Protaetia (Cetonischema) speciosissima (Scopoli, 1786)
Family: Scarabaeidae
This is the largest golden-headed beetle in Europe, reaching a body length of 22 - 28 mm (rarely up to 34 mm). The robust body is entirely coloured green to golden-green with a typical thick to glassy sheen, which may have a yellow-red, sometimes blue tinge. The body is smooth, sparsely hairy underneath. On the head there are ten-articulate antennae, ending in a three-articulate stalk and a characteristic square plate. The scutellum is large, triangular and with a rounded apex. The process of the mesosternum is large, smooth, unpeeled and without a transverse rib at the apex.
The first beetles appear in the last days of April and are found until mid-September, with the peak of swarming in late June and July. They prefer to fly on hot and sunny but windy days. They fly fast and usually high in the treetops. The species is saproxylic and strongly attached to old deciduous trees (especially oaks but also limes, willows and other deciduous trees). It prefers light oak woodlands, groves and old parks with plenty of hollows and old trees. Protaetia speciosissima occurs in Europe (except Scandinavia and the British Isles) as far as the European part of Russia. This species is very rare throughout its range and is declining in many parts. In the Czech Republic, it is very local and rare: in Bohemia (mainly Polabí and around Prague, eastern Bohemia) and in southern and central Moravia. The beetles take their food in the form of fermented sap oozing from cracks in tree trunks and from fruit. Only sporadically, unlike other representatives of the genus Protaetia, they fly to flowers and inflorescences.
The beetles mate during peak activity from June to August. The larvae feed in the high cavities of trunks and branches in the crowns of deciduous trees, especially oaks, less frequently poplars, cherries, limes, beeches, and sporadically willows and elms. A three-month diapause during winter is necessary for larval development. After diapause, the larvae build their cocoon in spring and hatch in early summer. The exact length of development in nature is not documented in detail, but based on information on related species and laboratory rearing, it can be estimated that complete development from egg to adult takes 1 - 2 years.
Picture Source: Makarov, 2007
