HUNGARY, 1-2.VII.2007

Finally, the time has come to find the rare jewel beetle in the nature, the signs of which I found in the last autumn, after the season of the activity of the adults. This is Eurythyrea quercus (Herbst, 1780), which is protected all over Europe and occurs in some national red lists. In Hungary it is also protected by law as one of the nine protected buprestids with theoretical value of 50 000 HUF. Its rarity is due to its way of life and the forestry practice, which doesn’t tolerate presence of dead standing trees. Larval development takes place in old, dry but not rotting trunks of species of Quercus and Castanea sativa, deep in the dry wood, sometimes for ten years. Since only few old trees remained in Europe, the species became very rare, and can be found in extremely low number in deciduous forests. In some cases single old trees or groups of them can support viable populations, as I have seen it last year in the Czech Republic, in southern Moravia. Fortunately, such places can be found in Hungary as well, so we can find this beetle not only by chance at lower and higher altitudes, but with targeted search the life and behaviour of this six-legged jewel can be observed. The adults appear in the second half of June and survive into July. They are thermophilous, only active in the heat of the day; rainy weather or strong wind make them inactive.

I was already in the site at dawn and I couldn’t sleep because of the excitement, so I was able to look on the moonset.

The first rays of the sun started to heat the canopy of the old trees.

“Methuselahs” like these can be suitable host trees of the beetle. (Quercus robur L.)

The time of stag beetles, Lucanus cervus (Linnaeus, 1758), is over. I found dozens of these beetles dead, mostly chopped up by ants.

A bit of wood found in the last autumn, full of holes.

This could be a fresh exit hole of a female.

There are many exit holes on the trunks of almost every old tree gnawed by Cerambyx cerdo Linnaeus, 1758.

The number of holes suggests a strong population.

In the morning the sun was rising higher and higher, and the temperature was increasingly hotter, so it was well worth watching the canopy.

By standing under the trees, we were watching the launching beetles.

The perching beetles may be caught with a long net, because they rarely come down the shrub layer.

Females are rare in the net. The number of females may be lower than males.

The first female is green, with blue legs, and 18mm long.

The second is a somewhat reddish and bigger (19mm) specimen.

Males are always smaller, their colour is mostly green.

Reddish coloured male.

A male with blue elytra.

The males are flying around the trees, looking for females sitting on the leaves. When they find one, copulation begins immediately.

Other species of buprestids live in the canopy of oaks as well: Coraebus fasciatus (Villers, 1789).

This male was also caught by net.

After sunset, with the help of torches, we found other beetles:

A rare click beetle: Lacon querceus (Herbst, 1784)

Several specimens of the longhorn Prionus coriarius (Linnaeus, 1758) were also seen.

Translated by O. Merkl & T. Németh