. Revista Chilena de Entomología. Vol. 6, diciembre 1968 47 STUDIES IN NEOTROPICAL ACROCERIDAE, PART I. A REVISIÓN OF ARRHYNCHUS PHILIPPI AND A KEY TO THE GENERA OF THE OCNAEA BRANCH OF THE PANOPINAE (DÍPTERA) 1 EVERT I. SCTILINCER Department o£ Entomólogo' University of California Riverside, California ABSTRACT The Chilean genus Arrhynchus Philippi is reinstated (= Ocnaea of authors) and revised. The type species, A. vittatus Philippi, is redescribed, while new combinations propo-sed are A. stuardoi (Sabrosky) and A. meridionalis (Sabrosky) . The new species, A. penai Schlinger and A. macula- tus Schlinger are described and notes are given on the rearing of the latter species from a theraphosid spider. INTRODUCTION ACKNOWLEDGMENTS A study of this rare group of Díptera could not have ráre Arrhynchus was descri- The rather genus been, completed without the kind assistance of many in- bed by Philippi (1871) and he included in terested persons and institutions. I express roy sincere gratitude to cióse friend, Luis E. Peña, now with the it only its monotype, A. vittatus Phil., from my Universidad de Chile, who greatly aided my field studies Chile. When Edwards (1930) discussed the in Chile and loaned me important material, and to acrocerids o£ Chile he suggested (without one of my gradúate students, Michael E. Irwin, who seeing any specimens) that Arrhynchus was helped to gather much important field data on Chilean acrocerids during 1966-67. Miss Maria Etcheverry, probably a synonym of Ocnaea Erichson. It To Centro Investigaciones Entomológicas, Universidad de wasn't until I had the opportunity to see the Chile, Mr. H. Toro, Universidad Católica, Valparaíso type specimen of A. vittatus and other spe- and Guillermo Kuschel, now in New Zealand, I am in- cimens of this genus that I became certain debted for the loan of specimens, and specially to the latter person who was responsible for the loan of the Arrhynchus was a valid genus but one closely Philippi type specimens from the National Museum related to Ocnaea. Philippi (1871) apparently ccllection in Santiago, Chile, which is now under the ovas unaware of the genus Ocnaea, for he re- curation of Vicente Pérez. lated his new genus only to Panops (nec. La- My eight-month expedition in Chile was sponsored marek, but rather to Chilean species of Lasia both by the John Simón Guggenheim Foundation and by the Convenio Program of the University of Califor- Wiedemann as he knew them) nia and Universidad de Chile, and their generous assis- Arrhynchus now includes five species and tance is greatly appreciated. Excellent laboratory faci- is apparently autochthonous to Chile, while lities at the Estación Experimental Agronómica at La Rinconada, Chile, were made available to me to study Ocnaea oceurs from southern United States acrocerids and their spider hosts, and I wish to acknow- south to Brazil, but does not oceur in Chile. ledge my colleagues Dr. Roberto González, Dr. Luciano This is the fifteenth in a series of articles Campos, Mr. Raúl Cortés, Mr. Nelson Hichins and others on the Entomology staff for their friendly help dealing with reviews or revisions towards a and interest while I was studying in Chile. monograph of the Acroceridae. Two papéis The abbreviations listed below are used in the text citing are most of the references in this series to determine the present location of the speciment used those of Schlinger (1961 and 1968) . This is in this study: also the first in a planned series dealing with (lp) — Señor Luis. E. Peña collection, Santiago, Chile, systematics, biologies, distributions and taxo- (cuv) — Universidad Católica de Valparaíso, Chile. nomic notes on Neotropical acrocerid flies. (cas) — California Academy of Sciences, San Francisco, California, usa. 'Part of this study was undertaken while the author (amnh) — American Museum of Natural History, New was a Guggenheim Fellow in Chile, 1966-67. York, New York, usa. Rev. Chil. Ent. 6, 1968 (usnm) — United States National Museum, Wash- Arrynchus Philippi ington, DC., USA. (cíe) — Centro Investigaciones Entomológicas, Univer- Arrhynchus Philippi, 1871: 291-292; Reed, sidad de Chile, Santiago, Chile. 1888: Hunter, 1901: Kertes'z, (eea) — Estación Experimental Agronómica, Universi- 288; 152; dad de Chile, Maipú, Chile. 1909: 11. — I. Schlinger collection, University of Ca- (eis) Evert Ocnaea oí authors, nec. Erichson; Edwards, lifornia, Riverside, California, usa. 1930: 188, Stuardo, 1946: 102, Sabrosky, (cnhm) — Museo Nacional de Historia Natural de Chi- le, Santiago, Chile. 1946: 190. Type species: Arrhynchus vittatus Philippi, SYSTEMATICS by monotypy. Key to the Neotropical genera of the Ocnaea branch of the Panopinae (Acroceridae) Diagnosis: Médium to large flies (8 to 16 mm. long) , black or bluish-black with yellow 1. Eyes pilóse 2 or orange markings. Eyes pilóse, antennae Eyes bare (Central America) . Appelleia Bellardi much longer than head height (males) , or as 2. Vein iíj present, usually complete but always with at least a basal or apical stub; wing membrane bare, long as or up to ]/¿ as long as head height or macrotrichiae and/or mi- with some, with many (females) ; ocelli present (2 or 3) median oce- crotrichiae on costal, subcostal, marginal and occasio- llus may be present and distinct or apparently nally on submarginal posterior and other cells . 3 absent; eyes narrowly separated between an- of nu- Vein R í absent; much wing membrane with distinctly merous macrotrichiae on costal, subcostal, marginal tennal triangle and post clypeus, but and/or submarginal, posterior, discal, basal, cubital separated from frons to ocellar tubercle; an- and anal cells (Brazil and Bolivia) tennae placed near but distinctly below vér- Exetasis Walker2 tex, separated from ocellar triangle and an- 3. Eyes holoptic below antennae 4 terior edge of frons by distance equal to, or Eyes at least partly and usually considerably sepa- segment I rated below antennae; antennae placed at, below greater than, length of antennal or slightly above mideye height; antennae placed (see Figs. 2, 4, 8, 12, 14) ; clypeus present but underneath or in front of large frontal tubercle; small, prementum hardly visible: wing vena- humeral cross vein absent. (Brazil, Ecuador, Gua- tion strong, vein R branched; trichiation temala) Pialea Erichson3 4+5 of wing membrane limited to costal and sub- 4. Antennae placed high on head just in front of ocellar tubercle, or about % upon head 5 costal cells and quite faint: legs strongs, pul- Antennae placed at or below mideye height; basal villi narrow (especially empodia) , shorter cervical sclerite hardly visible (Chile) than claw length. new genus* Distribution: The five known species are 5. Antennae placed just in front of ocellar tubercle; eyes widely separated between antennae and ocellar recorded only from Chile, and this is good tubercle: ocellar tubercle well-raised prominent evidence to support the idea that Arrhynchus lateral ocellus (California-North Carolina, south to is endemic and/or autochthonous to that Brazil Ocnaea Erichson región. Antennae somewhat lower on head with eyes more narrowly separated between antennae and ocellar Discussion: Arrhynchus is similar to Ocnaea, barely raised, tubercle; ocellar tubercle flattened or Exetasis and Pialea, and is somewhat inter- triangular with distinct or indistinct median ocellus, medíate between Ocnaea and Pialea. It is most but lateral ocellus is prominent (Chile) Arrhynchus Philippi similar to Ocnaea with which genus it had been synonymized by Stuardo (1946) without 2The genus Exetasis "Walker (1852) has been consi- stating why. The main differences between dered synonym of Ocnaea Erichson by most authors, a Arrhynchus and Ocnaea are in the placement but the significant characters given here in the key clear- of the antennae, the development of the ly indícate it should have sepárate taxonomic status. 3The genus Stenopialea Speiser from South África is ocellar tubercle and vertical áreas, wing tri- related to Pialea, but its species have a distinct humeral chiation, head shape and size of occiput. crossvein. To this monotypic genus can now be added 'This new genus from Chile is being described by the author in another paper n.ow in preparation. four additional species from Chile. These are: . Schlinger: Neotropical Acroceridae, part I. Coll. Ocnaea stuardoi Sabrosky, O. meridionális (cas) ; 1 9 , same xi-20-46, E. P. Reed, (eis) 1 Sabrosky, A. penai Schlinger, n. sp. and A. (cas) ; 1 9 same, xi-29-54, L. Peña ; maculatus Schlinger, n. sp. 9 , same, x-1952 (amnh) ; 2 9 , same, 1949, E. P. Reed, coll. (cas) ; 1 9 same, xn-1950, (cas) 1 , KEY TO THE SPECIES OF ARRHYNCHUS L. Peña ; 9 El Manzano, Jan. 1959, PH1LIPPI5 (eis) 1 Quilpué, 1-1962, G. Monsalve, ; 9 , J. Verguez (cuv) ; 2 á, Quebrada de la Plata, 1. Males (antenna longer than head height) . 2 Stgo. Prov., malaise trap, 1-12-67, M. E. Irwin Females (antenna as long or shorter than head (eis, eea) ; 1 , Viña del Mar, Valparaíso height) 3 $ Prov., x-1961, E. González (cuv) 2. Tergum metallic bluish-black with contiguous yellow, lateral spots on at least segments ii-m; Discussion: The females of this species are raesonotal pile brownish or greyish-white .... dark metallic bluish-black, but the males are vittatus Philippi somewhat less shiny and black, or sometimes Tergum more dull black or black with small, dor- with dull, orange, lateral, tergal spots on ter- sally-interrupted orange lateral spots sometimes on segments H-v; mesonotal pile black gites 11-v or on fewer segments and sometimes stuardoi (Sabrosky) the intersegmental membranes between ster- 3. Mesonotum shiny bluish-black 4 nites and tergites are also orange. This orange penai Schlinger, n. sp. Mesonotum orange .... color of the tergum is somewhat similar to 4. Tergum entirely shiny bluish-black 5 darker specimens of A. vittatus, except the Tergum with large, lateral yellow área or spots on spots in stuardoi are not contiguous in dorsal segments ii-iii or ii-iv 6 view.