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 tr, Zootaxa 4108 (1), pp. 1-67: 32-33

publication ID

http://doi.org/10.11646/zootaxa.4108.1.1

publication LSID

lsid:zoobank.org:pub:B802F2B1-944E-4B84-A856-8091E60D88FC

persistent identifier

http://treatment.plazi.org/id/03EB857D-FFE6-AD2A-0592-FF2242DB173C

treatment provided by

Plazi

scientific name

Otiorhynchus
status

 

Otiorhynchus  (s. str.) meridionalis Gyllenhal, 1834 

Material examined: 2 larvae ( Fig. 212View FIGURES 211 – 219). JKI, Braunschweig, climate chamber, breeding with Forsythia  x intermedia Zabel and Ligustrum vulgare  flowerpots, 0 8.02 .2012, 1 ex., dto., 0 1.06 .2012, 1 ex.; details see below.

Remarks about breeding and development. A few larvae and pupae of Otiorhynchus meridionalis  were obtained from 1 breeding attempt in the climate chamber of the JKI in Braunschweig. On 24.06. 2011 10 males and 10 females were released on 2 big flowerpots with Forsythia  x intermedia. In October 1 plant had become dry and was replaced by Ligustrum ovalifolium  . In December many larvae died due to too strong watering. The remaining larvae were taken to the CURCI in Hannover for regular pupae control (description see Gosik & Sprick 2012 a). So for the description of the mature larva we had only 2 specimens at our disposal: one from 0 8.02. 2012 and a second that refused to pupate from 0 1.06. 2012. The adults used for breeding had been collected by Klaus Schrameyer in a front garden in the city of Heilbronn, and besides a record in Freiburg ( Maus 1998)—this is the only current locality of O. meridionalis  in Germany ( Schrameyer & Bernau 2011).

The life-cycle of Otiorhynchus meridionalis  is briefly outlined here; for more information see Bues et al. (1984). O. meridionalis  is widespread for example in natural habitats of South France. Its life-cycle was studied by Bues et al. (1984) due to observations of damage in strawberry plantations ( Audemard et al. 1981). In the field, egg deposition tends toward maximum activity from end of July until September. Larvae develop until spring of the following year and pupate from March to beginning of May. This corresponds well with our breeding data. O. meridionalis  did not show any diapause in the climate chamber, and larvae pupated due to the higher temperatures already in January and February. Around 3 weeks after pupation numbers of adults increase on the soil surface. In South France adults aestivate in July due to drought and high summer temperatures, apparently triggered by day length. It also of interest that a small proportion of adults overwinters and participates in egg-laying from May to mid-June. It is possible but unproven that the small proportion of recently emerged adults in the second half of the year is to trace back to the early egg-laying of overwintering adults. We observed overwintering of a more or less small proportion of adult specimens also in O. crataegi  in the field, but noticed egg deposition in the lab not until mid-June (main egg-laying period is as in O. meridionalis  in the second half of the year, in O. crataegi  starting at the end of July).

Description ( Figs. 78–88View FIGURES 78 – 83View FIGURES 84 – 88).

Coloration. Head dark yellow; all thoracic and abdominal segments yellowish.

Body elongated ( Fig. 78View FIGURES 78 – 83). Chaetotaxy: Setae different in length, filiform, fine, transparent. 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 medium long and 2 long); 1 long as; 1 long eps; and 1 long ps. Chaetotaxy of meso- and metathorax similar. Each pedal area of thoracic segments well isolated, with 4 pda, different in length. Each thoracic segment with 1 short eus ( Fig. 79View FIGURES 78 – 83). 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 minute sps [abd. seg. VIII only with 1 microseta]; 2 eps, different in length; 1 long and 1 short ps; 1 long lsts; and 2 eus ( Figs. 80, 82, 83View FIGURES 78 – 83). Abdominal segment IX with 3 ds, different in length; 1 long and 1 minute ps; and 2 sts, equal in length ( Figs. 81–83View FIGURES 78 – 83). Lateral lobes of abdominal segment X with 3 minute ts each.

Head subglobose (slightly narrowed) ( Fig. 84View FIGURES 84 – 88). 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 4 pairs of sensilla, frons with 3 pairs of sensilla. Stemmata (2 pairs) feebly visible. Antennal segment membranous, bearing 1 conical sensorium and 3–4 filiform sensilla. Clypeus 2.2 times as wide as long with 2 short cls, equal in length, placed posterolaterally ( Fig. 85View FIGURES 84 – 88). Labrum about 1.8 times as wide as long with 3 long, straight lms of different length, placed medially or mediolaterally; lms 1 somewhat shorter than other setae, all lms exceeding the outline of the labrum; the anterior margin of labrum rounded ( Fig. 85View FIGURES 84 – 88). Epipharynx with 3 finger-like als, different in length, 2 very short ams, different in length; and 2 very short mes; labral rods (lr) short, reniform, strong convergent ( Fig. 86View FIGURES 84 – 88). Mandible ( Fig. 87View FIGURES 84 – 88) bifid, teeth almost of equal height; with 2 mds, different in length; internal edge with a little triangular tooth. Maxilla ( Fig. 88View FIGURES 84 – 88) 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; basal one somewhat larger than distal; 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. 88View FIGURES 84 – 88), 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, 3 times as long as pms 1 and pms 3 ( Fig. 88View FIGURES 84 – 88).

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