Erlandia mexicana, Noguera & Chemsak, 2001

Noguera, Felipe A. & Chemsak, John A., 2001, A New Species Of Erlandia Aurivillius From México (Coleoptera: Cerambycidae: Cerambycinae), The Coleopterists Bulletin 55 (3), pp. 369-373 : 369-372

Erlandia mexicana new species

Fig. 1 ,

Description. Female. Size small, elongate, dorsoventrally compressed; integument reddish brown, shining, apices of mandibles, anterior margin of front, genae, antennal insertions, basal and apical margins of the pronotum, margins of pro­ and mesocoxal cavities, bases and apices of femora and areas of abdominal segments black; body clothed with shining pale yellow setae. Head broader than long; mandibles robust, almost 1/3 as long as head, strongly curved at apices, internal margins without teeth; clypeus arcuate, very narrow at middle, with a fringe of reddish setae which extends to the middle of the mandibles; front short, broad, base arcuate, with a shallow, median, longitudinal depression which extends onto the vertex, each side with an impunctate area; vertex convex, longer than broad; antennal insertions contiguous with the base of the mandibles, with an small obtuse tubercle on each side at the internal apex; eyes depressed, small, moderately coarsely faceted, deeply emarginate, each lobe consisting of three rows of facets, internal margin with a semicircular crest, an oblique, ventral and dorsal crest margining the depression of the eyes and with a distinct tubercle on each side at the lower margin of the depressions; genae short, projecting down and forward, apices obtuse; dorsal punctures deep, contiguous to confluent; setae present only at the posterior part of the eyes; mentum and ligula strongly slanting; maxillary palpi

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only slightly longer than labial, apical segments two times longer than previous one, obovate elongate with apex truncate; gula longitudinally convex, with dense transverse punctures and numerous erect setae; antennae 11­segmented, scape short, subpyriform, segments 2–10 subconical, third segment shorter than first, fourth to tenth subequal and slightly longer than third, eleventh slightly longer than the first, segments 2–10 with short, subdepressed setae, segments from third with pubescent sensory patches gradually increasing in size toward apex, the last segment completely covered. Pronotum slightly broader than long, sides broadly rounded, strongly constricted near base; apical margin slightly emarginate, basal slightly curved; disk with punctures deep, contiguous to confluent, with three, glabrous, longitudinal calluses, one median and one on each side of middle, calluses extending from base almost to apex; pubescence long, erect, golden, setae more numerous at sides. Scutellum semioval, longer than wide, slightly convex transversally, almost glabrous. Elytra 2.1 times longer than broad; sides parallel; base lightly arcuate; humeri round­ ed and lightly projecting forward; apices rounded; punctures deep and contiguous; erect setae uniformly distributed. Prosternum plane, almost twice as broad as long, punctures transversely confluent, forming shallow transverse rugae, erect setae numerous, intercoxal process flat, expanded apically, coxae rounded, coxal cavities closed behind; mesosternum narrow, twice as broad as long, punctures deep and contiguous, erect setae denser at sides, intercoxal process narrow, plane, notched at apex, coxal cavities closed to epimera; metasternum a little broader than long, deeply, contiguously punctuate, erect setae denser anteriorly and at sides, metepisternum narrow, tapering posteriorly. Legs short, setae erect, sparse on femora, denser on tibiae; femora enlarged at middle, flattened, punctures sparse, fine; tibiae flattened, expanded apically, dorsal and ventral face with small asperities each bearing an erect seta; protibiae with spatulate lobe on external apical angle and a carina which extends from the base to the apex of the external margin; meso­ and metatibiae with apical margin extended distally; tarsi 0.7 times as long as tibiae, first segment slightly shorter than fourth, last one longer than second and third together. Abdomen with segments gradually decreasing in width toward apex; punctures deep, contiguous; pubescence moderately dense, long, erect; fifth sternite broadly rounded at apex. Length 12.7, width 3.4 mm.

Male. Unknown.

Variation. Occasionally the lower eye lobes have four rows of facets. Length: 11.3–12.7 mm.

Diagnosis. This species is very distinctive and may be separated from the other known Erlandia by the coarse, dense punctures, eyes depressed and with three rows of facets on each lobe, the lateral projections below the eyes, pronotum with calluses on disc and without a median lateral tubercle and by the scutellum being longer than wide. In E. inopinata and E. megacephala the eyes are not depressed and the lower lobe is much bigger than the upper lobe, lack the projection below the eyes, the pronotum has a median lateral tubercle and the calluses on the disk are lacking and the scutellum is broader than long. In E. inopinata the vertex and disk of the pronotum are smooth with very fine punctures.

Etymology. Named for Mexico, the country of origin.

Holotype Female. Labeled: México: Oaxaca, 23.5 km SSE Cuicatlán, 17°37'.582N, 96°55'.121O, 24­III­1998, Alt. 940 m, Trampa de luz 2, S. Zaragoza, F. A. Noguera, A. Morales (deposited in Colección Nacional de Insectos, Instituto de Biología , UNAM, México). Two female paratypes with the same data except, 20­IV­1998, S. Zaragoza, V. H. Toledo, F. A. Noguera, M. A. Morales. Two additional female paratypes from México: Oaxaca, 26 km SSE Cuicatlán, 17°36'.998N, 96°55'.392O, 25­III­1998, Alt. 1,080 m, Trampa de luz 3, S. Zaragoza, E. Ramírez, M. E. Guardado . Paratypes deposited in EBCC and EMEC .

Biogeographical Comments. The presence of this species in México considerably extends the distribution of the Tribe Erlandiini in the Western Hemisphere and raises interesting biogeographical questions. The three species have been recorded only in the dry tropical communities, E. inopinata and E. megacephala in ‘‘El Chaco’’ ( Di Iorio 1998) a phytogeographic region of north central Argentina, western Paraguay and the southeast of Bolivia ( Sarmiento 1975). E. mexicana new species is found in the floristic province of the Valley of Tehuacán­Cuicatlán, which is situated in south central México between the states of Puebla and Oaxaca ( Villasenor et al. 1992). Hypotheses about distribution patterns of insects in México indicate that the endemic fauna of the Mexican Plateau have an ancient Neotropical origin (dispersion) ( Linsley 1961; Halffter 1976; Kohlman and Halffter 1988) or is a remnent of tropical biotas existing in America before the separation of North and South America (vicariance) (Michener and Grimaldi 1988; Noguera 1993). Under this context, Sarmiento (1975) has indicated that the dry tropical floras of southern South America (including ‘‘El Chaco’’) do not have a very close relationship with the flora of northern South America and that the later are more related, at least the Cactaceae , with the dry formations of México. This discontinuity supports the hypothesis of a very old divergence among these biota and that it is a result of an event of vicariance. However, stronger evidence is necessary for this to be more conclusive. A determination of the time of divergence among the species of Erlandia , would help to support or reject either of these hypotheses or both.

Figures

Fig. 1. Erlandia mexicana new species. Female, holotype.