Mecinus marina (Korotyaev, 1984)

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 : 40-41

Mecinus marina group

Diagnosis. Integument covered with broad scales on pronotum (especially at the sides), epimera, episterna, metasternum and ventrite 1. Claws free.

Remarks and comparative notes. No other species of Mecinus are characterized by a similar pattern of vestiture, However it is interesting to note that in Mecinus , as well as in Gymnetron and exceptionally in Rhinusa — R. mauritii ( Desbrochers des Loges, 1898) —several species, often unrelated, are covered to a greater or lesser extent in broad scales. In the genus Mecinus , M. plantaginis (unique in the M. pascuorum complex) and M. collaris has broad scales at the sides of pronotum and at the base and sides of pronotum and part of epimera and episterna, respectively.

20. Mecinus marina (Korotyaev)

Figs 18 , 65–66 , 122 , 146 , 161

Gymnetron marina Korotyaev, 1984: 349 . Arzanov, 1991: 428.

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

Type locality. Sea of Azov coast N of the Sadki Village , 12 km SSE of the town Primorsko-Akhtarsk (Krasnodar Territory, Russia).

Type series. This species was described from specimens collected on the coast of the Krasnodar Territory and in Kalmykia ( Russia), which we examined ( ZISP).

Redescription. Male. Length 1.8 mm. Body: moderately long, oval, moderately slender ( Fig. 18 ). Rostrum: blackish with reddish apex, moderately long (Rl/Pl 0.90); in lateral view weakly curved at base then almost straight to apex, gradually and weakly narrowed from base to apex ( Fig. 65 ); in dorsal view with sides weakly narrowed in basal third then subparallel, with weakly visible scrobes, in basal two thirds moderately striatepunctured, in basal half with recumbent, somewhat dense, greyish white, somewhat short (l/w 2–4), rectangular scales. Head: frons weakly narrower than rostrum at base, with distinct fovea; eyes nearly flat. Antennae: reddish with dark brown club, inserted just in front of middle of rostrum; scape elongate, 5.0x longer than wide; funicle slightly longer than scape, segment 1 1.5x longer than wide, distinctly stouter and as long as segment 2, which is twice as long as wide, segment 3 as long as wide, segments 4 and 5 moderately transverse; club moderately long, oval, segment 1 almost glabrous. Pronotum: black, with dense and regular punctures, intervals between punctures narrow, hardly visible between recumbent, moderately dense, greyish, moderately long (l/w 3–5), elliptical scales on disc, and recumbent, dense, yellowish grey, short (l/w 1–1.5), fringed scales at sides and base; moderately transverse (Pw/Pl 1.38), with weakly rounded sides, with weakly prominent apical constriction, widest between basal third and median third, weakly convex. Elytra: reddish except interstria 1 and median third of interstriae 4 and 5, which are black; moderately short (El/Ew 1.32), suboval, at base somewhat concave, distinctly wider than pronotum (Ew/Pw 1.47), with moderately rounded sides, widest at middle, moderately convex on disc; interstriae clearly visible between recumbent, sparse, greyish, moderately long, linear to subtriangular scales, which are confusedly arranged; striae hardly visible, as wide as half of interstriae, formed by shallow punctures, with intervals between punctures on the same plane of interstriae, with a row of scales slightly thinner than those covering interstriae. Legs: somewhat slender, with recumbent to subrecumbent, sparse, whitish, narrow but not seta-like scales, which are distinctly shorter than width of tibia; femora reddish, subclavate, all with thin sharp tooth; tibiae reddish, slender, protibiae with apical part of ventral surface weakly directed outward; unci black, stout, all equal in length; tarsi reddish, tarsomere 1 1.5x longer than wide, tarsomere 2 1.2x longer than wide, tarsomere 3 bilobed and moderately wider than tarsomere 2, onychium as long as tarsomeres 1–3 taken together; claws dark brown, equal in length, free from base. Venter: metasternum black, moderately visible between somewhat dense, whitish, in part wide and in part narrow, setalike scales; mesothoracic epimera and meso- and metathoracic episterna with dense, whitish, wide scales; abdomen with ventrites 1 and 2 black and others reddish, with moderately dense and regular punctures, which are clearly visible between sparse, whitish scales, which are seta-like for most part and wide at sides of ventrite 1; ventrites length ratio 1–2/3–4 2,12. Penis: fig. 122.

Female. As in male except rostrum longer (Rl/Pl 1.05), in lateral view more straight ( Fig. 56 ), antennae inserted just before middle of rostrum. Sternite 8: fig. 146. Spermatheca: fig. 161.

Variability. Length 1.7–2.0 mm. Sometimes the elytra are more largely black from interstria 1 to interstria 5 in their apical half or completely reddish; in this case the femora are blackish brown.

Remarks and comparative notes. This species is related to M. henrici by the characters reported in the diagnosis of the group. However the differences between these two species are noteworthy. In fact M. marina is easily distinguishable from M. henrici by numerous characters like elongate oval shape of the body, tarsomere 3 distinctly bilobed and wider than tarsomere 2, recumbent elytral scales, pronotum only moderately transverse and distinctly narrower than elytra, anterior margin of the pronotum with scales distinctly smaller than those covering the sides, rostrum in male almost straight from base. The shape of the penis is also markedly different in the two species: in M. marina it is distinctly bigger, although the two species are similar in size, and shorter and wide like that of the species related to M. circulatus , whereas in M. henrici the penis does not show noteworthy differences from that of the species of the M. pascuorum complex. Finally, the shape of the spermatheca, characterized by sclerotized spermathecal duct, is noteworthy. Due to the shape of the body, the colour of the integument and the pattern of the dorsal vestiture, mainly characterized by wide scales covering sides and base of pronotum, M. marina is similar to the species of Gymnetron related to G. veronicae Germar, 1821. Apart from the shape of the terminalia and the characters allowing for the separation of these genera, in addition to the host plant being Plantago , M. marina differs from these species by the claws which are free from the base, and by the toothed femora.

Biological notes. Arzanov (1991) quoted that this species was collected in southern Russia (Krasnyi Manyc) on Plantago tenuifolia Waldst. & Kit.

Distribution. Southern Russia.

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.

FIGURES 43–57. Rostrum in lateral view of (43) Mecinus pascuorum, male; (44) idem, female; (45) M. ictericus, female; (46) M. caucasicus, male; (47) idem, female; (48) Mecinus variabilis, male; (49) idem, female; (50) M. haemorrhoidalis, male; (51) idem, female; (52) M. seriatus, female; (53) M. longulus, female; (54) M. tychioides, male; (55) M. labilis, male; (56) idem, female; (57) M. plantaginis, male. Scale bar = 0.5 mm.