Cleopomiarus graminis (Gyllenhal, 1813)

Skuhrovec, Jiri, Gosik, Rafal, Caldara, Roberto, Tosevski, Ivo, Letowski, Jacek & Szwaj, Ewelina, 2018, Morphological characters of immature stages of Palaearctic species of Cleopomiarus and Miarus and their systematic value in Mecinini (Coleoptera, Curculionidae, Curculioninae), ZooKeys 808, pp. 23-92 : 30-36

Cleopomiarus graminis (Gyllenhal, 1813) Figures 11, 12, 13-14, 15-16, 17, 18-20

Material examined.

11 L3 larvae: 6 exx., 18.07.2010, Wólka ad Lublin, CE Poland, leg. E. Szwaj, det. J. Łętowski; 5 exx., ex seed capsules of Campanula macrostachya Waldst. et Kit. ex Willd., Dobra, Iron Gate, east Serbia. 13.07.2015, leg. I. Toševski, all collected in association with adults, det. R. Caldara. Accession numbers of sequenced specimens: MH558545.

Description.

Measurements (in mm). Body length: 3.75-6.27 (mean 4.80). Body width (metathorax or abdominal segments I–II) up to 1.63. Head width: 0.65-0.78 (mean 0.71).

General. Body elongated, slender, curved, rounded in cross section (Fig. 11).

Colouration. Pale brown head (Fig. 11). All thoracic and abdominal segments from distinctly white to slightly yellow (Fig. 11).

Vestiture. Setae on body thin, slightly from orange to pale brown, distinctly different in length (minute to very short or long to very long). Cuticle distinctly asperate.

Head capsule (Fig. 12). Head oval, slightly flattened laterally. Frontal sutures narrow, but distinct. Anterior stemma (st), in the form of a large pigmented spot. Des1-3 and des5 long; des4 short to very short (Fig. 12). Fs1 long; fs2 absent; fs3 very short; fs4 long; and long fs5 (Fig. 12). Les1 and les2 as long as des5; both ves very short. Epicranial area with two sensilla and three minute pes in line with des2.

Antennae bearing one medium size conical sensorium, and basal membranous article with three sensilla different in length, two behind conical sensorium, and one ahead of it (Fig. 13).

Clypeus (Fig. 15) approximately 2.5-3 times as wide as long with two short cls, cls1 slightly shorter than cls2, and one sensillum; anterior margin sinuate.

Mouthparts. Labrum (Fig. 15) less than two times as wide as long, with three piliform lms, different in the length; lms1 located anteromedially, very close to margin of clypeus, lms2 located in the middle, and lms3 located anterolaterally; lms1 and lms2 of medium size, and lms3 distinctly shorter than the previous two; only lms2 distinctly reaches labral margin. Epipharynx (Fig. 16) with three long finger-like als, all of identical in length; with three ams in different length, ams1 and ams2 piliform of medium size, finger-like short ams3 and enlarged in middle, and also located more close to lr; without mes; labral rods (lr) distinct, elongated, oval. Mandibles (Fig. 14) bifid; bearing with two setae in medium size, piliform, and aligned longitudinally, mds1 located basally; mds2, located distinctly apically. Maxilla (Fig. 17) stipes with very long stps and pfs2, medium pfs1, very short to minute mbs, and sensillum close to mbs; mala with six medium sized finger-like dms; five vms, different in length, three setae medium size, and two setae very short. Maxillary palpi: basal palpomere with one short mxps and two sensilla; distal palpomere with some cuticular apical processes; length ratio of basal and distal palpomeres 1:0.8. Prelabium (Fig. 17) with one short prms; ligula with two very short to minute ligs; premental sclerite broad, ring-shaped. Labial palpi with two palpomeres; length ratio of basal and distal pal pomeres 1:0.8; each of the palpomeres with one sensillum, distal palpomere with cuticular apical processes. Postlabium (Fig. 17) with short pms1 located basally, very long pms2 located medially and short pms3 located apically; membranous area basolaterally distinctly asperate.

Thorax. Prothorax (Fig. 18) with nine very long and one very short to minute prns, small pigmented dorsal sclerite present with five long prns, this sclerite subdivided in two triangular plates medially; two very long to long ps; and one short eus. Meso- and metathorax (Fig. 18) with one long prs, three very long pds; one very long as; two very long and one very short to minute ss; one very long eps; one very long ps; and one short to very short eus. Each pedal area of the thoracic segments with 5-6 very long pda.

Abdomen. Abdominal segments I–VII (Figs 19-20) with one medium prs; one short and two very long to long pds (order: short, very long, long); one very long and one minute ss; two long eps; one very long ps; one long lsts; and two short to very short eus. Abdominal segment VIII (Fig. 20) with one very short to minute prs; one short and two long to relatively long pds (order: short, long, relatively long); one long and one minute ss; two very long eps; one long ps; one long lsts; and two short to very short eus. Abdominal segment IX (Fig. 20) with three relatively long and one short to very short ds; one relatively long and sometimes one minute ps; and one relatively long to short and one short to very short sts. Abdominal segment X (Fig. 20) with one very short seta (ts).

Biology.

Larvae were collected while feeding on the seeds of several species of Campanula , mainly C. glomerata , C. persicifolia , and C. rotundifolia L. ( Hustache 1932; Hoffmann 1958; Smreczyński 1976; Lohse and Tischler 1983; Caldara and Legalov 2016) without producing galls. The species was not previously reported on Campanula macrostachya Waldst. and Kit. ex Willd., a taxon distributed from Ukraine along the Balkans until Anatolia. Pupae, as well as immatures of M. ajugae , were also collected on Adenophora liliifolia (L.) A. DC, although in another Serbian locality (see below). This genus, however, is very closely related to Campanula ( Cano-Maqueda and Talavera 2011).

Remarks.

This is a very common and variable species with a wide European and Asian distribution from the Iberian Peninsula to eastern China ( Caldara and Legalov 2016; Jiang et al. 2018). The two most variable characters in adults are the colour of the dorsal vestiture, which varies from whitish grey to light brown, and the density of the elytral scales, sometimes completely covering the integument. The rostrum varies somewhat in length and curvature, especially in the female. Cleopomiarus graminis is very closely related to C. longirostris as demonstrated by our data on the molecular fragment COI (I Toševski, unpublished data). Therefore, the differences between these two taxa found in the study of the immature stages, especially in the larvae - antennae with a very long conical sensorium and three sensilla (Figs 13, 33), dorsal setae (except des4) long (Figs 12, 32), prothorax with nine very long and one very short to minute prns (Figs 18, 38) - are very important in order to confirm the specific rank of both taxa. On the other hand, the larva of C. longirostris is distinctly longer than the larva of C. graminis . With regard to the differences from C. distinctus , another widespread sympatric species sometimes confused with C. graminis , see the Remarks for the former taxon.