The morphology of the immature stages of Squamapion atomarium (Kirby, 1808) (Coleoptera, Brentidae) and notes on its life cycle.

Krzysztof Pawlęga,Tomasz Gosławski,Ewelina Szwaj,Jacek Łętowski

doi:10.3897/zookeys.892.36027

Abstract

The immature stages (egg, mature larva and pupa) of Squamapion atomarium (Kirby, 1808), as well as its development cycle and the phenology of its developmental stages, are described for the first time. The larva and pupa of S. atomarium have typical morphological features of the subfamily Apioninae. Morphological data on the immature stages were compared with the only fully described Squamapion species, S. elongatum (Germar, 1817). The larvae of the two species differ in body size and shape, head shape, setae length, the chaetotaxy of the mouthparts, and individual types of setae on the pronotum and thorax. In the case of the pupa, there are also differences in body size and in the type of setae and chaetotaxy of the head, pronotum, metanotum and abdomen.

Highlights

The genus Squamapion Bokor, 1923 belongs to the tribe Kalcapiini Alonso-Zarazaga, 1990 in the subfamily Apioninae Schönherr 1823 and family Brentidae Billberg 1820
S. atomarium feeds on the upper part of the stem of these plants, causing oval cecidia 2–4 mm long and 2 mm wide (Burakowski et al 1992)
Among species of the genus Squamapion, only S. elongatum (Germar, 1817) has previously been described, and the existing data on S. atomarium concern only its habitat and host plants, with an equal role ascribed to T. serpyllum and T. pulegioides (Burakowski et al 1992; Łętowski et al 2015)

Summary

Introduction

The genus Squamapion Bokor, 1923 belongs to the tribe Kalcapiini Alonso-Zarazaga, 1990 in the subfamily Apioninae Schönherr 1823 and family Brentidae Billberg 1820. The immature stages of representatives of this family have been described by Scherf (1964), Łętowski (1991), Marvaldi (1999, 2003), Gosik et al (2010), Wang et al (2013), Oberprieler et al (2014), and Łętowski et al (2015) This genus is known from the Palearctic and Ethiopian regions and is poorly represented in the Oriental region. There are 33 known species in the Palearctic region, 19 in Europe, and only 9 in Poland (Mokrzycki and Wanat 2005; Alonso-Zarazaga 2011; Alonso-Zarazaga et al 2017) These are herbivorous mono- or oligophagous species feeding on plants from the Lamiaceae family, with a preference for the genera Salvia L., Thymus L., Thymbra L., Mentha L., Origanum L., Prunella L. and Saccocalyx Coss. S. atomarium feeds on the upper part of the stem of these plants, causing oval cecidia 2–4 mm long and 2 mm wide (Burakowski et al 1992)

Material and methods

Results

Discussion