Sitona obsoletus (Gmelin, 1790)

Sprick, Peter, 2017, Description of the larvae and pupae of eight species of the tribe Sitonini Gistel, 1848 (Coleoptera, Curculionidae) from Central Europe, Zootaxa 4324 (3), pp. 401-435 : 414

Sitona obsoletus (Gmelin, 1790)

( FIgS 2–8g )

Body. LeNgTH 5.0–5.8 MM, WIDTH 1.3–1.7 MM. SeTAe VeRY lONg TO SHORT. PROTHORAX ( FIg. 2g ) WITH 11 prns, 4 OF THeM PlAceD clOSe TO SPIRAcle. MeSO- AND MeTATHORAX ( FIg. 2g ) eAcH WITH 1 SHORT prs AND 4 pds, AlMOST eQUAl IN leNgTH, eps MeDIUM lONg. EAcH PeDAl AReA WITH 5 pda, DIFFeReNT IN leNgTH. AbD. VIII ( FIg. 4g ) WITH 1 VeRY SHORT prs AND 3 pds; ts POORlY DeVelOPeD.

Head. LIgHT bROWN, WIDe, WITH PARAllel SIDeS; WIDTH: 0.70–0.90 MM, leNgTH: 0.60–0.80 MM; eNDOcARINA ReAcHeS 1/3 THe leNgTH OF FRONS. Des 4 VeRY SHORT ( FIg. 5g ). Fs 1 AND fs 3 VeRY SHORT, fs 4 MeDIUM lONg, fs 5 lONg. Les 1 SHORTeR THAN les 2. Ves 1-2 SHORT, POORlY DeVelOPeD. POSTePIcRANIAl AReA WITH 3 pes. STeMMATA DeVelOPeD. ANTeNNAl bASAl MeMbRANOUS ARTIcle WITH 5 bASIcONIc SeNSIllAe. LAbRUM ( FIg. 6g ) APPROXIMATelY 4.3 TIMeS AS WIDe AS lONg; ANTeRIORlY SlIgHTlY ROUNDeD; 3 PAIRS OF ams, DIFFeReNT IN leNgTH, MeDIAN PAIRS 3 TIMeS AS lONg AS lATeRAl SeTAe; 2 PAIRS OF als. LAbRAl RODS AlMOST PARAllel. ClYPeUS ( FIg. 6g ) 2.9 TIMeS AS WIDe AS lONg; ANTeRIOR AND lATeRAl MARgINS STRAIgHT; MeDIAN FURROW ReAcHeS 2/3 THe leNgTH OF clYPeUS; clss INVISIble. EPIPHARYNX ( FIg. 7g ) WITH 2 PAIRS OF als; 2 PAIRS OF ams AND 2 PAIRS OF mes. MANDIble WITH 1 SHARP ADDITIONAl TOOTH (clOSe TO APeX) AND ONe PROTUbeRANce IN THe MIDDle. MAXIllA ( FIg. 8g ) WITHOUT mbs; bOTH PAlPOMeReS eQUAl IN leNgTH, bASAl ONe DISTINcTlY WIDeR THAN DISTAl. PRAelAbIUM cORDIFORM , WITH 2 PAIRS OF ligs; bASAl PAlPOMeRe SHORTeR AND WIDeR THAN DISTAl; pslb 3 AlMOST HAlF THe leNgTH OF THe ReMAININg SeTAe.

Figures

FIGURES 5 (a – h). 5 — Mature larva, head. a—Andrion regensteinense, b—Charagmus gressorius, c— Sitona cylindricollis, d—S. hispidulus, e—S. lineatus, f—S. macularius, g—S. obsoletus, h—S. waterhousei. Setae: des — dorsoepicranial, fs — frontal, les — lateroepicranial, pes — postepicranial, ves — ventral.

FIGURES 6 (a – h). 6 — Larval mouthparts, labrum and clypeus. a—Andrion regensteinense, b—Charagmus gressorius, c— Sitona cylindricollis, d—S. hispidulus, e—S. lineatus, f—S. macularius, g—S. obsoletus, h—S. waterhousei. Setae: cls— clypeal, lrs— labral, clss — clypeal sensorium.

FIGURES 7 (a – h). 7 — Larval mouthparts, epipharynx. a—Andrion regensteinense, b—Charagmus gressorius, c— Sitona cylindricollis, d—S. hispidulus, e—S. lineatus, f—S. macularius, g—S. obsoletus, h—S. waterhousei. Setae: als— anterolateral, ams— anteromedial, mes— median.

FIGURES 8 (a – h). 8 — Larval mouthparts, maxillolabial complex, ventral aspect. a—Andrion regensteinense, b—Charagmus gressorius, c— Sitona cylindricollis, d—S. hispidulus, e—S. lineatus, f—S. macularius, g—S. obsoletus, h—S. waterhousei. Setae: dms— dorsomalar, ligs— ligular, mxps— maxillary palp, mbs— malar basiventral, pfs— palpiferal, plbs— prelabial, pslbspostlabial, stps— stipal, vms— ventromalar.

FIGURES 2 – 4 (a – d). 2 — Mature larva, chaetotaxy of thoracic segments, 3 — chaetotaxy of first abdominal segment, 4 — chaetotaxy of the 7 th — 10 th abdominal segments. a—Andrion regensteinense, b—Charagmus gressorius, c— Sitona cylindricollis, d—S. hispidulus. Setae: as — alar, ds — dorsal, eps — epipleural, eus — eusternal, lsts — laterosternal, pda — pedal, pds — postdorsal, prns — pronotal, prs — prodorsal, ps — pleural, sps — spiracular, sts — sternal, ts— terminal.