Miarus ajugae (Herbst, 1795)

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 : 55-57

Miarus ajugae (Herbst, 1795) Figures 61, 62, 63-64, 65-66, 67, 68-70

Material examined.

26 L3 larvae: 9 exx., 12.07.2009, Bychawa ad Lublin, CE Poland, leg. E. Szwaj, det. J. Łętowski; 12 exx, ex galls on capsules of Adenophora liliifolia , 30.06.2017, Kaludjerske Bare, Mt. Tara, Central Serbia, leg. I. Toševski, det. R. Caldara; 5 exx, ex galls on capsules of Campanula bononiensis L., 14.07.2017, Zavojsko jezero, Pirot, east Serbia, leg. I. Toševski, all collected in association with adults, det. R. Caldara. Accession numbers of sequenced specimens: MH558548.

Description.

Measurements (in mm). Body length: 4.50-8.39 (mean 5.70). Body width (metathorax or abdominal segments I–II) up to 2.04. Head width: 0.68-0.83 (mean 0.70).

General. Body slender, C-curved, rounded in cross section (Fig. 61).

Colouration. Head dark brown to black (Fig. 61). All thoracic and abdominal segments yellowish with fine speculation, with clearly separated dark pigmented pedal areas (Fig. 61).

Vestiture. Setae on body very thin, piliform, distinctly different in length (minute to very short or long to very long).

Head capsule (Fig. 62). Head almost rounded. Frontal sutures narrow and loosened, but distinct. One stemma (st), in the form of a large pigmented spot. Des1-3 and des5 long; des4 very short (Fig. 62). Fs1 long; fs2 absent; fs3 short; fs4 and fs5 long (Fig. 62). Les1 and les2 as long as des5; both ves very short. Epicranial area with three very short pes and also three sensilla.

Antennae bearing one very long conical sensorium, and basal membranous article with three sensilla and one pore (Fig. 63).

Clypeus (Fig. 65) approximately 3.5 times as wide as long with two short, almost equal in length cls, and one sensillum between them; anterior margin sinuate.

Mouthparts. Labrum (Fig. 65) 1.6 times as wide as long, with three piliform lms, rather equal in length; lms1 located medially, lms2 located anteromedially, and lms3 located anterolaterally; all of them reaches labral margin. Epipharynx (Fig. 66) with three long finger-like als, all of identical in length; with two medium size ams; and two mes, first finger-like, second sharp and more slender; labral rods (lr) elongated, broad, slightly convergent posteriorly. Mandibles (Fig. 64) bifid; cutting edge with small blunt tooth; bearing with two setae in medium to long size, piliform, located apically and aligned longitudinally. Maxilla (Fig. 67) stipes with long stps and both pfs, very short to minute mbs, and one sensillum close to mbs; mala with six finger-like dms, different in length: first and second very long, forth to sixth medium size; 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 cuticular apical processes; length ratio of basal and distal palpomeres 1:0.9. Prelabium (Fig. 67) with one medium prms; ligula with two minute ligs; premental sclerite narrow, ring-shaped. Labial palpi with two palpomeres; length ratio of basal and distal palpomeres 1:0.7; each of the palpomeres with one sensillum, distal palpomere with cuticular apical processes. Postlabium (Fig. 67) with short pms1 located basally, long pms2 located medially and short pms3 located apically; membranous area without any asperities.

Thorax. Prothorax (Fig. 68) with ten prns (nine very long and one minute), small pigmented dorsal sclerite present with five long prns, this sclerite subdivided in two triangular plates medially; two long ps; and one short eus. Meso- and metathorax (Fig. 68) with one medium prs, three long pds; one very long as; two long and one minute ss; one long eps; one long ps; and one short eus. Chaetotaxy of metathorax (Fig. 68) almost identical to that of mesothorax. Each pedal area of the thoracic segments with six very long pda.

Abdomen. Abdominal segments I–VII (Figs 69-70) with one medium prs; two medium and one long to very long pds (order: medium, very long, medium); one very long and one minute ss; two long eps; one medium ps; one medium lsts; and two short eus. Abdominal segment VIII (Fig. 70) with one short prs; two short and one long pds (order: short, long, short); one long and one minute ss; two medium eps; one medium ps; one medium lsts; and two short eus. Abdominal segment IX (Fig. 70) with two relatively long and two short ds; two different in length ps; and two short sts. Abdominal segment X (Fig. 70) with one very short seta (ts).

Biology.

Miarus ajugae was collected on various species of the genus Campanula ( C. carpathica Jacq., C. glomerata L., C. latifolia L., C. macrorrhiza Gay ex DC, C. media L., C. patula L., C. persicifolia L., C. rapunculoides L., C. rapunculus L., C. rhomboidalis L., C. rotundifolia L., C. trachelium L.) and Phyteuma ( P. orbiculare L., P. spicatum L.) ( Caldara 2007). However, it was never reported previously to feed on Campanula bononiensis L. and Adenophora liliifolia (L.) A. DC. (see also Biology of C. graminis ).

Remarks.

This species with large Palaearctic distribution (from France and north-western Africa along all Europe to the Far East) is very closely related to M. campanulae , from which it differs mainly by the shape of the apex of the body of the penis ( Caldara 2007). Unfortunately, molecular studies on the fragment COI revealed poor differences between these two species ( Vahtera and Muona 2006; Hendrich et al. 2015, I. Toševski, unpublished data). Therefore, the consistent differences which we found in larval morphology between C. ajugae and C. campanulae are very important in order to confirm the validity of these two taxa at species level. Larvae of M. ajugae differ from all other species mainly by an epipharynx with two mes, first finger-like, second sharp and slender.