Otiorhynchus

Rafał Gosik, Peter Sprick, Jiří Skuhrovec, Magdalena Deruś & Martin Hommes, 2016, Morphology and identification of the mature larvae of several species of the genus Otiorhynchus (Coleoptera, Curculionidae, Entiminae) from Central Europe with an update of the life history traits, Zootaxa 4108 (1), pp. 1-67 : 36-37

Otiorhynchus (s. str.) tenebricosus (Herbst, 1784) complex: Otiorhynchus fuscipes (Olivier, 1807)

Material examined: 4 larvae ( Fig. 214 ). Ith Mountains, southwest of Hannover, in the district of Hameln, Niedersachsen, 350–400 m, 13.10.2011, 2 ex.; dto., 0 1.09.2012, 1 ex.; dto., 26.03.2012, 1 ex.

Remarks about sampling and development. All larvae were received from field-sampling in a beech forest on limestone, at about 350–400 m above sea level in the submontane climate zone. The larvae were found between the roots of young Fraxinus excelsior L. plants, growing intermixed with Allium ursinum L., which can be recognized by their characteristic subterranean overwintering organs, the longitudinal bulbs. As we know there are no data on the life-cycle of this taxon including larval development.

Description ( Figs. 100–110 ).

Coloration. Head dark brown; all thoracic and abdominal segments from dark yellow to brownish; cuticle almost smooth.

Body moderately elongated ( Fig. 100 ). Chaetotaxy: Setae different in length, relatively long, filiform, brownish. Thorax. Prothorax with 4 long and 5 medium long to short prns; and 2 ps, different in length. Mesothorax with 1 medium long prs; 4 pds (ordered: 2 short and 2 long); 1 long and 1 very short as; 1 long eps; and 1 long ps. Chaetotaxy of meso- and metathorax similar. Each pedal area of thoracic segments well isolated, with 5 pda, different in length. Each thoracic segment with 1 short eus ( Fig. 101 ). Abdomen. Abdominal segments I–VIII with 1 short prs; 5 pds (ordered: 2 short, 1 long, 1 short and 1 long); 1 long and 1 very short sps [abd. seg. VIII only with 1 very short sps]; 2 eps almost equal in length; 1 long and 1 short ps; 1 long lsts; and 2 eus ( Figs. 102, 104, 105 ). Abdominal segment IX with 3 ds, different in length; 1 long and 1 very short ps; and 2 sts, equal in length ( Figs. 103–105 ). Lateral lobes of abdominal segment X with 2–3 minute ts each.

Head subglobose (slightly narrowed) ( Fig. 106 ). Head capsule with 4 long des, des 1 and des 2 placed on central part of epicranium, des 3 located on frontal suture, des 5 located anterolaterally; 2 long fs, fs 4 placed anteromedially, fs 5 located near to antenna; 2 long les; and 1 very short ves. Postepicranial area with a group of 5 pairs of sensilla, frons with 2 pairs of sensilla. Stemmata (2 pairs) feebly visible. Antennal segment membranous, bearing 1 conical sensorium and 3–4 filiform sensilla. Clypeus 2.1 times as wide as long with 2 cls, equal in length, placed posterolaterally ( Fig. 107 ). Labrum about 1.6 times as wide as long with 3 straight lms of different length, placed medially or mediolaterally; lms 1 shorter than other setae, all lms exceeding the outline of the labrum; the anterior margin of labrum almost rounded ( Fig. 107 ). Epipharynx with 3 finger-like als, different in length; 2 ams, different in length; and 2 very short mes; labral rods (lr) short, reniform, strong convergent ( Fig. 108 ). Mandible ( Fig. 109 ) bifid, teeth almost of equal height; with 1 short and 1 long mds; internal edge with a triangular tooth. Maxilla ( Fig. 110 ) with 1 very long stps and 2 very long pfs, placed ventrolaterally; 1 very short mbs, situated ventrally. Mala with 7 dms, different in length and 4 straight vms, different in length. Maxillary palpi with two palpomeres of almost equal length; basal palpomere with 1 mxps; distal palpomere with a group of 6 conical, cuticular processes apically; each palpomere with a sensillum. Praelabium heart-shaped ( Fig. 110 ), with 2 very short ligs and 1 long prms. Labial palpi with two palpomeres, relatively elongated; both palpomeres almost equal in length; praemental sclerite wide, well visible. Postlabium with 3 pms, different in length; pms 2 very long, 2 times as long as pms 1 and 3 times as long as pms 3 ( Fig. 110 ).

Differential diagnosis. See “Key to larvae of selected Otiorhynchus species” and Tables 1, 2.

Figures

FIGURES 211 – 219. Mature larva, lateral view. 211 — O. aurifer, 212 — O. meridionalis, 213 — O. clavipes (= O. tenebricosus), 214 — O. fuscipes (= O. tenebricosus), 215 — O. lugdunensis, 216 — O. salicicola, 217 — O. ovatus, 218 — O. crataegi, 219 — O. rugosostriatus. (Photos by R. Gosik).

FIGURES 100 – 105. Otiorhynchus fuscipes (= O. tenebricosus); mature larva. 100 — habitus, lateral view, 101 — lateral view of thoracic segments, 102 — lateral view of abdominal segment I, 103 — lateral view of abdominal segments VIII – IX, 104 — ventral view of abdominal segments VIII – X, 105 — dorsal view of abdominal segments VIII – X. Abbreviations: Ab. — abdominal segment, Th. — thoracic s., I – X—number of segments, prns — pronotal seta (e), prs — prodorsal s., pds — postdorsal s., pda — pedal s., as — alar s., lsts — laterosternal s., eus — eusternal s., ps — pleural s., sps — spiracular s., sts — sternal s., ds — dorsal s., ts — terminal s.

FIGURES 106 – 110. Otiorhynchus fuscipes (= O. tenebricosus); mature larva and mouthparts. 106 — dorsal view of head, 107 — labrum and clypeus, 108 — epipharynx, 109 — left mandible, 110 — maxillo-labial complex. Abbreviations: des — dorsoepicranial seta (e), fs — frontal s., les — lateroepicranial s., ves — ventroepicranial s., at—antenna, st—stemmata, cls — clypeal s., lms — labral s., ams — anteromedial s., als — anterolateral s., mes — medial s., lr—labral rods, mds — mandible dorsal s., dms — dorsal malae s., vms — ventral malae s., mxps — maxillary palps s., pfs — palpiferal s., stps — stipal s., mbs — mandible basiventral s., prms — prelabial s., pms — postlabial s., ligs — ligular s.