Donus austerus (Boheman, 1834)

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 : 7-8

Donus austerus (Boheman, 1834)

Material. (5 mature larvae), collected in the field: PORTUGAL mer., prov. Algarve, 12 km S of Monchique (Serra da Monchique), 43 m a.s.l., 16.iv.2004, J. Skuhrovec leg. (5) (on Polygonaceae ).

Differential diagnosis. Mandible with three teeth (x D. crinitus , D. reichei and Hypera -species) ( Fig. 4 ). 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 to each other (x D. intermedius , D. oxalidis and D. tesselatus ) (all Fig. 5 ). 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 5-6 ). 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 only with one seta (prs) (x D. osellai ). 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. 6 ).

Description of mature larva.

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

HEAD. Head width 1.09 mm (1.05–1.18 mm), head length 1.00 mm (0.95–1.05 mm) ( Table. 1 ). Frontal sutures distinct, slender, anteriorly nearly indistinct. Anterior margin of clypeus distinctly concave ( Fig. 1 ) with weak pigmentation. Labrum pale brown; anterior margin with slender median excision, posterior margin with long and wide median projection ( Fig. 1 ). Mandibles with three sharp teeth apically ( Fig. 4 ), second tooth largest; basal part of mandible with distinct tuberosity.

THORAX. Spiracle with oval airtubes oriented posterio-dorsad.

ABDOMEN. Spiracles with oval airtubes oriented dorsad.

CHAETOTAXY. Head. Setae hairform. Des2 minutely shorter than des4; des2 about 0.6 x des1 and des5, approximately of same length; about 0.6 x des3 ( Fig. 1 ). Both les long, les1 about 0.7 x les2. Both ves short. Fs1 and fs3 minutely shorter than fs4; fs4 about 0.4 x fs5 ( Fig. 1 ). Both cls short, lrms1–3 short ( Fig. 1 ). Mds1 short, about 0.4 x mds2 ( Fig. 4 ). Sts1–2 long, sts3 about 0.5 x sts1–2 ( Fig. 2 ). Dms1–6 stout ( Fig. 3 ), vms1–5 minute. Mxps short. Plbs1 about 0.7 x long plbs2, plbs3 very short, about 0.3 x plbs1; prms as plbs1; both lig minute ( Fig. 2 ).

Thorax ( Fig. 5 ). Bases of setae strongly pigmented, setae unpigmented. Setae short, bacilliform to hairform (vpls, pda, msts). Prothorax: prn1–2 and prn9–10 short, about 0.5 x prn3–8, long, approximately of same length. Vpls1–2 short, approximately of same length. Pedal lobe with three (three to five) setae (pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to three) setae minute. Msts minute. Meso- and metathorax: prs long, pds1–4 short, about 0.5 x prs. Both dls and ss short as pds1–4. Dpls minutely longer than ss1–2. Vpls minutely longer than dpls. Pedal lobe with three (three to five) setae (pda); pda1–2 long, pda2 about 0.75 x pda1; remaining one (one to three) setae minute. Msts minute.

Abdomen. Bases of setae strongly pigmented, setae unpigmented. Setae long, bacilliform to hairform (vpls, lsts, msts). Abdominal segments I–VIII ( Fig. 6 ): pds1–5 approximately in line, pds2 positioned slightly anteriad; short, approximately of same length. Sps shorter than prs. Both dpls short, approximately of same length. Vpls2 longer than remaining setae on abdomin, vpls1 minute. Lsts long as vpls2, msts minute. Abdominal segment VII(VIII): pds3 longer than remaining setae, about 0.8 x. Abdominal segment IX ( Fig. 7 ): ds1–4 bacilliform; ds2–4 not in line, ds3 posteriad of line joining ds2 and ds4; ds3 the longest, remaining three setae approximately of same length, about 0.6 x ds3. Ps1–2 bacilliform, about 0.5 x ds1. Both sts hairform, sts1 minute, sts2 short.

Figures

FIGURES 1 – 7. Donus austerus. (1) head, (2) labium and maxilla, (3) maxilla, (4) mandible, (5) thorax, (6) abdominal segment IV, (7) abdominal segment IX; Figs 1, 3 – 4 dorsal view, Fig. 2 ventral view and Figs 5 – 7 lateral view. Scale bar 0.1 mm: a — Figs 5 – 7; b — Fig. 1; c — Figs 2 – 3; d — Fig. 4.