Two new species of Teratembiidae (Embriidina) from Argentina
1991; BioOne; Volume: 99; Linguagem: Inglês
ISSN
1937-2361
Autores Tópico(s)Fossil Insects in Amber
Resumo-Both sexes of two new species of Teratembiidae from Argentina, are described and illustrated. Oligembia mini, n. sp. is closest to Oligembia bicolor Ross, 1944. Diradius erba, n. sp. is closest to Oligembia unicolor Ross, 1944 (which seems to belong to Diradius). Embiidina is a group well defined by a series of morphological and behavioral characters (Ross, 1970; Hennig, 1981). Most of the characters considered important for species recognition in this group refer to male characters, mainly terminalia, coloration, form and size of eyes, wing venation, and size and number of papillae on the hind basitarsus. The only female characters mentioned in the literature to distinguish species are total length, coloration, and number of papillae on the hind basitarsus (Ross, 1944, 1970). However, the hind basitarsus chaetotaxy, and the form and position of papillae in females (previously illustrated for males of some species, in papers by Krauss, 1911; Davis, 1939a, b, 1940a, b, 1942; Ross, 1957, 1971) also present specific differences; in the description of two species of Teratembiidae from Argentina, those characters are used for the first time in females. These characters are also used in the males of the two new species and also in those of 0. unicolor and 0. bicolor. MATERIALS AND METHODS All measurements are given in millimeters. Ocular ratio is defined as the ratio between minimum distance between inner edges of eyes, and maximum distance of outer edges, in dorsal view. The material examined is deposited in the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN) and in the Facultad de Ciencias Exactas y Naturales de la Universidad de Buenos Aires (FCEN). Abbreviations used follow Ross (1944 and subsequent papers): 9T, ninth abdom inal tergite; lOT, tenth abdominal tergite; lOL, left hemitergite of tenth abdominal tergite; 1 OR, right hemitergite of tenth abdominal tergite; MS, medial sclerite of tenth abdominal tergite; 1OLP, process of left hemitergite; lORP, process of right hemi tergite; EP, epiproct; LPPT, left paraproct; RPPT, right paraproct; H, hypandrium or ninth abdominal sternite; HP, process of ninth sternite; LCB, left cercus-basipodite; RCB, right cercus-basipodite; LCBP, process of left cercus-basipodite. Descriptions are based on only one specimen; variation observed on other spec imens is pointed out separately, with the mean value followed by standard deviation and range, in parentheses; for proportions, only the range is given. Setae are omitted in the drawings of terminalia. This content downloaded from 207.46.13.118 on Sun, 11 Sep 2016 06:12:46 UTC All use subject to http://about.jstor.org/terms 612 JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY Vol. 99(4) Genus Diradius Friederichs, 1934 According to Ross (1984b:45) this genus differs from Oligembia Davis by the following characters of the male terminalia: 1-... complete absence of lines between lOL, lOR and medial sclerite (MS) . 2-... outer side of the right hemitergite (1OR) ... at least as long as outer margin of lOL .... 3-... usual presence of lobe beneath the claw-bearing lobe of the left cercus-basipodite .... The only character that really distinguishes Diradius from Oligembia (and all the embidiina) is the last one, previously mentioned by Ross (1944:476) as LCB with two inner lobes, the ventral one usually shorter and broadly pointed, the upper lobe enlongate with a terminal cleft forming rather long claws which may at times be fused together .... Species transferred by Ross (1984a:90) to the genus Diradius lack the former two characters mentioned. Diradius lobatus (Ross, 1944: fig. 128); Diradius excissa (Ross, 1944: fig. 139); Diradius plaumanni (Ross, 1944: fig. 143); Diradius vandikei (Ross, 1944: fig. 152); Diradius nigrina (Ross, 1944: fig. 149), have a fusion line between 1 OL and MS. Although some species of Diradius differ from Oligembia in this char acter, the same is not true for all the species in the genus. The situation is similar with regard to the outer margin of the lOR. Diradius chiapae (Ross, 1944: fig. 137), D. excissa (Ross, 1944: fig. 140) and D. nigrina (Ross, 1944: fig. 150), have the outer margin of the 1 OR slightly shorter than the outer margin of the 1 OL, and species as D. plaumanni (Ross, 1944: fig. 143), D. gigantea (Ross, 1944: fig. 146), D. vandykei (Ross, 1944: fig. 152) and D. caribbeana (Ross, 1944: fig. 155), have the outer margin of the lOR clearly shorter than that of the 1 OL. Diradius erba, new species (Figs. 1, 5, 9, 11, 17, 18, 21, 23, 29) Diagnosis. Diradius erba is closest to Oligembia unicolor Ross, 1944. Diradius erba has the apex of LCBP with lateral margins convergent and straight, with two blunt apical spines, the anterior margin of the submentum with two triangular mesial projections, the margin of lOL, lOR and MS with depressions towards the base of 1 ORP, marked by deep lines. Oligembia unicolor, instead, has the apex of LCBP with lateral margins irregular and divergent, forming a circular plate with two projecting spines, the anterior margin of submentum rounded, and the margin of 1 OL, 1 OR and MS without depressions. Types. Holotype male (in alcohol) from Argentina, Entre Rios Prov., Balneario La Lana, 5 6 XII 1987, C. Szumik, P. Goloboff col. (MACN) Paratypes: three males, same data as the holotype (MACN); male and female from Argentina: Buenos Aires Prov., Otamendi, INTA Delta, 14 15 XII 1988, C. Szumik, A. Valverde col. (MACN). Etymology. The specific name is formed with the initials of the provinces where the species has been collected. Male holotype. Total length: 4.90. Head (Fig. 1): rectangular, width/length, 0.68. Eyes very small, ocular ratio: 0.74. Mandibles (Fig. 1): left with three very short, inconspicuous teeth in the tip; inner margins with a very sharp and conspicuous basal tooth. Submentum: anterior margin with two short triangular projections and a small notch between them (Fig. 5). Wing lengths: anterior, 3.40; posterior, 2.75. Wing venation similar to the venation illustrated by Marifio and Marquez (1982: This content downloaded from 207.46.13.118 on Sun, 11 Sep 2016 06:12:46 UTC All use subject to http://about.jstor.org/terms 1991 NEW TERATEMBIIDAE 613
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