Protaetia cuprea (Fabricius, 1775)
This widespread Western Palaearctic species occurs throughout Europe and extends through Asia Minor and Russia as far as the Pacific although it is represented in many regions by distinct subspecies, about twenty in Europe alone. The nominate subspecies occurs in Southern Europe; Switzerland, Italy, Corsica and Sardinia, while subspecies metallica (Herbst, 1782) occurs throughout the region, with the exception of the Iberian Peninsula, and extends north to the UK and the far north of Fennoscandia. Many subspecies are sympatric and most European countries have a varied selection but several are very restricted e.g. P. c. olivacea (Mulsant, 1842) is endemic to France, P. c. levantina (Schatzmayr. 1938) is endemic to one of the Northern Aegean Islands and P. c. brancoi (Baraud, 1992) occurs only on the Iberian Peninsula. This is all very confusing, especially as there are another twenty-five or so species representing five subgenera in Europe, but among the UK fauna our single representative is distinct enough to be easily recognized. Ssp. metallica is generally common throughout Europe and often abundant in southern and central regions, it occurs from lowlands to the upper limit of the tree-line in mountain areas and in some regions it is often a pest of commercially-grown fruit and roses. But despite this it is very local and scarce in the UK, being more or less restricted to the Scottish Highlands although there are older records from Northern England and Anglesey and a few more recent ones from Southern England-which may represent continental immigrants and have nothing to do with the Scottish populations. Adults are active from May until August, they are diurnal and active in bright sun when they visit flowers of a range of woody and herbaceous plants to feed on pollen and nectar, they also feed on foliage and fruits and are strongly attracted to sap runs. Mating occurs after a period of feeding and continues through the season, usually on flowers, and females oviposit among suitable host material. Larvae are detritivores, they develop in the lower layers of active nests of the Wood Ant (Formica rufa L.), on the continent also in nests of the Hercules Ant (Camponotus herculeanus (Linnaeus, 178)), they sometimes occur among woody debris in abandoned nests and sometimes, though rarely, among decaying deciduous leaf litter. Larvae overwinter and it is likely that they normally develop over two years, pupating in the spring to produce new-generation adults soon after, but adults occasionally occur throughout the year and so the situation is more complex and probably depends on the season and local factors such as food supply. Adults are usually observed in flight or on flowers, and despite the their very local occurrence they can be very common where they occur; in Southern and Eastern Europe they sometimes occur in huge numbers in orchards and so rather inevitably, pheromone traps and soil insecticides are available that very efficiently attract and kill them in large numbers before the fruit begins to grow. In the UK they will come readily to fermenting fruit traps.
Protaetia cuprea 1
Protaetia cuprea 2
Protaetia cuprea 3
Protaetia cuprea 4
16-22 mm. UK specimens are metallic green or reddish-green above and reddish below, with or without the white flecks seen on the elytra of Cetonia aurata (Linnaeus, 1758), but continental specimens vary from black to bright metallic violet or blue and many forms are bicoloured with the forebody contrasting with the elytra. Distinguished from our other chafers, except for Cetonia, by the glabrous body, large scutellum and elevated mesepimera which are visible from above. From Cetonia it may be distinguished by the smoothly rounded elytral apex and the form of the mesosternal process which is coarsely punctured and flat or slightly sinuate across the apex, in Cetonia the elytral apex is sinuate and the mesosternal process is rounded apically and sparsely and very finely rounded.
More metallic general appearance.
Elytral apex sinuate before suture (Fig. a)
Fig. a) Elytral apex in Protaetia cuprea (left) and C. aurata (right).