Mecinus circulatus group

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

Mecinus circulatus group

Differential diagnosis.

Larva. (1) body covered with asperities; (2) pedal lobes prominent well isolated; (3) abdominal segment X reduced to three anal lobes of unequal size; (4) thoracic spiracle bicameral; (5) abdominal setae very short, slightly growing from abdominal segment I to VIII; (6) abdominal segments I-VIII with three pds and two ss; (7) head brown, distinctly flattened laterally; (8) frontal suture poorly or well visible; (9) endocarina 1/2 of the frons; (10) des4 very short or short; (11) presence of fs1; (12) absence of fs2; (13) fs3 very short; (14) head with two stemmata; (15) presence of cls1; (16) labial palpi one-segmented; (17) premental sclerite cup-like; (18) surface of postlabium smooth.

Pupa. (1) body elongated or very elongated; (2) urogomphi slender, short or medium, reaching outline of the body, directed downward; (3) rostrum moderately elongated; (4) setae minute or medium; (5) head with one vs, one or two sos, one or two os; (6) rostrum with one sls and one rs; (7) pronotum with one or two as, without or with one ds, two sls, without or up to two ls, two or three pls; (8) meso- and metanotum with two setae; (9) abdominal segments I-VII with three or five setae dorsally.

Remarks and comparative notes.

The adults of this group are characterised by body elongate, subcylindrical, elytral integument reddish and black to completely black, protibiae with apical part of ventral surface distinctly directed outward. On the basis of these characters, this group might be related to M. collaris and especially to the M. simus group ( Caldara et al. 2013). The study of the immatures does not support this latter relationship. The immatures of this group lack autapomorphies. However, the larvae possess the unique combination of one palpomere + thoracic spiracle bicameral and abdominal spiracles unicameral, which do not share with the species of the M. simus group, M. pirazzolii , that we have studied.