Donus intermedius (Boheman, 1842)

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 : 12-14

Donus intermedius (Boheman, 1842)

Dieckmann 1989: 98.

Material. (5 mature larvae), collected in the field: SLOVAKIA mer. (7677), Č ajkov env., vill. Rybnik, 25.v.2002, J. Skuhrovec leg. (5) (on Centaurea jacea L.).

Differential diagnosis. Mandible with three teeth (x D. crinitus , D. reichei and Hypera -species) ( Fig. 32 ). Prn, prs and pds1–4 on thoracic segments bacilliform (x D. comatus , D. cyrtus , D. oxalidis , D. palumbarius and D. tesselatus ). Pds2 and pds3 on meso- and metathorax close each other (x D. austerus , D. comatus , D. crinitus , D. cyrtus , D. osellai , D. palumbarius and D. reichei ) (all Fig. 33 ). Prn, prs and pds1–4 on thoracic segments and prs, pds1–5 on abdominal segments I–VIII very long (x D. austerus , D. comatus , D. crinitus , D. osellai , D. palumbarius , D. reichei and D. tesselatus ) ( Figs 33–34 ). Prs and pds1–5 on abdominal segments I– VIII bacilliform (x D. comatus , D. cyrtus , D. oxalidis and D. tesselatus ). Prodorsum of abdominal segments I– VII only with one seta ( prs) (x D. osellai ). Pds1–5 on abdominal segments I–VII not in line, pds2 positioned anteriad to pds3 and pds4 anteriad to pds5 (x D. austerus , D. comatus , D. crinitus , D. osellai , D. palumbarius and D. reichei ). Pds4 on dorsum of abdominal segments I–VI not the longest seta (x D. palumbarius ) (all Fig. 34 ).

Description of mature larva.

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

HEAD. Head width 1.08 mm ( 1.05–1.13 mm), head length 1.01 mm ( 0.98–1.05 mm) ( Table. 1 ). Frontal sutures distinct, slender, anteriorly nearly indistinct. Anterior margin of clypeus distinctly concave ( Fig. 29 ) with weak pigmentation. Labrum pale brown; anterior margin with deep median excision, posterior margin with short and wide median projection ( Fig. 29 ). Mandibles with three sharp teeth apically ( Fig. 32 ).

THORAX. Spiracle with oval airtubes oriented postrio-dorsad.

ABDOMEN. Spiracles with oval airtubes oriented postrio-dorsad.

CHAETOTAXY. Head. Setae hairform. Des2 minutely shorter than des4; des4 about 0.7 x remaining three setae ( des1, des3, des5) ( Fig. 29 ). Both les long, approximately of same length. Both ves short. Fs1 and fs3 shorter than fs4, about 0.7 x; fs4 about 0.8 x fs5 ( Fig. 29 ). Both cls long, lrms1–3 short ( Fig. 29 ). Both mds short ( Fig. 32 ). Sts1–2 long; sts3 short, about 0.6 x sts1–2 ( Fig. 30 ). Dms1–6 stout ( Fig. 31 ), vms1–5 minute. Mxps very short. Plbs1–2 long, plbs3 short, about 0.6 x plbs1–2; prms minutely longer than plbs3; both lig very short ( Fig. 30 ).

Thorax ( Fig. 33 ). Bases of setae strongly pigmented, setae unpigmented. Setae long, bacilliform to hairform ( vpls, lsts, msts). Prothorax: prn2–10 very long; prn1 shorter than remaining setae, about 0.7 x. Vpls2 about 0.5 x vpls1. Pedal lobe with three (three to six) setae ( pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to four) setae minute. Msts minute. Meso- and metathorax: prs and pds1–4 very long, approximately of same length; pds1–4 not in line, pds2 positioned anteriad to pds3. Both dls long, close each other; ss1–2 distinctly shorter than dls1–2. Dpls as long as dls; vpls minutely shorter than dpls. Pedal lobe with three (three to six) setae ( pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to four) setae minute. Msts minute.

Abdomen. Bases of setae strongly pigmented, setae unpigmented. Setae short, bacilliform to hairform ( dpls, vpls, lsts, msts). Abdominal segments I–VIII ( Fig. 34 ): pds1, pds3 and pds5 approximately in line, pds2 positioned anteriad to pds3 and pds4 anteriad to pds5; prs and pds1, 3 and 5 very long, pds2 and pds4 shorter than remaining setae, about 0.8 x. Sps long, about 0.4 x prs. Both dpls short as sps. Vpls2 long, vpls1 minute. Lsts short, msts minute. Abdominal segment VII: pds2 positioned more anteriad to pds3 and pds4 more anteriad to pds5; pds3 the longest, pds2 and pds4 about 0.7 x. Abdominal segment VIII: pds2 and pds4 positioned more anteriad from line joining pds1 and pds5 than on abdominal segments I–VIII; pds3 very long, pds2 and pds4 about 0.7 x. Abdominal segment IX ( Fig. 35 ): ds 2–4 in line; ds4 the longest, remaining three setae approximately of same length. Both ps long, about 0.5 x ds1–3. Sts1 short, sts2 minute.

Remarks. Dieckmann (1989) recorded only coloration of the body and setae; his data agree with that presented here.

Figures

FIGURES 29 – 35. Donus intermedius. (29) head, (30) labium and maxilla, (31) maxilla, (32) mandible, (33) thorax, (34) abdominal segment IV, (35) abdominal segment IX; Figs 29, 31 – 32 dorsal view, Fig. 30 ventral view and Figs 33 – 35 lateral view. Scale bar 0.1 mm: a – Figs 33 – 35; b – Fig. 30 – 31; c – Figs 29; d – Fig. 32.