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 : 37-42

Otiorhynchus (s. str.) tenebricosus (Herbst, 1784) complex: Otiorhynchus lugdunensis Boheman, 1843

Material examined: 17 larvae ( Fig. 215 ). JKI, Braunschweig, climate chamber, breeding with Euonymus fortunei , Ligustrum vulgare and Syringa vulgaris , 28.10.2011, 8 ex.; 16.11.2011, 1 ex.; 24.11.2011, 2 ex.; 0 5.01.2012, 1 ex.; 23.03.2012, 1 ex.; 16.08.2012, 1 ex.; 22.08.2012, 1 ex.; 26.06.2012, 3 ex.

Remarks about breeding and development. Larvae were received by one breeding attempt. 8 adults, 4 males and 4 females, were collected in Hannover-Linden in a park south of Leine river and placed in breeding cages with 4 Euonymus fortunei , 2 Ligustrum vulgare and 2 Syringa vulgaris flowerpots on 24.06.2011. At first checking on 21.09.2011 there were 31 small to medium-sized larvae, usually 1–4 per flowerpot, but in 1 Euonymus pot, there were 18. On 28.10.2011 around 49 larvae were counted, and some of them were already mature. In one of the Syringa flowerpots nearly all roots were eaten, and this plant was exchanged with Ligustrum vulgare . 12 larvae of different sizes were preserved in ethanol. On 16.11.2011 34 larvae were counted, and again a few were preserved. In several flowerpots the roots were eaten, 1 Euonymus plant had dried up and a few larvae were found dead or nearly dead. Hence the breeding plants of several flowerpots had to be renewed. On 0 5.01.2012 there were 5 flowerpots with Euonymus fortunei and 2 with Ligustrum vulgare , but only 11 larvae, 1 of them found dead in a very wet flowerpot (apparently drowned), a second still alive, but apparently suffering from too strong watering, the remaining in good condition and 10 of 11 mature. One flowerpot with 3 mature larvae was taken to Hannover for regular pupae control. From these larvae only 1 developed into the pupal stage, on 13.05.2012. A check in the climate chamber on 13.06.2012 revealed again 10 mature larvae (a few may have been overlooked before), of which 3 were taken to Hannover for pupae control, but did not pupate there. Also in Braunschweig only 1 more mature larva pupated on 27.09.2012, the remaining stayed for along time in the larval stage or died. The pupa was described in Gosik & Sprick (2013). In spite of the rapid development of the larva into the last larval instar, the receipt of the pupa was difficult and delayed for many months. The reasons are unknown. A possible reason is the absence of short-day conditions in the climate chamber.

Description ( Figs. 111–121 ).

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

Body elongated ( Fig. 111 ). Chaetotaxy: Setae different in length, 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. 112 ). 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, different in length; 1 long and 1 very short ps; 1 long lsts; and 2 eus ( Figs. 113, 115, 116 ). Abdominal segment IX with 3 ds, different in length; 1 long and 1 minute ps; and 2 sts, equal in length ( Fig. 114–116 ). Lateral lobes of abdominal segment X with 1 minute ts each.

Head subglobose (slightly narrowed) ( Fig. 117 ). 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; des2 and fs4 little shorter than other des and fs5. Postepicranial area with a group of 5 pairs and frons with 2 pairs of sensilla. Stemmata (1 pair) feebly visible. Antennal segment membranous, bearing 1 conical sensorium and 3–4 filiform sensilla. Clypeus 2.5 times as wide as long with 2 short cls, equal in length, placed posterolaterally ( Fig. 118 ). Labrum about 2 times as wide as long with 3 straight lms of different length, placed medially or mediolaterally; lms 1 some shorter than other setae, all lms exceeding the outline of the labrum; the anterior margin of labrum close to rounded ( Fig. 118 ). Epipharynx with 3 finger-like als, different in length; 2 ams, different in length; and 2 very short mes; labral rods (lr) short, reniform, strongly convergent ( Fig. 119 ). Mandible ( Fig. 120 ) bifid, teeth almost of equal height; with 2 mds, different in length; molar edge with a triangular tooth. Maxilla ( Fig. 121 ) with 1 very long stps and 2 very long pfs, placed ventrolaterally; 1 short mbs, situated ventrally. Mala with 6 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; basal palpomere with 2 sensilla, distal with 1 sensillum. Praelabium heart-shaped ( Fig. 121 ), with 2 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 5 times as long as pms 3 ( Fig. 121 ). Differential diagnosis. See “Key to larvae of selected Otiorhynchus species” and Tables 1, 2. For more comments about taxonomy of the three preceding taxa see: Introduction and Discussion.

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 111 – 116. Otiorhynchus lugdunensis; mature larva. 111 — habitus, lateral view, 112 — lateral view of thoracic segments, 113 — lateral view of abdominal segment I, 114 — lateral view of abdominal segments VIII – IX, 115 — ventral view of abdominal segments VIII – X, 116 — 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 117 – 121. Otiorhynchus lugdunensis; mature larva and mouthparts. 117 — dorsal view of head, 118 — labrum and clypeus, 119 — epipharynx, 120 — left mandible, 121 — 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.