Donus osellai Winkelmann, 2001

Skuhrovec, Ji Ř Í, 2007, Descriptions of larvae of the tribe Hyperini (Coleoptera: Curculionidae): III. Mature larvae of the genus Donus Jekel, 1865, Zootaxa 1606, pp. 1-28 : 15-17

Donus osellai Winkelmann, 2001

Material. (8 mature larvae), collected in the field: ITALY bor., Sella Nevea, Monte Canin, 1800–2000 m a.s.l., 26.vi.2004, H. Winkelmann leg. (8) (on Achillea clavennae L.).

Differential diagnosis. Mandible with three teeth (x D. crinitus , D. reichei and Hypera -species) ( Fig. 39 ). Prs and pds1–4 on thoracic segments bacilliform (x D. comatus , D. cyrtus , D. oxalidis , D. palumbarius and D. tesselatus ). Pds2 on dorsum of meso- and metathorax not the shortest seta (x D. palumbarius and D. tesselatus ). Pds2 and pds3 on meso- and metathorax not close each other (x D. intermedius , D. oxalidis and D. tesselatus ) (all Fig. 40 ). Prn, prs and pds1–4 on thoracic segments and prs, pds1–5 on abdominal segments I–VIII short (x D. cyrtus , D. intermedius and D. oxalidis ) ( Figs 40–41 ). Prs and pds1–5 on abdominal segments I– VIII bacilliform or clubform (x D. comatus , D. cyrtus and D. oxalidis ). Prodorsum of abdominal segments I– VII with two setae (prs1–2) (x D. austerus , D. comatus , D. crinitus , D. cyrtus , D. osellai , D. oxalidis , D. palumbarius , D. reichei and D. tesselatus ). Pds 1–5 in line on abdominal segments I–VII, not pds2 positioned anteriad to pds3 and pds4 anteriad to pds5 (x D. cyrtus , D. intermedius , D. oxalidis and D. tesselatus ). Pds4 on dorsum of abdominal segments I–VI not the longest seta (x D. palumbarius ) (all Fig. 41 ).

Description of mature larva.

COLORATION. Head orange, posterior and lateral margins of epicranium dark. Dorsal side of body pale caesious with slightly white median stripe.

HEAD. Head width 0.77 mm (0.75–0.80 mm), head length 0.69 mm (0.68–0.70 mm) ( Table. 1 ). Frontal sutures distinct, slender, anteriorly nearly indistinct. Anterior margin of clypeus distinctly concave ( Fig. 36 ) with strong pigmentation. Labrum dark brown; anterior margin with deep median excision, posterior margin with short and wide median projection ( Fig. 36 ). Mandibles with three sharp teeth apically ( Fig. 39 ).

THORAX. Spiracle with oval airtubes oriented posterio-dorsad.

ABDOMEN. Spiracles with oval airtubes oriented postrio-dorsad.

CHAETOTAXY. Head. Setae hairform. Des2 minutely shorter des4, des4 about 0.8 x des5, des5 about 0.7 x des1 and des3 ( Fig. 36 ). Both les long, approximately of same length. Both ves short. Fs1 the shortest, about 0.7 x fs3; fs3 about 0.7 x fs4; fs4 about 0.7 x fs5 ( Fig. 36 ). Both cls short, lrms1–3 short ( Fig. 36 ). Both mds short ( Fig. 39 ). Sts1–2 long, sts3 very short ( Fig. 37 ). Dms1–6 stout ( Fig. 38 ), vms1–5 minute. Mxps minute. Plbs2 short, plbs1, 3 very short, about 0.3 x plbs2; prms long as plbs1; both lig minute ( Fig. 37 ).

Thorax ( Fig. 40 ). Bases of setae strongly pigmented, setae unpigmented. Setae short, clubform or bacilliform to hairform (dpls, vpls, pda, msts). Prothorax: prn1, 7 very short, about 0.5 x remaining setae on pronotum. Vpls2 about 0.5 x vpls1. Pedal lobe with three (three to five) setae (pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to three) seta minute. Msts minute. Meso- and metathorax: pds2, pds4 on mesothorax and pds2–4 on metathorax short, about 0.5 x prs, pds1, 3 on mesothorax and prs, pds1 on metathorax. Dls1–2 not closed each other; dls1 short as pds4, dls2 longer than dls1, about 1.3 x. Ss long as dls1. Dpls and vpls long as dls2. Pedal lobe with three (three to five) setae (pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to three) seta minute. Msts minute.

Abdomen. Bases of setae strongly pigmented, setae unpigmented. Setae short, clubform or bacilliform to hairform (dpls, vpls, lsts, msts). Abdominal segments I–VIII ( Fig. 41 ): pds1–5 approximately in line, pds2 and pds4 positioned slightly anteriad; pds2–5 short, about 0.6 x pds1. Prs1 long as pds1, prs2 short as pds2. Sps long as prs2. Both dpls long as pds1. Vpls2 long, vpls1 minute. Lsts long as dpls1–2, msts minute. Abdominal segment VII: pds2 and pds4 positioned slightly anteriad, pds3 slightly posteriad. Abdominal segment VIII: pds2 and pds4 positioned more anteriad from line joining pds1 and pds5 than on abdominal segments I–VII, pds4 positioned more anteriad than pds2; pds1, pds3 and pds5 approximately in line; pds3 longer than remaining setae. Abdominal segment IX ( Fig. 42 ): ds1–4 bacilliform; ds 2–4 in line; ds3 the longest, remaining three setae approximately of same length. Both ps bacilliform; shorter than ds1–4, about 0.5 x. Both sts hairform, sts1 very short, sts2 minute.

Figures

FIGURES 36 – 42. Donus osellai. (36) head, (37) labium and maxilla, (38) maxilla, (39) mandible, (40) thorax, (41) abdominal segment IV, (42) abdominal segment IX; Figs 36, 38 – 39 dorsal view, Fig. 37 ventral view and Figs 40 – 42 lateral view. Scale bar 0.1 mm: a – Figs 40 – 42; b – Fig. 36; c – Figs 37 – 38; d – Fig. 39.