PROC. ENTOMOI.. SOC. WASH. 99(1). 1997. pp. 37-41 A NEW SPECIES OF DRYMUS FIEBER FROM MEXICO, WITH A KEY TO SPECIES AND A CHECKLIST OF WESTERN HEMISPHERE DRYMINI (HEMIPTERA: LYGAEIDAE) James A. Slater and Harry Brailovsky (JAS) Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, U.S.A; (HB) Departamento de Zoologia, Instituto de Biologia, UNAM, Apartado Postal No. 70-153, Mexico 04510, D. E, Mexico. — Abstract. The first Mexican species of Drymiis Eieber, is described as Drymus mex- icanus, n. sp., from the mountains of the state of Veracruz. A key to the Western Hemi- sphere species is included together with a list of the Western Hemisphere species of the tribe Drymini. A discussion of the distribution of the tribe is given and the affinities of the Nearctic fauna analyzed. Key Words: Drymus, Mexico, biogeography, distribution, checklist The zoogeography ofthe Rhyparochrom- breakup of West Gondwanaland. It also inae was reviewed in detail by Slater suggests that despite the abundance of the (1986). In that paper he noted the interest- Drymini in Australia they are relatively re- ing distribution of the members of the tribe cent elements in that fauna since there was Drymini and how closely the overall distri- apparently no movement of such a fauna bution paralleled that of the tribe Rhypar- across Antarctica (and because there are no ochromini. Both of these tribes are abun- native species in New Zealand). The most dant, diverse and speciose in the Palearctic, plausible scenario for the occurrence of Ethiopian-Oriental (= Paleotropical) and Drymini in the Western Hemisphere ap- Australian regions. However, both make up pears to be as a Holarctic element that was only a very small proportion ofthe Nearctic present during, or before, the onset of the rhyparochromine fauna and both are absent Pleistocene. If this is true, it means that from the the true Neotropical Region (in- two taxa have been able to reach generic cluding the West Indies). Of the Nearctic status during this period (both ofwhich are fauna most species belong to genera that are confined to areas ofCalifornia that escaped also found in the Palearctic. glaciation). The Drymini tend to be associated with The Mexican drymine fauna is found in woodland margins and to live in moderately montane areas and all species are members mesic habitats. The Rhyparochromini occur of genera also found in the United States for the most part in relatively dry savannah- and Canada as well as in the Palearctic. hke habitats. Drymus is the most unusual of these in that The absence from the Neotropics of the two previously known species are Drymini, despite their abundance in Afri- known from only a few localities in the ca, suggests a radiation subsequent to 90 western United States. million years b.p. or subsequent to the All measurements are in millimeters. 38 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON Fig. \. Drymus mexicanus. Dorsal view, head and pronotum. Drymus mexicanus^ Slater and the punctures on head and anterior pronotal Brailovsky, new species lobe relatively small. (Figs. 1, 2) Head acuminate, non-declivent; tylus at- taining distal one third offirst antennal seg- Robust, subelliptical. Head, anterior ment; vertex convex. Eyes set well away pronotal lobe, scutellum and antennae dark from anterior margin of pronotum. Length chocolate brown, almost black. Explanate head 0.84, width 1.00, interocular space pronotal margins, posterior pronotal lobe, 0.82. Pronotal calli confluent or nearly so, entire hemelytron, legs and labium dull red- mesally, elevated above surface ofposterior dish-brown. Fourth antennal segment with lobe. Lateral pronotal margins broadly ex- apical two-thirds white. Coarsely punctate planate (Fig. 1); posterior margin of pro- over entire surface except wing membrane. notum shallowly concave. Length prono- VOLUME 99, NUMBER 1 39 Fig. 2. Drymus mexicanus. Abdomen, lateral view. turn 1.20, width 2.00. Scutellum with a me- oHnco, 1.VIII.1977, 2100 m. In Universi- dian elevation distally, mesally concave on dad Nacional Autonoma de Mexico collec- basal half. Length scutellum 1.12, width tion. 1.20. Hemelytra with lateral margins broad- This is a very distinctive species at once ly convex. Clavus with four rows of punc- separable from the other Western Hemi- tures. Length claval commissure 0.60. Mid- sphere species by the white distal portion line distance apex clavus-apex corium 1.24. of the fourth antennal segment, the much Midline distance apex corium-apex mem- more strongly explanate lateral pronotal brane 0.64. Metathoracic scent gland auri- margins, and the shorter antennae. Actually cle curved posteriorly. Evaporative area this is not the only species of Drymus with only shghtly exceeding end of auricle, dis- a pale distal end to the fourth antennal seg- tally truncate, covering only mesal one- ment; several Palearctic species have a third to one-fourth of metapleuron. Fore fe- somewhat paler apex on segment four, al- mur only moderately incrassate, armed be- though none that we have examined have a low on distal one fourth with a short sharp white terminal end to the antennae. spine with three minute spines distad. La- bium extending to metacoxae, first segment Key to Western Hemisphere not attaining base of head. Length labial Species of Drymus segments I 0.62, 11 0.70, III 0.54, IV 0.44 (approx.). Length antennal segments I 0.50, 1. Distal half of fourth antennal segment white, stronglycontrastingwithdarkcolorationofba- II 0.80, III 0.62, IV 0.68. Total body length sal halfofantennae; explanate margins ofpro- 5.65. notum broad, subequal to width of second an- All abdominal spiracles located below tennal segment; second antennal segment sub- sternal shelf. Posterior pair of trichobothria equal in length to length of head on sternum four located dorsoventrally, the mexicanus n. sp. - Fourth antennal segment unicolorous dark ventral trichobothrium reduced and obso- brown to black; explanate lateral pronotal mar- lete (Fig. 2). gins relatively narrow, much narrower than Holotype 9 MEXICO: Veracruz: Na- width of second antennal segment; second an- 40 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON tennal segmentconsiderably longerthan length melanotus Walley 1929. British Columbia; of head 2 Idaho. 2. Large (6.5-7 mm); verydarkalmostblack; an- mimbresianus Brailovsky and Cervantes teriorand posteriorpronotal lobes nearlyeven- ly punctate; expanded lateral margins of pro- 1989. Mexico. notum concolorous with doraal surface ofpro- obscurus Van Duzee 1906. California; Ida- notum crassus Van Duzee ho; British Columbia. - Smaller (rarely over 5 mm); dull brown; ante- opacus Van Duzee 1921. California. rior pronotal lobe more finely punctate than semicinctus Van Duzee 1921. California; posterior lobe; expanded lateral margins of pronotum usually slightly palerthan surfaceof Idaho. pronotum units (Say) setosus Blatchley 1926. Eastern U.S.A. squalidus Brailovsky and Barrera 1981. Checklist of Western Hemisphere Mexico. Drymini Gastrodes Westwood See Slater 1964 and Slater and O'Don- arizonensis Usinger 1938. Arizona. nell 1995 for complete references. conicolus Usinger 1933. California. Drymiis Fieber intermedius Usinger 1938. British Colum- bia. crassus Van Duzee 1910. New England pacificus (Provancher) 1886. Nebraska and south to Florida, west to Texas and South Colorado, west to Calfornia and British Dakota. Columbia. mexicanus, n. sp. Mexico. walleyi Usinger 1938. Ontario, British Co- unus (Say) 1831. Eastern Canada, south to lumbia. North Carolina, west to Colorado. Scolopostethus Fieber Eremocoris Fieber otianticus Horvath 1893. Northern U.S.A. aniaudi Brailovsky 1982. Mexico. and southern Canada; Newfoundland to borealis (Dallas) 1852. Western U.S.A. British Columbia south to New Jersey canadensis Walley 1929. British Columbia; and New Mexico. Idaho. diffidens Horvath 1893. Northern U.S.A. chalmaensis Brailovsky and Barrera 1981. and southern Canada: Nova Scotia to Mexico. British Columbia south to New Jersey. cupressicola Ashlock 1979. California. pacificus Barber 1918. California, Idaho, depressus Barber 1928. New England south British Columbia. to Florida and Louisiana coastal areas. thomsoni Reuter 1874. Almost throughout dimidiatus Van Duzee 1921. Colorado. Holarctic. extremus Brailovsky and Cervantes 1989. tropicus (Distant) 1882. California to Gua- Mexico. temala. ferus (Say) 1832. Widespread over much of Thylochromus Barber U.S.A. and southern Canada. garciai Brailovsky and Barrera 1981. Mex- nitidulus Barber 1928. California. ico. Togodolentus Barber guerrerensis Brailovsky and Barrera 1981. Mexico. wrighti (Van Duzee) 1914. California. inquilinus Van Duzee 1914. California. Acknowledgments legionarius Brailovsky and Barrera 1981. Mexico. We express our appreciation to Mr. Er- lopezformenti Brailovsky and Barrera 1981. nesto Barrera (UNAM) Mexico for prepa- Mexico. ration of the illustrations and to Dr. Jane VOLUME 99, NUMBER 1 41 O'Donnell, University of Connecticut, for . 1986. A synopsisoftheZoogeographyofthe assistance with the manuscript. Rhyparochrominae (Heteropteraa: Lygaeidae). Journal of the New York Entomological Society Literature Cited 94: 262-280. Slater, J. A. 1964. A Catalogue of the Lygaeidae of Slater, J. A. and J. E. O'Donnell. 1995. A Catalogue the World. 2 Volumes. University ofConnecticut. ofthe Lygaeidae ofthe World (1960-1994). New Storrs. 1688 pp. York Entomological Society, 410 pp.