Mecinus pirazzolii (Stierlin, 1867)

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/B5BBE85B-3B1F-56AD-9F0B-995DDC6DDC31

treatment provided by

ZooKeys by Pensoft

scientific name

Mecinus pirazzolii (Stierlin, 1867)
status

 

Mecinus pirazzolii (Stierlin, 1867)

Material examined.

20 L3 larvae and 10 pupae, Serbia, Veliko Gradište, 14.07.2017, 44°45.039'N, 21°31.426'E, 86 m., ex Plantago arenaria , lgt. I. Toševski. Accession numbers of sequenced specimens MN992011 (larva), MN992012 (pupa).

Description of mature larva

(Figures 7A-D View Figure 7 , 8A-F View Figure 8 ). Measurements (in mm). Body length: 1.40-2.00. Body width (metathorax): 0.73-1.00. Head width: 0.36-0.40.

Body (Figure 7A-D View Figure 7 ) white, slender, curved. Chaetotaxy of thoracic segments relatively well developed, setae capilliform, different in length, light yellow; on abdominal segments almost invisible (except dorsal parts of abdominal segments IX and X). Prothorax (Figure 7B View Figure 7 ) with eight prns of unequal length (seven relatively long and one medium), two relatively long ps and one short eus. Meso- and metathorax (Figure 7B View Figure 7 ) with one medium prs, two long pds, equal in length, one long as, three ss different in length (two relatively long, one short), one long eps, one long ps and one short eus. Pedal area with five long pda, equal in length. Abdominal segments I-VIII (Figure 7C, D View Figure 7 ) with one very short prs, three short pds (on segment VIII medium, equal in length), arranged along posterior margin, two minute ss, one short eps, one short ps, one short lsts and two short eus. Abdominal segment IX (Figure 7D View Figure 7 ) with three medium ds, all located close to posterior margin, one short ps and two short sts. Each of anal lobes with one minute seta.

Head capsule (Figures 7A View Figure 7 , 8A-C View Figure 8 ) light white, almost rounded. Des1,3,5 long; des2 two times shorter than des1; des4 three times shorter than des1. Fs4,5 equal in length, almost as long as des1. Les1 medium, les2 long; one very short ves, and one pes (Figure 8A View Figure 8 ). Antennae (Figure 8B View Figure 8 ) with conical, elongated sensorium (Se), four times as long as wide, and three sensilla basiconica. Clypeus (Figure 8C View Figure 8 ) trapezium-shaped, anterior margin slightly concave; cls2 short; clss situated close to cls2. Labrum (Figure 8C View Figure 8 ) narrow, trapezium-shaped, anterior margin slightly sinuate; lrs1 long, lrs2 medium lrs3 short. Epipharynx (Figure 8D View Figure 8 ) with three finger-like als of almost equal length; two medium finger-like ams; two short finger-like mes; surface smooth; labral rods very short, rounded. Mandibles (Figure 8E View Figure 8 ) conical, rather wide, with a small protuberance in the middle of the cutting edge; both mds capilliform, medium, equal in length, placed transversely. Maxilla (Figure 8F View Figure 8 ) with one stps and two pfs of equal length; 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 8F View Figure 8 ) cup-like with one long prms; ligula with two short ligs; premental sclerite clearly visible, cup-shaped, posterior extension with acute apex. Postlabium (Figure 8F View Figure 8 ) with medium pms1, medium pms2, and short pms3.

Description of pupa

(Figure 9A-C View Figure 9 ). Measurements (in mm). Head width: 0.33-0.40. Body width: 0.93-1.16. Body length: 1.63-2.10.

Body stout, slightly curved, white. Rostrum slender, very short, tapering to its top. Antennae moderately elongated. Pronotum 2.0 times as wide as long. Urogomorpi (ur) very short, conical, not reaching outline of the body (Figure 9A-C View Figure 9 ).

Chaetotaxy almost invisible, all setae minute, possible to observation only under higher magnification. Head with one os. Rostrum with one rs placed medially (Figure 9B View Figure 9 ). Pronotum with two as, one ls, one ds and three pls. Dorsal parts of meso- and metathorax with two setae placed laterally. Dorsal parts of abdominal segments I-VIII with three setae situated posterolaterally and one seta laterally. Abdominal segment IX without setae.

Biological notes.

This species is associated with the annual plant Plantago arenaria Waldst. & Kit. The adult aggregation on plants is followed by the appearance of flowering stems with spikes in late spring. The females lay one egg onto the base of the pistil or the initialised seed. The act of oviposition is followed by proliferative growth of the ovarian tissue in the form of gall but without changes in the external morphology of the pyxidium. During development, the larvae consume all the tissue inside the pyxidium, leaving only the fruit shell intact. The larvae pupate inside the fruit shell, from which adults emerge after being completely sclerotised. Overwintering takes place in the soil litter near the host plant (I. Toševski, pers. obs.). Sympatric occurrence with M. ictericus is common ( Caldara and Fogato 2013).

Remarks and comparative notes.

This species is distributed in eastern Central Europe, southeastern Europe and Turkey. In our keys, this species is closer to the species of the M. pascuorum group than to others, as already discussed in the Remarks for the group.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Curculionidae

Genus

Mecinus