Strymon

Abstract: All Lycaenidae larvae that eat Bromeliaceae belong to the Strymon ziba and S. serapio species groups, but confusion with taxonomy has resulted in widespread misidentification of the butterflies in both the ecological and agricultural literature. Published food plant records are assessed, and new rearing records are presented. The species that have been recorded eating Bromeliaceae are Strymon ziba (Hewitson), S. megarus (Godart), S. lucena (Hewitson), S. oreala (Hewitson), S. serapio (Godman & Salvin), S. azuba (Hewitson), and S. gabatha (Hewitson). The first four are recorded from pineapple, with the sympatric S. megarus and S. ziba sometimes being especially destructive in commercial fields. Most published records lump these two species and misidentify them under the names Thecla basilides, Thecla basalides, or Tmolus echion. Strymon ziba has also been reared from other monocotyledon plant families, such as Heliconiaceae and Haemodoraceae. In most cases, caterpillars eat flowers and fruits, but larvae o...

Abstract: North American Strymon Hiibner was revised about 40 years ago, and the significantly larger Neotropical Strymon is now incorporated into this classification. Strymon is characterized by anteriorly directed teeth on the posterior dorsal surface of the valvae. These teeth were first noted by Clench and appear to be modifications of the sockets of setae that normally occur on eumaeine valvae. This characterization is most consistent with past usage and appears to represent the best evidence for monophyly. As characterized, Strymon contains 48 described species. Variation in morphology of the male genitalia, female genitalia, wings, and head is documented, and male behaviors and larval foodplant records are summarized. We tentatively divide Strymon into species groups, one of which is unusual in its use of Bromeliaceae as its sole larval foodplant. One recently described genus, Heoda Johnson, L. Miller & Herrera 1992, and one recently resurrected genus, Eiseliana Toledo 1978, are made junior synonyms of Strymon Hiibner 1818. Six names recently described in Strymon are transferred to other genera: Strymon angulus Le Crom & Johnson, 1997 to Thereus Hiibner; Strymon daplissus Johnson & Salazar, 1993 to Ministrymon Clench 1961; Strymon carmencitae Le Crom & Johnson, 1997 and Strymon cryptogramus Johnson, Eisele & MacPherson, 1992 to Nicolaea Johnson; Strymon nivnix Johnson, Eisele & MacPherson, 1990 to Calycopis Scudder; and Strymon additionalis Le Crom & Johnson, 1997 to Thecla F. The hindwings of Strymon nivnix are designated a leetotype, and Strymon anthracaetus Salazar, Velez, & Johnson, 1997 is regarded as a nomen dubium. Additional key words: Bromeliaceae, foodplants, territoriality, Heoda, Eiseliana. Strymon Hiibner is possibly the best-known New World hairstreak genus (Lycaenidae: Theclinae: Eumaeini). R occurs from Canada to the temperate parts of Chile and Argentina. Some Strymon are common and well-known, such as S. melinus (Gray Hairstreak), and some are pests on commercial pineapple, such as S. ziha (Hewitson), S. megarus (Godart), and relatives (Harris 1927, Carter 1934, Fonseca 1934, Zikan 1956, Guagliumi 1965, 1967, D'Araujo e Silva et al. 1967-1968, Beutelspacher 1972, Otero & Marigo 1990). The name Strymon has been widely used in North America; the first extensive list of North American Strymon species (Barnes & McDunnough 1917) contained about 40 taxa and was followed by similar listings (Barnes & Benjamin 1926, McDunnough 1938, Klots 1951, Dos Passos 1964). Although Ziegler (1960) and Clench (1961) rather drastically changed the characterization of Strymon, 14 of the 48 described Strymon species currently recognized (Appendix 1) are recorded from North America (Opler & Malikul 1992, Opler & Wright 1999). "Modern" taxonomic usage of Strymon began when the genus was distinguished primarily by genitalic structures (Ziegler 1960, Clench 1961). With increased knowledge of the Neotropical eumaeine fauna, however, it became clear that these characters, as originally proposed, do not delimit Strymon. For example, S. yojoa (Reakirt) has small anteriorly directed teeth on the dorsal valva tips•a structure mentioned in Clench's generic diagnosis•but lacks a tightly convoluted spiral of the ductus bursae (Fig. 20)•a structure noted in Ziegler's generic characterization. Alternately, S. serapio (G. & S.) has the tightly-convoluted spiral (Fig. 25), but also has a double cornutus, not the single acuminate one described by Clench (1961) (Fig. 16). To complicate matters, the subsequently described genera Eiseliana Toledo and Heoda Johnson, Miller, & Herrera possess some genitalic structures that Ziegler and Clench used to characterize Strymon. Finally, six species described in Strymon since 1990 possess none of these characters. The purposes of this paper are to characterize Strymon, so that it will be clear which species belong to Strymon, and to provide an overview of the comparative morphology and ecology of the genus. Specifically, this paper (1) outlines the nomenclatural history of Strymon, (2) suggests that the best structure for distinguishing Strymon is the unique morphology of the male genitalia valvae, which was first noted by Clench, (3) describes and illustrates morphological variation within the genus, (4) summarizes information on male behavior, larval foodplant specificity, and habitat, (5) preliminarily partitions Strymon species in nine species groups, and (6) transfers six names from Strymon to other genera. This work is intended to set the stage for a species revision, including the description of about five new species, mostly from the dry mountains of Peru and southern Ecuador. JOURNAL OF THE LEPIDOPTERISTS' SOCIETY MATERIALS AND METHODS The results in the this paper were based upon a comparison of adult morphology using the 6,000+ specimens of Strymon in the National Museum of Natural History (Smithsonian Institution, Washington, DC, USA), of which 3,972 are Neotropical, plus many specimens borrowed from other museums. This comparison employed standard entomological techniques (Robbins 1991), including the examination of the male and female genitalia (449 dissections) of all species currently recognized in Strymon (Appendix 1), except that we relied on genitalic figures of two species. For those names that we could not identify from their original descriptions, we examined their types or pictures of the types. For only one species, Strymon anthracaetus Salazar, Velez, & Johnson, could we not identify the name or find its type (explained below). In preparing a checklist of all Neotropical hairstreaks (Robbins in press), RKR examined the adult morphology of virtually all Neotropical species, although not in the same detail as with Strymon. All genitalic terms follow those in Klots (1970). All specific author names for Strymon are listed in Appendix 1 and thus are omitted from the following text. Because relationships within the Eumaeini are still poorly known, such as the genera that are most closely related to Strymon, we characterize Strymon by a complex and conspicuous trait that is unique within the Eumaeini and that is phylogenetically consistent with other traits that are unique within the Eumaeini. We tentatively divide Strymon into species group on the basis of many characters, but evidence for their monophyly awaits formal phylogenetic analysis. NOMENCLATURAL HISTORY Hiibner (1818) described Strymon and included two species, S. melinus and Hesperia acaciae Fabricius. (Hesperia currently belongs to the Hesperiidae.) A subsequent list of 13 Strymon species (Hiibner 1819) caused considerable confusion in the eventual selection of a type species. Scudder (1872) selected Hesperia titus F. from the 1819 list as the type (the dates of Hiibner s books were uncertain at the time), but Riley (1922) invalidated this selection and replaced it with Strymon melinus. Finally, the International Commission on Zoological Nomenclature (1959) placed Strymon on the Official List as Name No. 1332 with Strymon melinus as type. Hemming (1967) gives a more complete nomenclatural history.