SYSTEMATICS A New Species of Eupithecia (Lepidoptera: Geometridae) from the Juan Ferna ´ ndez Islands LUIS E. PARRA 1 AND HE ´ CTOR IBARRA-VIDAL 2 Ann. Entomol. Soc. Am. 95(1): 9Ð15 (2002) ABSTRACT Eupithecia robinsoni sp.nov.isdescribedfromtheJuanFerna ´ ndez islands. This species is associated with Gunnera peltata Phil. The egg, larva, pupa, adult, and genitalia are described and illustrated. Preliminary results of the natural history of this species are given and compared with biology of E. horismoides Rindge, 1987. KEY WORDS Larentiinae, Eupithicini, Eupithecia robinsoni sp. nov., Eupithecia horismoides, Gun- neraceae, Chile THE JUAN FERNA ´ NDEZ Islands lie isolated in the PaciÞc Ocean at 33° S latitude some 600 km west of mainland Chile. The archipelago consists of three major islands, Masatierra (Robinson Crusoe Island), Masafuera (AlejandroSelkirkIsland),andSantaClarajustoffthe coastofMasatierra.Thesethreeislandsareofvolcanic origin, and they are 4 million (Masatierra) and 1Ð2 million (Masafuera) years old (Stuessy et al. 1984). The islands have long been known for their unusual and endemic ßora (70% of the 147 species of angio- sperms) (Hoffmann and Marticorena 1987) and en- demic arthropod fauna (65% of 764 species) (Pen ˜ a 1987). Eupithecia Curtis is probably the most widely dis- tributed genus of the subfamily Larentiinae, being well represented throughout the world except in the Polar Regions. It is difÞcult to distinguish one species from another due to their small size and similar wing patterns. Nevertheless, the genital organs of both sexes usually provide speciÞc characters by which species may be distinguished. Various efforts have been made to separate the species into different gen- era (Vojnits 1985). However, the characters used rep- resent slight variations that, according to Rindge (1987),donotjustifytaxonomicchangeatthegeneric level. Fifty species of Eupithecia are recognized in conti- nental and oceanic Chile (Rindge 1987, 1991). Bio- logical information is available for only one species E. horismoides Rindge, which has a life cycle associated with Gunnera tinctoria (Mol.) Mirb. (Gunneraceae) in continental Chile (Ibarra-Vidal and Parra 1993). The discovery of an undescribed species of Eupithecia associated with Gunneraceae on Robinson Crusoe Is- land, adding to the recognized endemic biota of the Juan Ferna ´ ndez Islands (Pen ˜ a 1987), motivated the current study. Materials and Methods The material used in this study comes from collec- tions made in the Juan Ferna ´ ndez Islands, January 1996. Numerous samples of G. peltata Phil. and G. bracteata Steud. from Robinson Crusoe Island and samples of G. masafuerae Skottsb. from Alejandro Sel- kirk Island were studied. Larvae and pupae from the stalks of G. peltata were collected and studied. All material was compared with published information and with other specimens collected from the Juan Ferna ´ ndez Islands during the same excursion. The specimens used in this study were deposited in the MuseodeZoologõ ´a,UniversidaddeConcepcio ´ n,Con- cepcio ´ n, Chile (MZUC), Museo Nacional de Historia Natural, Santiago, Chile (MNHN) and The Natural History Museum, London, UK (BMNH). Eupithecia robinsoni sp. nov. Types. Holotype , 10Ð25 January 1996 (MZUC); Allotype ,18January1996(MZUC);Paratypes: ,18 January 1996 (MNHN); , 20 January 1996 (BMNH); , 19 January 1996 (MZUC); , 13 January 1996 (MZUC),allfromPlazoletaElYunque,RobinsonCru- soe Island, in G. peltata, H. Ibarra-Vidal col. Immature Stages. 14 eggs, Plazoleta El Yunque, RobinsonCrusoeIsland,in G. peltata, 13January1996, H. Ibarra-Vidal col. (MZUC). Five larvae (MZUC), threelarvae(MNHN),twolarvae(BMNH),Plazoleta El Yunque, Robinson Crusoe Island, in G. peltata, 10Ð25 January 1996, col H. Ibarra-Vidal. Male (Fig. 1a). Head and palp dark brown. Antenna with a pair of basal projections; lamellate, rounded, ßat, with pair wider than segment, distal pair of pro- jections similar but smaller, and both pairs bearing long setae. Middle ßagellomers of the antenna mostly 1 Departamento de Zoologõ ´a, Facultad de Ciencias Naturales y Oceanogra ´ Þcas, Universidad de Concepcio ´ n, Casilla 160-C, Concep- cio ´ n, Chile (e-mail: luparra@udec.cl). 2 Exp Ediciones al Conocimiento, Casilla 2916, Concepcio ´ n, Chile (e-mail: hibarra@latinmail.com). 0013-8746/02/0009Ð0015$02.00/0  2002 Entomological Society of America Downloaded from https://academic.oup.com/aesa/article/95/1/9/2759129 by guest on 18 May 2023