Mecinus desertorum (Korotyaev)

Caldara, Roberto & Fogato, Valter, 2013, Systematics of the weevil genus <i> Mecinus </ i> Germar, 1821 (Coleoptera: Curculionidae). I. Taxonomic treatment of the species, Zootaxa 3654 (1), pp. 1-105 : 39-40

19. Mecinus desertorum (Korotyaev)

Figs 17 , 62 , 121

Gymnaetron desertorum Korotyaev, 1995: 92 .

Mecinus desertorum (Korotyaev) . Caldara, 2001: 183.

Type locality. Przevalsk ( Kyrgyzstan).

Type series. This species was described from specimens collected in various localities from Kyrgyzstan, Kazakhstan and Mongolia which we examined ( ZISP).

Redescription. Male. Length 1.9 mm. Body: moderately long, oval, moderately slender ( Fig. 17 ). Rostrum: reddish brown, moderately short (Rl/Pl 0.76); in lateral view moderately curved, moderately narrowed from base to apex ( Fig. 62 ); in dorsal view with sides gradually convergent in basal third then subparallel, with hardly visible scrobes, sparsely striate-punctured at sides, smooth and moderately shining on dorsum, in basal half with recumbent to suberect, somewhat dense, white, long to very long (l/w 10–12), seta-like scales. Head: frons slightly wider than rostrum at base, with distinct fovea; eyes weakly convex. Antennae: reddish, inserted just in front of middle of rostrum; scape moderately short, 4.0x longer than wide; funicle slightly longer than scape, segment 1 twice as long as wide, slightly stouter and 1.2x longer than segment 2, which is twice as long as wide, segments 3– 5 about as long as wide; club moderately long, oval. Pronotum: brown and in part blackish brown on disc, with sparse punctures which are irregular in size (punctures in part very small) and disposition, intervals between punctures in part wider than punctures, rugose, opaque, moderately visible between recumbent (for the most part) to suberect, somewhat dense, light brown and greyish, very long (l/w 15–20), seta-like scales; weakly transverse (Pw/Pl 1.24), with moderately rounded sides, widest at middle, with weakly prominent apical constriction, weakly convex. Elytra: reddish brown with blackish brown interstria 1; moderately long (El/Ew 1.33), subrectangular, at base moderately concave, moderately wider than pronotum (Ew/Pw 1.33), with subparallel sides, weakly convex on disc; interstriae hardly visible between somewhat dense, greyish and greyish brown, very long (1.0–1.5x as long as width of interstria; l/w 15–20), seta-like scales, which are recumbent (for the most part and arranged in 2–3 very irregular rows) to suberect (longer than others and arranged in a somewhat regular single median row); striae hardly visible, one third narrower than interstriae, with a row of scales similar to shorter ones covering interstriae. Legs: moderately slender, with subrecumbent to erect, somewhat dense, whitish, long, seta-like scales, which are slightly shorter than or as long as width of tibia; femora reddish, clavate, with very small tooth; tibiae reddish, moderately slender, protibiae with apical part of ventral surface weakly directed outward; unci blackish, very stout, all equal in length; tarsi reddish, tarsomere 1 1.5x longer than wide, tarsomere 2 as long as wide, segment 3 not bilobed and as wide as tarsomere 2, onychium as long as tarsomeres 1–3 taken together; claws blackish, almost equal in length, fused in basal half. Venter: metasternum dark brown, clearly visible between sparse, whitish, long, hair-like scales; mesothoracic epimera and meso- and metathoracic episterna with sparse, whitish, in part narrow and seta-like and in part wide and fringed scales; abdomen dark brown with reddish ventrite 5, with shallow punctures, which are sparse and irregular in size (in part very small) and disposition, and clearly visible between sparse, whitish, long, seta-like scales; ventrites length ratio 1–2/3–4 1.70. Penis: fig. 121.

Female. As in male except rostrum longer (Rl/Pl 0.96) and more curved, antennae inserted between basal third and median third of rostrum, uncus of metatibiae slightly smaller than others, all tibiae with premucro. Sternite 8 and spermatheca: as in M. caucasicus ( Figs 145 and 158 ).

Variability. Length 1.9–2.1 mm. The blackish brown part of the integument on the pronotal disc may be more or less large. The elytra are moderately variable in length (El/Ew 1.32–1.39).

Remarks and comparative notes. This species differs from M. linnavuori by the antennal funicle with segment 2 about twice as long as wide, and from M. paratychioides by the shorter elytra, the rostrum being shorter in both sexes and not cylindrical in the male, the scrobes are distinctly visible in dorsal view. Moreover, it differs from both species by the larger eyes, that are rounded and not completely flattened.

Biological notes. Korotyaev (1994) collected one type specimen in Mongolia on Plantago minuta Pall.

Distribution. Kazakhstan, Kyrgyzstan, Mongolia.

Non-type specimens examined. None.

Figures

FIGURES 10–18. Habitus of (10) Mecinus longulus; (11) M. tychioides; (12) M. labilis; (13) M. plantaginis; (14) M. alboscutellatus alboscutellatus; (15) M. paratychioides; (16) M. linnavuori; (17) M. desertorum; (18) M. marina. Not to the same scale.

FIGURES 58–68. Rostrum in lateral view of (58) Mecinus alboscutellatus alboscutellatus; (59) idem, female; (60) M. paratychioides, male; (61) M. linnavuori, male; (62) M. desertorum, male; (63) M. henrici, male; (64) M. reichei, female; (65) M. marina, male; (66) idem, female; (67) M. elongatus; (68) idem, female. Scale bar = 0.5 mm.

FIGURES 121–132. Penis in dorsal and lateral view of (121) Mecinus desertorum; (122) M. marina; (123) M. henrici; (124) M. alternans; (125) M. reichei; (126) M. tanaiticus; (127) M. circulatus; (128) M. humeralis; (129) M. pyraster; (130) M. comosus; (131) M. simus; (132) M. pirazzolii. Scale bar = 0.2 mm.

FIGURES 144–156. Sternite 8 of (144) Mecinus pascuorum; (145) M. caucasicus; (146) M. marina; (147) M. reichei; (148) M. humeralis; (149) M. circulatus; (150) M. pyraster; (151) M. simus; (152) M. collaris; (153) M. janthinus; (154) M. lixoides; (155) M. sicardi; (156) M. heydenii. Scale bar = 0.2 mm.

FIGURES 157–171. Spermatheca of (157) Mecinus pascuorum; (158) M. caucasicus; (159) M. haemorrhoidalis; (160) M. labilis; (161) M. marina; (162) M. elongatus; (163) M. reichei; (164) M. circulatus; (165) M. pyraster; (166) M. simus; (167) M. comosus; (168) M. lixoides; (169) M. janthinus; (170) M. heydenii; (171) M. collaris. Scale bar = 0.2 mm.