foods for the ancestral Papilionini, much as the Umbelliferae, Compositae, Rosaceae, and Piperaceae are today. Forbes' suggestion ( 1932) that the switch to Rutaceae might be related to the "similarity of flavor" has proven to be a fruitful starting point for several others who have investigated co-evolutionary relationships of the Papilionidae and their hostplants of which several secondary chemicals such as alka­ loids, essential oils and glycosides are shared (Dethier, 1941, 1970; Ehrlich and Raven, 1965; Feeny, 1975; Fraenkel, 1969; Scriber, 1972; and Slansky, 1972). Munroe and Ehrlich (1960) apparently resolved the alternative hy­ potheses presented in Munroe (1960) concerning the relationship of the red-tuberculate Aristolochia-feeding larva to the green, sometimes brown, sometimes spinose, Lauraceae-feeding or Rutaceae-feeding larva. The red-tuberculate larva must be primitive, meaning that the primitive Graphiini must have had red-tuberculate larvae and fed upon Aristolo­ chia, not on Lauraceae as was thought earlier (Forbes, 1932, 1958; Mun­ roe, 1948, 1960). Nevertheless the importance of the Lauraceae to the Graphiini and the Papilionini should not be overlooked. Although the polyphagous P. glaucus feeds successfully on Lauraceae, it would appear that for the glaucus-group as a whole (Brower, 1958), the preference for lauraceous foodplants is minimal and therefore has VOLUME 29, NUMBER 1 13 remained undetected. This is especially noticeable when the glaucus­ group is compared to the closely related troilus-group. Our initial ob­ servations are interesting perhaps in a qualitative sense because they emphasize the possibility of a co-evolutionary interaction between the two butterfly groups and one of the earliest of all angiosperm families. However more information is needed to make more meaningful quantita­ tive assessments of these particular relationships. ACKNOWLEDGMENTS Financial support was provided by N. S. F. Grant No. GB 33398 (P. P. Feeny) for the walk-in ovipositional cage, which was built and stocked with the assistance of R. Haskins and A. Miller. LITERATURE CITED AXELROD, D. 1. 1966. Origin of deciduous and evergreen habits in temperate forests. Evolution 20: 1-15. BnowEn, L. P. 1958. Larval foodplant specificity in butterflies of the Papilio glaucus group. Lepid. News 12: 103-114. CnoNQUlsT, A. J. 1968. The evolution and classification of flowering plants. Houghton Mifflin, Boston. 396 p. , .. D'ALMEIDA, R. E. 1966. Catalogo dos Papilionidae americanos. Sociedade Brazil­ eirade Entomologica, Sao Paulo, Brazil. 366 p. DETHIER, V. G. 1941. Chemical factors determining the choice of foodplants by Papilio larvae. Amer. Nat. 75: 61-73. 1970. Chemical interactions between plants and insects. Pages 83-102 in E. Sondheimer & J. B. Simeone, ed. Chemical ecology. Academic Press,