Cetoniinae

Vondráček, Dominik, Hadjiconstantis, Michael & Šípek, Petr, 2018, Immature stages of the genus Oxythyrea (Coleoptera: Scarabaeidae: Cetoniinae) with a key to third instar larvae, and notes on the biology of the genus, Zootaxa 4486 (4), pp. 401-434 : 422-423

Key to the larval instars of Cetoniinae

Note: We provided this key to be sure, that readers of this work will be able to distinguish third instar larvae (L3) of Cetoniinae from other instars (L1, L2), because L3 of smaller species (e.g. Oxythyrea ) can be the same size as L1 and L2 of some bigger species (e.g. Protaetia sp. Burmeister, 1842). Almost all descriptions of Scarabaeidae larvae are based on the third instar larva, but some of key morphological structures (e.g. raster) are not fully developed only in early instars (e.g. Šípek et al. 2012b). Therefore, the correct identification of larval instar is necessary. The characteristic given here are mostly based on unpublished material collected by the authors (pers. observation), as published data on the early stages larvae (L1, L2) of the Cetoniinae is missing ( Šípek et al. 2012b).

1 Respiratory plate of (thoracic) spiracle oval or round, bullar opening narrow and tiny, respiratory plate covering almost entire area of the spiracle ( Fig. 13 A )................................................................ first instar larva

- Thoracic spiracle with well-defined c-shaped respiratory plate and well-developed bulla............................. 2

2 Thoracic spiracle with bulla without ecdysial scar ( Fig. 13B ), if ecdysial scar present ( Fig. 13C ) then pali slender, distinctly shorter and less sclerotized when compared to tegillar setae ( Fig. 13I ; compare with Fig. 13J ). Not aplicable for species without distinctly developed raster (rows of pali), i. e. in Europe for larvae of the genus Osmoderma LePeletier & Audinet-Serville, 1828 ..................................................................................... 2nd instar larva

- Thoracic spiracle with well-developed bulla and well-developed ecdysial scar ( Fig. 13C ), pali of raster normally developed ( Fig. 13J )................................................................................third instar larva

Figures

FIGURE 13. a, Homothyrea inornatipennis, first instar larva, thoracic spiracle (orig. Šípek et al. 2012b); b, H. inornatipennis, second instar larva, thoracic spiracle (orig. Šípek et al. 2012b); c, Cetonia aurata pisana, second instar larva, thoracic spiracle (France, Corsica isl, Porticcio env. 30.iv.2002, Šípek lgt.); d, C. aurata pisana (France, Corsica isl, Porticcio env. 30.iv.2002, Šípek lgt.), third instar larva, thoracic spiracle; e, Oxythyrea pantherina, third instar larva, cranium (orig. Šípek 2005); f, Tropinota (Epicometis) hirta, third instar larva, cranium (orig. Šípek 2005); g, Oxythyrea pantherina, third instar larva, epipharynx, (orig. Šípek 2005); h, Tropinota (Epicometis) hirta, third instar larva, epipharynx, (orig. Šípek 2005); i, C. aurata pisana, (France, Corsica isl, Porticcio env. 30.iv.2002, Šípek lgt.), second instar larva, raster; j, C. aurata pisana, (France, Corsica isl, Porticcio env. 30.iv.2002, Šípek lgt.), third instar larva, raster.