Larinus (Phyllonomeus) turbinatus Gyllenhal, 1836

Gosik, Rafał & Skuhrovec, Jiří, 2011, Descriptions of mature larvae and pupae of the genus Larinus (Coleoptera: Curculionidae, Lixinae), Zootaxa 3019, pp. 1-25 : 19-23

Larinus (Phyllonomeus) turbinatus Gyllenhal, 1836

Material. (5 mature larvae, 1 pupa), collected in the flower heads of melancholy thistle ( Cirsium heterophyllum L.) growing on wet meadows: CZECH REPUBLIC bor., Liberec env., Janov nad Nisou—Hrabĕtice (5257), N50°46'40.5'', E 15°41'8.09'', 740 m a.s.l., 8.vii.2008, J. Skuhrovec leg.

Differential diagnosis. Mature larva. Endocarina present (x L. pollinis ) ( Figs. 43, 44 ). Des 4 close to des 5 (x L. obtusus , L. pollinis L. sturnus ) ( Figs. 43, 44 ). Less than 15 setae on pronotum (x L. pollinis ) ( Fig. 51 ). Spiracular area in meso- and metathoax with four setae (x L. obtusus , L. pollinis , L. sturnus ) ( Fig. 51 ). Abdominal segment I– VII with 1 prs, 7 pds, 2 dpls and 2 vpls (x L. obtusus , L. pollinis ) ( Fig. 52 ). Setae on thorax and abdomen relatively short ( Figs. 51, 52 ) (x L. obtusus , L. pollinis , L. sturnus ). Pupa. Sas on head, no protuberance with a shape such as horns (x L. sturnus ) ( Figs. 54, 55 ). Less than 15 setae on pronotum (x L. pollinis ) ( Fig. 55 ). Seta 1 on abdominal segment I. in line with the remaining 7 setae, all close to the posterior margin (x L. obtusus , L. pollinis , L. sturnus ) ( Fig. 55 ). Pc distinct and long (x L. obtusus , L. pollinis ) ( Figs. 54–56 ).

Description of mature larva. COLORATION. Head light brown. All thoracic and abdominal segments white. Cuticle minutely spiculated.

HEAD CAPSULE AND MOUTH PARTS. Head width: 1.5–1.7 mm (mean 1.6 mm), suboval, slightly oblate laterally, endocarinal line present, reaches middle of the frons. Des 1 and des 2 located in the central part of the epicranium, des3, des 4 and des 5 located near the frontal suture, of equal length ( Figs. 43, 44 ). Fs 1, fs 2 placed along frontal suture, fs 3, fs 4 and fs 5 located close to epistoma, of equal length ( Figs. 43, 44 ). Les 1, 2 and ves 1, 2 slightly shorter than des. Epicranial area with group of 3 pores; one located near des 1, with the next two pores placed laterally. Antenna with sensorium conical triangular, relatively long and slender, located medially; basal membranous article with 6 triangular sensillae ( Fig. 45 ).

Labrum ( Fig. 46 —left side) approx 1.7 times as wide as long with 3 pairs of long, bacilliform lrms of different length; lrms 2 slightly longer than lrms 1 and lrms 3; all lrms distinctly placed on protuberances; anterior margin double sinuate. Clypeus ( Fig. 46 —left side) 3 times as wide as long with 2 pairs of long, hairform cls, unequal in length, located posterolaterally; anterior margin slightly rounded to the inside. Epipharynx ( Fig. 46 —right side) with 5 pairs of blunt als of different length; anteriorly, 2 pairs of ams, with ams 1 distinctly longer than ams 2; labral rods (lr) very short, converging posteriorly. Mandibles ( Fig. 47 ) relatively broad, highly truncated; short, hairform mds 1, 2 almost of equal length. Maxilla ( Fig. 48 ) stipes with 1 stps and 2 pfs, equal in length; mala with 9 bacilliform dms, different in length; vms 1-2 short, almost equal in length; vms distinctly shorter than dms. Maxillary palpi with two palpomeres; basal palpomere with 1 mxps and two pores; length ratio of basal and distal palpomeres: 1:0.7; distal palpomere with group of 6 conical, cuticular apical processes and one pore. Praelabium ( Fig. 49 ) heartshaped, with 1 plbs; margin of ligula sinuate and 3 micro ligs of different length; premental sclerite well visible. Labial palpi with two palpomeres; length ratio of basal and distal palpomeres 1:0.8; distal palpomere with 5 conical cuticular apical processes; basal palpomere with 1 dorsal pore. Postlabium ( Fig. 49 ) with 3 pslbs of different length, one seta located medially, remaining two setae laterally.

THORAX AND ABDOMEN. Body length: 8.0–12.0 mm (mean 10.5 mm), relatively elongated, slightly curved ( Fig. 50 ). The widest place in the body (metathorax) up to 3.1 mm. Abdominal segments I–IV almost equal in length, slightly smaller than abdominal segments V–VI, with the next abdominal segment decreasing gradually to the terminal parts of the body. Spiracles on the abdomen in the lateral regions of abdominal segments I–VIII ( Fig. 52 ).

Chaetotaxy of the body reduced, poorly distinguished. Setae thin, short, light yellow. Thorax. Prothorax ( Fig. 51 ) with 14 prns almost in equal length, 2 vpls and 1 msts. Mesothorax ( Fig. 51 ) with 1 prs, 5 pds, 1 as, 4 ss different in length, 1 dpls, 2 vpls and 1 msts.Chaetotaxy of metathorax ( Fig. 51 ) similar to mesothoracal. Each pedal area of thoracic segments well separated, with 8 pda of different lengths. Abdomen. Abdominal segments I–VII ( Fig. 52 ) with 1 prs, 7 pds, 1 dls, 1 ss in the spiracular area, 2 dpls, 2 vpls, 1 lsts and 2 short msts. Abdominal segment VIII with 1 prs and 7 pds of different length, 2 dls, 1 ss, 1 dpls, 1 vpls, 1 lsts and 2 short msts. Abdominal segment IX ( Fig. 53 ) with 5 ds, 2 ls and 2 sts ( Fig. 53 ). Each anal lobe on abdominal segment X ( Fig. 53 ) with 1 micro-seta.

Description of pupa. COLORATION. Body white or yellowish; cuticle smooth.

MORPHOLOGY ( Figs. 54–56 ). Body length 7.8 mm, width in the widest region (between end of mesofemurs): 3.9 mm. Body elongated, slender, slightly curved. Rostrum medium long, approx. 1.7 times as long as wide, reaching up to the mesocoxae. Antennae long and slender. Pronotum almost 2.0 times as wide as long. Abdominal segments I–IV of equal length; following abdominal segments diminish gradually to the end of the body. Abdominal segments VII–IX distinctly smaller than other abdominal segments.

CHAETOTAXY ( Figs. 54–56 ). Setae distinct, medium long, light yellow, unequal in length, placed on small protuberances on the pronotum. Head capsule includes 1 vs, 2 sos, 1 os and 4 pas. Rostrum with 4 rs, 1 pair placed medially, remaining 3 pairs located on the anterior margin of rostrum; and a pair of mts. Setae on head capsule and rostrum straight, almost of equal length, slightly shorter than those on thoracic and abdominal segments. Pronotum with 1 sas placed on small, conical, protuberance; 6 ls; 2 ds; 2 sls and 4 pls. Dorsal parts of mesothorax with 6 pairs of setae, 1 pair placed posteromedially and 5 pairs medio-laterally in a group. Chaetotaxy of metathorax similar to mesothoracal. Each apex of the femora with groups of 3 fes. Dorsal parts of abdominal segments I–VIII with 1 pair of setae placed posterolaterally and 8 pairs distributed along its anterior margin. Setae on abdominal segments VI– VIII placed on conical protuberances. Abdominal segments I–VIII with groups of 4 lateral setae and 3 pairs of short ventral setae in regular lines. Abdominal segment IX with 4 pairs of ventral micro-setae and 3 pairs of short, thin dorsal setae. Pseudocerci elongated, slightly curved to inside.

Remarks. Scherf (1964) mentioned this species in his book, but he recorded only descriptions of its eggs, larval biology and parasitoids.

Figures

FIGURES 43 – 49. Larinus turbinatus mature larva head, antenna and mouth parts: 43 — dorsal view, 44 — lateral view (des — dorsal epicranial s., fs — frontal s., les — lateral epicranial s., ves—ventral epicranial s., at — antenna, st — stemma), 45 — antenna, 46 (left side) — labrum and clypeus (cls — clypeal s., lrms — labral s.), 46 (right side) epipharynx (ams — anteromedial s., als — anterolateral s., lr — labral rods), 47 — right mandible (mds — mandible dorsal s.), 48 — left maxilla, dorsal view (dms — dorsally malae s., vms — ventrally malae s., mpxs — maxillary palps s., pfs — palpiferal s., stps — stipal s.), 49 — praelabium and postlabium, ventral aspect (plbs — prelabial s., pslbs — postlabial s., ligs — ligular s.).

FIGURES 50 – 53. Larinus turbinatus mature larva habitus: 50 — lateral view, 51 — lateral view of thoracic segments, 52 — lateral view of first abdominal segment, 53 — lateral view of abdominal segments VIII – X (prns — pronotal s., dpls — dorsopleural s., vpls — ventropleural s., prs — prodorsal s., pds — postdorsal s., pda — pedal s., as — alar s., ss — spiracular s., dls — dorsolateral s., lsts — laterosternal s., msts — mesosternal s., sts — sternal s., ls — lateral s., ds — dorsal s.).

FIGURES 54 – 56. Larinus turbinatus pupa habitus: 54 — ventral view, 55 — dorsal view, 56 — lateral view (pc — pseudocerci, sas — super apical s., ls — lateral s., sls — super lateral s., ds — discal s., pls — posterolateral s., vs — vertical s., sos — super orbital s., os — orbital s., pas—postantennal s., rs — rostral s., mts — mandibular thecae s., fes — femoral s.).