Immatures of Palaearctic species of the weevil genus Tychius (Coleoptera, Curculionidae): new descriptions and new bionomic data with an evaluation of their value in a phylogenetic reconstruction of the genus Author Skuhrovec, Jiří Author Gosik, Rafał Author Caldara, Roberto text Zootaxa 2014 2014-07-23 3839 1 1 83 journal article 5426 10.11646/zootaxa.3839.1.1 6d32f9c2-3094-425b-bb7e-9c6e0517d4fd 1175-5326 4927721 AA7FEED5-5C1F-48D0-A172-5C25C4001DF3 Tychius (s. str.) curtirostris Desbrochers, 1873 Caldara 1990: 192 . Material examined. 33 larvae from pods of Trifolium glomeratum L. collected 5.vii.1982 at Levanto , La Spezia province , Liguria (northern Italy ), leg. R . Caldara , and 7 pupae reared from larvae collected contemporaneously together with the others, all determined by association with reared adults. Differential diagnosis. See Tables 2 and 3 . Description of mature larva. COLORATION. Head yellow. All thoracic and abdominal segments light yellow. HEAD CAPSULE AND MOUTH PARTS. Head width: 0.28–0.35 mm (see Table. 1 ). Endocarinal line present, exceeding middle of frons. Des 1 located very near frontal suture; des 2 absent; des 3 located along frontal suture; des 4 located anterolaterally; des 5 located laterally; des 4 5 times shorter than des 1 , des 3 and des 5 ( Fig. 151 ). Fs 1 and fs 2 absent; fs 3 very short, located medially; fs 4 located anteromedially (along epistoma); fs 5 located anterolaterally (along epistoma), 6 times longer than fs 3 ( Fig. 151 ). Les distinctly shorter than des 3 . Ves very short. Post-epicranial area with group of 3 minute pes . Antennal segment membranous, bearing conical sensorium and 2 very short, conical, sensilla ( Fig. 154 ). Labrum ( Fig. 155 ) approximately 3.1 times as wide as long; lms 1 slightly longer than equal in length lms 2 and lms 3 ; anterior margin rounded. Clypeus ( Fig. 155 ) 3.25 times as wide as long; with 2 pairs of very short cls of same length, and 1 sensillum, all posterolaterally; anterior margin almost straight. Epipharynx ( Fig. 156 ) with 2 pairs of als , different in length; with 2 pairs of short ams ; with 2 relatively short finger-like and 1 short mes ; labral rods short, kidney-shaped, slightly converging posteriorly. Mandibles ( Fig. 153 ) with 2 short mds , almost of equal length. Maxilla ( Fig. 152 ): stipes with 1 stps , 2 pfs of different length, and 1 mbs , distinctly shorter than pfs ; mala with 4 straight dms , different in length; with 4 vms , moderately long and almost of equal length. Maxillary palpi: length ratio of basal and distal palpomeres 1:1.4; basal palpomera with 1 short mpxs ; distal palpomera with group of some conical, cuticular apical processes. Prementum ( Fig. 152 ) heart-shaped, with 1 prms ; margin of ligula slightly rounded; ligula with 2 ligs ; premental sclerite distinct. Postmentum ( Fig. 152 ) with 3 pairs of pms , different in length. THORAX AND ABDOMEN. Body length 1.6–2.4 mm (see Table. 1 ), moderately elongate. Abdominal segments I- III slightly smaller than abdominal segments IV–VI ( Fig. 157 ). Spiracles on abdomen in anteromedian parts of segments (abdominal segments I–VIII). Chaetotaxy of body rather reduced. Setae moderately short or very short and light yellow. Thorax. Prothorax ( Fig. 158 ) with 7 prn , 6 macro- and 1 microsetae; 2 moderately long ps of same length; 1 eus . Mesothorax ( Fig. 158 ) with 1 prs ; 3 pds , different in length; alar area with 1 very short as ; 1 very short ss ; 1 eps ; 1 ps ; and 1 short eus . Chaetotaxy of metathorax almost identical to that of mesothorax, on metathorax only 2 pds . Each pedal area of thoracic segments well-separated and with 3 pda , equal in length (moderately long). Abdomen. Abdominal segments I–VII ( Fig. 159 ) with 1 prs ; 2 pds of different length; 2 very short ss ; 2 eps of different length; 2 ps of different length; 1 lsts ; and 2 short eus . Abdominal segment VIII ( Fig. 160 ) with 2 pds ; 1 very short ss ; 2 eps of different length; 2 ps of different length; 1 lsts ; 2 short eus . Abdominal segment IX ( Fig. 160 ) with 1 ds ; 2 very short ps ; and 1 sts . Anal lobes on abdominal segment X ( Fig. 160 ) with 1 very short, feebly visible seta. Description of pupa. COLORATION. Body whitish yellow. MORPHOLOGY ( Figs. 161–163 ). Body length 1.7–2.2 mm ; widest part 0.7–1.0 mm (see Table. 1 ). Body elongate, slender. Rostrum long, approximately 4.5 times as long as wide, reaching mesocoxae. Pronotum 1.4 times as wide as long. CHAETOTAXY ( Figs. 161–163 ). Setae distinct, long or moderately long, unequal in length, light brown; on pronotum and head placed on small protuberances. Head capsule including 1 vs , 1 os , and 1 pas . Rostrum with 1 rs located medially. Vs and os as long as setae on pronotum, distinctly longer than pas and rs . Pronotum with 2 as , 2 ls , 1 ds , and 1 pls ; ds distinctly smaller than other setae on pronotum. Dorsal parts of meso- and metathorax with 1 seta. Each apex of femora with 1 fes . Setae on abdominal segments I–VIII placed medially and laterally; all abdominal setae located on small, conical protuberances. Pseudocerci short, slightly curved inside. Biological observations. Pupae were observed 7 days after the entrance of larvae into the soil. The duration of the pupal stage was 7 days. Adults emerged at the surface 3 days later. Remarks. Tychius curtirostris is a common species with a circummediterranean distribution and is easily confused with T. pusillus ( Caldara 1975 , 1990 ). In the same field, where T. curtirostris was collected, T. tibialis was collected also, but living on T. incarnatum L.