Arvelius thomasi Ortega-León and Chávez-Bermeo, 2008

Arvelius thomasi Ortega-León and Chávez-Bermeo , new species

( Figs. 1–2, 7)

Description.—General coloration ochraceus to golden yellow. Mesial and lateral margins of juga, dorsal line on antennal segment I, rostral segment, and apex of tarsal claws dark brown; antennal segments II and III with small dark punctures; larger bluish punctures present on mesial margins of eyes, along basal two-thirds of anterolateral pronotal margins, scutellum and base of each conexiva segment; a small brown macula near posterior margin of each spiracle; ocelli red. Total length of male holotype 12.0

Head: Total length 1.6; preocular distance 1.0; interocular distance 1.2; width across eyes 2.0; interocellar distance 0.8; length of antennal segments: I, 0.8; II, 1.1; III, 1.4; IV, 1.9; V, 2.7. Juga longer than tylus, lateral margins slightly concave each tapering to acutely pointed apex. Rostrum reaching to middle of abdominal sternite V.

Pronotum: Length 1.9; width across anterior angles 2.4; width across humeral angles 7.2; posterior, posterolateral, and anterolateral margins slightly sinuous, humeral angles produced into thin and acuminately spinose, slightly elevated; anterolateral margins slightly concave and posterolateral margins straight.

Scutellum: Length 4.1; basal width 3.4; triangular, apex rounded.

Legs: Hind tibia with small spine on middle third; femora with three small spines, two apical lateral and one near mesial.

Male genitalia: Pygophore semirectangular, slightly longer than wide; dorsal margin nearly straight, ventral margin rounded; lateral lobule rounded especially on middle third. Paramere with sinus very slightly concave, with lobe on middle third of external margin; upper margin curved and extending into round lobe; internal margin with semiconical lobe; without ‘‘F’’ or beak shape as described by Brailovsky (1981).

Holotype.— ♂ México: Morelos, 2.5 km al Oeste de Huautla Estación CEAMISH 9/VI/1996, S. Zaragoza. Deposited in the Insect Collection of Instituto de Biología, UNAM ( CNIN).

Etymology.—We take great pleasure in naming this species for Dr. Donald Byron Thomas, pentatomid specialist at the Subtropical Agricultural Research Center, U.S. Department of Agriculture, as a token of gratitude for his consistent support.

Discussion.— Brailovsky (1981) recorded four species from Mexico: Arvelius albopunctus, A porrectispinus, A. tecpanus, and A. tuxtlaensis. Arvelius albopunctatus is the most widely distributed, extending from southern United States, through Mexico, Central America , the West Indies, and reaching northern Argentina. In Mexico, it is reported from Baja California, Chiapas, Chihuahua, Colima, Distrito Federal, Guerrero, Jalisco, Michoacán, Morelos, Nayarit, Nuevo León, Oaxaca, Puebla, San Luis Potosí, Sinaloa, Sonora, Tamaulipas, Veracruz, and Yucatán. Arvelius porrectispinus is distributed from southern United States to Brazil; in Mexico it has been found in Chiapas, Puebla, San Luis Potosí, and Veracruz. Arvelius tecpanus has been found in the Mexican states of Guerrero, Jalisco, and Oaxaca, while Arvelius tuxtlaensis has been recorded only from Veracruz and Arvelius thomasi has been found only in Morelos. The latter three species may be endemic to Mexico.

Arvelius thomasi is the smallest of the Mexican species; the length of body of the male is 12 mm while A. albopunctatus, A. porrectispinus, A. tecpanus, and A. tuxtlaensis is between 13.7 and 15.3; A. thomasi resembles A. tuxtlaensis in the shape of the humeral angles which are produced into thin, acuminate spines, while in A. thomasi the spines are short, thick, and nearly straight Fig. 1.

Arvelius thomasi is differentiated from the other four species of Arvelius of México by having an ochraceous thin dorsal line on antennal segment I Fig. 1. In A. porrectispinus, the line on antennal segment I is wider and laterally situated, while in A. tecpanus and A. tuxtlaensis it is a dorsal line on segments II and III (but not in I) and A. albopunctatus lacks a line.

The paramere of A. thomasi ( Fig. 7) is not F-shaped as in A. albopunctatus ( Fig. 9) and A. tecpanus ( Fig. 10) nor beak-shaped as in A. porrectispinus ( Fig. 8) and A. tuxtlaensis ( Fig. 11).