Neoathyreus fallolobus, Howden, Henry F., 2006

Howden, Henry F., 2006, New species and a new subgenus of South American Neoathyreus Howden and Martínez (Coleoptera: Geotrupidae: Athyreini), Zootaxa 1137, pp. 37-52 : 45-48

Neoathyreus fallolobus , new species ( Figs. 12–15 )

Holotype. Male, length 14.9 mm, greatest width 8.7 mm. Dorsally black, surface with scattered, erect, pale setae. Clypeus ( Fig. 12 ) with longitudinal, median horn arising anteriorly and extending length of clypeus; lateral horn or tubercle on each side above antennal insertion almost same height as median horn; anterior carina on each side curved abruptly upward near median horn and extending up one­half anterior face of horn; posterior carina on each side arcuately depressed between horns; surface of clypeus on each side shallowly concave, contiguously punctate­rugose. Vertex punctate­rugose anteriorly near horns, closely granulate elsewhere, surface slightly convex between eyes. Gena with slightly reflexed outer margin, anterior lateral angle with small tubercle, surface of gena tuberculate. Pronotum ( Fig. 12 ) with small, shallow fossa on each side behind eye adjacent to margin, fossa slightly wider than width of marginal bead; anterior marginal bead gradually, arcuately raised between fossae, midline constricted by very small indentation, lacking tubercle or angulation. Pronotum with inner carina on each side arising about 1.0 mm posterior to fossa; carina gradually bowed inwardly and becoming wider to rounded end about 0.3 mm from posterior midline; outer edge of carina elevated; between inner posterior edges of carina with very small tubercle on midline. Concavity ( Fig. 12 ) between inner carinae deep in anterior half, abrupt, posterior edge of deep depression broadly v­shaped, extending in posterior half as shallowly impressed midline, posterior half of concavity shallow, sloping evenly to midline. Outer carina on each side 1.0 mm long, very narrow, about 0.1 mm wide or less, slightly sinuous, inconspicuous. Lateral pronotal marginal bead complete, not broken or obviously indented; entire surface of pronotum except for carinae closely, rather coarsely granulate. Elytron with several striae slightly indicated at base, surface closely punctate­rugose except for smooth surface of humeral umbone. Metasternum between middle coxae slightly convex, midline shallowly impressed; anterior end of metasternal midline sharply, almost acutely angled, angle becoming broadly obtuse; surface on either side of midline punctate, most punctures separated by about two diameters; some punctures each with long seta. Foretibia with five teeth on outer margin. Male genitalia as in Figs. 14, 15 , similar to those of male N. lobus Howden.

Allotype. Female, length 13.6 mm, greatest width 8.1 mm. Similar to male except as follows: median clypeal horn ( Fig. 13 ) reduced to large tubercle at anterior edge of clypeus, extending posteriorly as low ridge along midline to join slightly developed posterior carina; carina bowed downward between lateral horn or large tubercle on each side, horn 2–3 times height of median tubercle; posterior carina near midline only slightly developed. Pronotum with tubercle between posterior ends of inner carina reduced to low, rounded swelling no higher than inner edge of adjacent carina; outer carina almost obsolete, represented by narrow row of 4–5 fused tubercles. Pygidium more broadly rounded, briefly emarginate medially.

Type Series. Holotype, male, Peru, Cusco: San Pedro, 13 0 3'15" S 71 32' 54" W, 1500 m, 17,18. XI.1999, T. Larsen, Cloud forest, F.I.T. 1 ( CMNC). Allotype, female, Peru, Cusco: Iskaybamba coffee plantation, 1835 m, 13 30' 16.3" S 70 53' 58.7" W, 29,30. V.2000, T.Larsen, F.I.T. ( HAHC). Paratypes, 3 males: 1, same data as holotype except 19,20. XI.1999; 2, same data as holotype except 18,19. XI.1999, F.I.T. 2. Paratypes are in: HAHC.

Remarks. Variation in the length of the three male paratypes ranges from 10.0 to 12.5 mm and greatest width from 6.5 to 7.6 mm. The smallest male is dark brown (possibly teneral) and has the clypeus shaped like the allotype; the lateral horns are reduced to tubercles, smaller than in the allotype. In two of the three males, both small, the anterior pronotal depression in the concavity, while still evident, is reduced in depth and the inner carinae are only slightly wider posteriorly. In the largest male paratype the posterior pronotal tubercle between the ends of the inner carinae is only represented by a smooth granule; in the smaller males the tubercle is absent. The lateral carinae are absent in one male and only slightly indicated in the other two. Dorsal setae vary in density, perhaps because of immersion in the F I T fluid or because of abrasion. There are also slight differences in the positioning in the apical lobes of the male genitalia.

Large males and possibly some large females will key, with some difficulty because of their uniform black color, to couplet 16 in my 1985 revision; this couplet includes N. corniculatus (Felsche) from Venezuela and N. lobus Howden from Argentina. Smaller specimens that lack the posterior pronotal tubercle will not key beyond couplet 13, and specimens that also lack the outer pronotal carinae will not key beyond couplet 10. However, N. fallolobus can be identified by the following combination of characters: uniform dorsal color, unusual clypeus with longitudinal median ridge, lack of an anterior pronotal tubercle and with small or no posterior tubercle, deep depression in the anterior half of pronotal concavity, surface of pronotum, except carinae, closely granulate or punctate, lateral pronotal marginal bead unbroken, and with five teeth on outer edge of foretibia. No other described species of Neoathyreus has this combination of characters.

The “ lobus ” complex of forms in southern South America presents some interesting problems, possibly related to geographic variation. The type locality of N. lobus is the Argentine province of Catamarca; other typical specimens have been taken in Tucumán. All of these specimens have the anterior pronotal marginal bead medially thickened and with a median, posteriorly directed, obtuse angulation. In specimens from northern Salta and Jujuy, Argentina, the anterior pronotal bead is only slightly thickened and lacks the obtuse angulation. All Argentine specimens dorsally are either bicolored light to dark brown or entirely brown to dark brown. In Cochabamba, Bolivia, on the eastern slopes of the Andes, specimens are dorsally uniformly black, the anterior pronotal bead is uniformly thin, and the posterior pronotal tubercle is pronounced but slightly more slender than in Argentine specimens. All of these “forms” have similar genitalia, as does N. fallolobus . With the material at hand, it is obvious that more material from different localities is needed to determine if the variation is clinal or if several species are involved.

Etymology. The combination of “fallo” meaning “false” and “ lobus ”, referring to the posterior pronotal tubercle in the described species, is intended to indicate the relationship between these two species based on a comparison of morphological characters.

Figures

FIGURES 12 – 15. Neoathyreus fallolobus, n. sp.: 12, Male head and pronotum, dorsal view; 13, Female head and pronotum, lateral view; 14, Male genitalia, dorsal view; 15, Male genitalia, lateral view. Scale lines for genitalia = 0.2 mm.