Mecinus pascuorum (Gyllenhal, 1813)

Gosik, Rafal, Skuhrovec, Jiri, Caldara, Roberto & Tosevski, Ivo, 2020, Immature stages of Palearctic Mecinus species (Coleoptera, Curculionidae, Curculioninae): morphological characters diagnostic at genus and species levels, ZooKeys 939, pp. 87-165 : 87

publication ID

https://dx.doi.org/10.3897/zookeys.939.50612

publication LSID

lsid:zoobank.org:pub:B2397011-4888-4712-880E-1069C943AD33

persistent identifier

https://treatment.plazi.org/id/D339190D-D364-53C5-AB6E-2B13D177D4A1

treatment provided by

ZooKeys by Pensoft

scientific name

Mecinus pascuorum (Gyllenhal, 1813)
status

 

Mecinus pascuorum (Gyllenhal, 1813) View in CoL

Material examined.

7 L3 larvae and 13 pupae, Serbia, Staničenje, 6.07.2017, 43°12.915'N, 22°30.495'E, 364 m., ex Plantago lanceolata , lgt. I. Toševski. Accession numbers of sequenced specimens MN992009 (larva), MN992010 (pupa).

Description of mature larva

(Figures 1A-D View Figure 1 , 2A-F View Figure 2 ). Measurements (in mm). Body length: 1.60-1.96. Body width (metathorax): 1.00-1.20. Head width: 0.36-0.40.

Body (Figure 1A-D View Figure 1 ) white, slender, curved. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, different in length, light yellow, on thoracic segments elongated or medium, on abdominal segments very short. Prothorax (Figure 1B View Figure 1 ) with eight prns of almost equal length, two ps and one eus. Meso- and metathorax (Figure 1B View Figure 1 ) with one medium prs, three medium pds, equal in length; one medium as, three medium ss, equal in length; one long eps, one long ps and one long eus. Pedal area with five long, equal in length pda. Abdominal segments I-VIII (Figure 1C, D View Figure 1 ) with one very short prs, four short pds (arranged along the posterior margin), two minute ss, two short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 1D View Figure 1 ) with three medium ds, all located close to the posterior margin, one short ps and two short sts. Each of anal lobes with two minute ts.

Head capsule (Figures 1A View Figure 1 , 2A-F View Figure 2 ) white, almost rounded. Des1-3, 5 long, des4 two times shorter than des1. Fs1 as long as des1, fs4, 5 elongated, equal in length. Les1 medium, les2 long; both ves very short, and two very short pes (Figure 2A View Figure 2 ). Antennae (Figure 2B View Figure 2 ) with conical, elongated sensorium (Se), four times as long as wide, and three sensilla basiconica. Clypeus (Figure 2C View Figure 2 ) trapezium-shaped, anterior margin slightly concave; cls2 short; clss close to cls2. Labrum (Figure 2C View Figure 2 ) narrow, trapezium-shaped, anterior margin distinctly sinuate; lrs1 long, lrs2 and lrs3 medium. Epipharynx (Figure 2D View Figure 2 ) with three finger-like als of almost equal length; two finger-like ams, different in length; two short finger-like mes; surface smooth; labral rods very short, rounded. Mandibles (Figure 2E View Figure 2 ) conical, rather wide, with divided apex (teeth of different lengths, curved); small protuberance in the middle of the cutting edge; with two medium mds capilliform, equal in length, placed transversely. Maxilla (Figure 2F View Figure 2 ) with one medium stps and two medium pfs; mbs short; mala with six long rod-like dms of almost equal size, five vms different in length. Maxillary palpi: basal palpomere distinctly wider and longer than distal. Prelabium (Figure 2F View Figure 2 ) cup-like with one long prms; ligula with two short ligs of different length; premental sclerite weakly developed, cup-like. Postlabium (Figure 2F View Figure 2 ) with short pms1, long pms2, and short pms3.

Description of pupa

(Figure 3A-C View Figure 3 ). Measurements (in mm). Head width: 0.32-0.40. Body width: 0.90-1.20. Body length: 1.52-2.10.

Body moderately stout, slightly curved, white. Rostrum moderately slender, medium long, about 2.5 times as long as wide, reaching mesocoxae. Antennae rather short. Pronotum 1.7 times as wide as long, with two, conical, protuberances apically (p-pr). Urogomorpi (ur) short, conical, with sclerotised apex (Figure 3A-C View Figure 3 ).

Chaetotaxy well visible, all setae (except those on rostrum and ventral part of abdomen) almost equal in length, medium. Head with one os. Rostrum with one minute rs (Figure 3A View Figure 3 ). Pronotum with two as placed beside protuberances, two ls, one ds and three pls. Dorsal parts of meso- and metathorax with two setae placed laterally. Abdominal segments I-VIII with three setae situated posteriorly, two elongated setae laterally and three short setae ventrally (median setae distinctly bigger than others). Abdominal segment IX with two micro-setae ventrally.

Biological notes.

This species lives on Plantago lanceolata L. In spring, the female lays one egg per developing pyxidium, and each larva consumes the contents of a pyxidium, usually two seeds, without causing externally visible modification. Pupation takes place within the same pyxidium. Adults emerge from the beginning of summer until September. They overwinter in the soil ( Hoffmann 1958; Scherf 1964; Dickason 1968; Nieminen and Vikberg 2015).

Remarks and comparative notes.

This species is one of the most common species in the genus, with a very large range of distribution: Europe, the Caucasian states, the Middle East, central Asia, and Algeria ( Caldara and Fogato 2013). It has been imported to North America, Australia and New Zealand ( O’Brien and Wibmer 1982; Debinski and Holt 2000) and recently collected in South Africa ( Caldara et al. 2009). Morphologically, this species is more closely related to other species of the group, i.e., M. latiusculus (Jacquelin du Val, 1855) and M. ictericus than to M. labilis studied herein, and this seems also to be corroborated by the preliminary molecular data (I. Toševski, unpublished data). However, the relationships among the immatures of these species are closer than their relationships with all the other species currently known.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Curculionidae

Genus

Mecinus