PROCEEDINGS ENTOMOLOGICAL SOCIETY of WASHINGTON
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PROCEEDINGS of the ENTOMOLOGICAL SOCIETY of WASHINGTON OF MANY SIMILAR SPECIES IN THE NEOTROPICAL GENUS PORPHYROGENES (LEPIDOPTERA: HESPERIIDAE), A NEW ONE, REPEATEDLY REARED IN COSTA RICA, IS RELATIVELY DISTINCT JOHN M. BURNS,DANIEL H. JANZEN, AND WINNIE HALLWACHS PROC. ENTOMOL. SOC. WASH. 112(1), 2010, pp. 32–42 OF MANY SIMILAR SPECIES IN THE NEOTROPICAL GENUS PORPHYROGENES (LEPIDOPTERA: HESPERIIDAE), A NEW ONE, REPEATEDLY REARED IN COSTA RICA, IS RELATIVELY DISTINCT JOHN M. BURNS,DANIEL H. JANZEN, AND WINNIE HALLWACHS (JMB) Department of Entomology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 127, room E-515, Washington, DC 20013-7012 USA (e-mail: [email protected]); (DHJ, WH) Department of Biology, University of Pennsylvania, Philadelphia, PA 19104 USA (e-mail: DHJ djanzen@ sas.upenn.edu, WH [email protected]) Abstract.—Associating sexes in many species of the Neotropical hesperiid genus Porphyrogenes has been difficult, erroneous, or impossible, owing to their sexual dimorphism. Despite the extreme sexual dimorphism of Porphyrogenes peterwegei Burns, new species, full description of this rainforest skipper from Area de Conservacio´n Guanacaste (ACG), northwestern Costa Rica, is no problem. The available sample amounts to nearly 100 reared adults, almost evenly divided between the sexes. Of these, 67 have been DNA barcoded and found to vary minimally in their COI haplotypes, with one haplotype predominating. Caterpillars and pupae consistently go through a distinctive set of developmental changes in their color patterns. Foodplant choice is conservative: of 227 immatures found in the wild, 94% were eating woody vines of the genus Machaerium, especially M. seemannii (Fabaceae), whereas 6% were feeding on the quite unrelated species Dichapetalum morenoi (Dichapetalaceae)—a peculiar pattern of larval foodplant selection seen in another skipper and two butterfly species in ACG. Caterpillars of P. peterwegei are occasionally attacked by a host-specific parasitoid (an undescribed tachinid of the genus Siphosturmia), which has not otherwise been encountered in 20,642 tachinid attacks on the caterpillars of .3,000 species of Lepidoptera in ACG. Morphologically, P. peterwegei differs significantly from its many congeners in both facies and genitalia. Key Words: Genitalia (male and female), sexual dimorphism, caterpillars, pupae, foodplants (Machaerium), DNA barcodes, tachinid parasitoid DOI: 10.4289.0013-8797.112.1.32 Speciation is kind to taxonomists ally valuable to taxonomists when, when, within a bevy of similar related among similar species, sexual dimor- species, an undescribed one differs phism is so great that associating the visibly from the rest. Multiple rearings sexes has often been incorrect or and DNA barcodes become exception- impossible. A recent detailed treatment of Porphyrogenes (Austin and Mielke * Accepted by Robert R. Kula 2008) recognizes 26 species (including VOLUME 112, NUMBER 1 33 the one named here), as well as three 2009) and have been deposited in the previously named but unassociated National Museum of Natural History females and five unnamed unassociated (USNM), Smithsonian Institution, females (which may or may not repre- Washington, District of Columbia, sent additional species). Owing, at least USA (see Type material). (In addition, in part, to their late-afternoon, crepus- seven reared adults preserved in EtOH cular, and perhaps nocturnal behavior, have been deposited in the Monell Cryo adults of these sizeable Neotropical Collection for Molecular and Microbial skippers have always been rare in Research at the American Museum of collections. Indeed, six of the nine Natural History, New York, New York, new species of Porphyrogenes in Austin USA; three have been deposited in the and Mielke (2008) are described from a Lepidoptera Tree of Life collection at single specimen, which is always male. the University of Maryland, College Porphyrogenes is known from most Park, USA.) The massive rearing pro- of Central and South America. Specific gram in Costa Rica is described in records extend from Belize (J. A. Shuey Burns and Janzen (2001), Janzen and pers. comm.), Honduras, Nicaragua, Hallwachs (2009), and Janzen et al. Costa Rica, and Panama, to Colombia, (2009). Four wild-caught adults of Ecuador, Peru, Bolivia, Paraguay, and Porphyrogenes have been borrowed northern Argentina, and all mainland from the Instituto Nacional de Biodi- countries to the east, plus Trinidad versidad (INBio), Santo Domingo de (Austin and Mielke 2008). About Heredia, Costa Rica. three-quarters of the species occur in In the course of rearing enormous South America and one-third in Central numbers of Lepidoptera and their par- America(thesefiguresincludetwo asitoids in ACG, new species have been species attributed to both regions and discovered at a rate far greater than that exclude one species from no one knows atwhichtheyhavebeenformally where). Although it is not surprising named and described. Temporary des- that 16 of the 26 species have been ignations are needed for referring to found in Brazil (Austin and Mielke undescribed species. When such species 2008), there are, at the very least, 12 are thought to be very closely related to species (two undescribed) in just the one that is already named, that name is limited (and ecologically less diverse) used, but it is followed by a code with area of French Guiana (B. Hermier in letters that denote the worker who litt.). What with the similarity of many detects two or more species instead of species, their excessive sexual dimor- just one and with numbers (01, 02, 03, phism, and a lack of material, the etc.) that arbitrarily distinguish these geographic distribution of many de- species—for example, Genus species scribed species is still nebulous, and XYZ01. When an undescribed species the number of undescribed species is can be placed to genus but no further, conjectural. its designation is simply Genus XYZ01. Forewing length of adults was mea- MATERIALS AND METHODS sured from base of costa to apex with a Adult specimens used in this study vernier caliper calibrated to tenths of a have been reared from caterpillars millimeter. After each measurement collected during an ongoing bioinven- was recorded, the distance between tory of Lepidoptera in Area de Con- caliper prongs was significantly reduced servacio´n Guanacaste (ACG), north- before the next specimen was mea- western Costa Rica (Janzen et al. sured. The measuring sequence was a 34 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON Figs. 1–4. Reared paratype male, voucher code 04-SRNP-4400 (above) and holotype female (below) of Porphyrogenes peterwegei from ACG, Costa Rica, in dorsal (left) and ventral (right) view; pins and pinholes artificially removed; scale bar ¼ 1cm. random mix of males and females, and (except for two species) are spotless. all but two specimens were measured The female of P. peterwegei is unique in on the same day. Nudum segments of having only one spot—an outsized one the antennal club were counted with the in the center of the forewing (in cell aid of a stereomicroscope at a magni- CuA1-CuA2) (Figs. 3–4). Although fication of 403. After treatment with females of a few other species have a 10% KOH, genitalia were dissected similar large central spot, they also have with the aid of a stereomicroscope and a small distal spot (in cell M3-CuA1) thereafter were kept free in glycerin. (see figures in Austin and Mielke 2008). For details on the handling, comparison, ThemaleofP. peterwegei shares and storage of unmounted genitalia, see whitish wing fringes (Figs. 1–2) with Burns (1997). For information on meth- just one other species, P. stupa Evans, ods used in DNA barcoding, see which is known from a single dataless Hajibabaei et al. (2006). male whose ground color is virtually black with a purplish sheen, instead of RESULTS Porphyrogenes peterwegei Burns, dark brown as in P. peterwegei, and new species whose hind wing is broad, rounded, and lacking a tornal lobe, while that of P. Diagnosis.—Females of Porphyro- peterwegei is narrow with a prominent genes always have one or more fore- tornal lobe. wing spots (joined, in some species, to Description.—Size: Females average form a transverse band), whereas males larger than males. Forewing length in VOLUME 112, NUMBER 1 35 mm: Male: Mean ¼ 22.93, SD ¼ 0.982, (though variably) paler than ground n ¼ 45, Range 21.0–24.7. Female: Mean color, especially above tornal lobe. ¼ 25.77, SD ¼ 1.378, n ¼ 51, Range Hind wing postmedian band of darker 23.0–28.5. NB: Owing to the unnatural spots more evident than in male, and inferior conditions of rearing, especially ventrally. More or less con- reared adults average smaller than wild spicuous pale gray, submarginal to ones; the degree of dwarfing varies, marginal strip (interrupted by darker especially with respect to the stage of veins) distal to ventral hind wing the caterpillar when found. The three spotband and contrasting with it. Sim- ilar marginal strip of still paler gray on males and four females obtained from ventral forewing. All of ventral fore- wild-caught pupae of this species are wing space between vein 2A and inner near or at the upper end of the size margin extra pale. Legs dull orange. range, given above, for each sex. Secondary sex characters: Male: Number of segments in nudum of Forewing with costal fold. Forewing antennal club: The sexes do not differ. vein 2A bowed anteriad and, along Mean ¼ 29.96, SD ¼ 1.259, n ¼ 76, highest reaches of its arc, swollen and Range 27–34. The number of nudum ventrally devoid of scales; vein 2A, segments is not correlated with length from swollen stretch to base of wing, of the forewing. bisecting ventral speculum comprising Wing shape (Figs. 1–4): Sexual variously modified scales. On dorsal dimorphism pronounced. Wings of hind wing, two conspicuous, adjacent, male narrow and apically pointed; those distally light-brown and proximally tan of female broad and apically rounded.