|
|
|
|
|
|
|
|
|
|
|
The opinion that the common stag beetle and other large beetles become rare and need protection almost everywhere throughout Europe led to establishing a special international program including annual measures in West European countries, aiming to provide conditions for development of xylophylous (saproxylous) beetles. One of the symbols of this program is common stag beetle (see page of our site: on the Symposium on the Conservation of Saproxylous Beetles).
In 2003 emergence of great numbers of this species was observed in Eastern Ukraine. In particular, this beetle appeared in large numbers in Kharkov Region not only in highland oak forests and in parks with old oaks, where it occurs quite regularly every year, but it is also frequently observed even in old forest zones, gardens and foreststands; the latter was reported before to be a relatively rare phenomenon. On some trees with drippling sap or damaged bark hundreds of individuals of adult beetles were recorded at the same time. By the end of July 2003 adult beetles of both sexes were alive, although normally males die during July and mainly females occur in nature.
The reasons of mass emergence of common stag beetles in 2003 remain unknown. Considering the long-term larval development of this species it can be admitted that the reasons could be traced to the year when abundant appearance of larvae and their successful survival during all seasons when they were larvae and pupae was possible. It should be noted that spring and early summer 2003 were dry and hot, although they were preceded by an unusually cold winter with little snow.
Unfortunately, unlike Western Europe, in the CIS no monitoring is conducted of abundance of these interesting beetles, which might have revealed unexpected patterns of population fluctuations reflecting dynamics of different adjoint ecological processes. The common stag beetle is a convenient object of study in this respect, not only because of body size, and easy prediciton of localities where it can be looked for, but also because it has a relatively long period of adult activity, which allows for observations (that should not be necessarily synchronous) on its numbers in different regions. Association of larvae with bark of old trees in good state makes it a possible indicator. Limitation connected with selection of this object is determined primarily with the terms of larval development, its abundance dynamics, and should be correlated with characteristic features of each generation of beetles. It should be noted that common stag beetles are liked by wild boars which can find trees with aggregations of mature larvae and procure them scuffling the ground and rotten parts of trunks and roots.
The major part of this information was sent by our Ukrainian colleagues, mostly by D.V. Vovk, V.N. Gramma, and M.A. Filatov.
We will hope that in our country we will also find enthusiasts interested in this beetle and are included into the international research program of this and other saproxylous species of beetles (see On Symposium on the Conservation of Saproxylous Beetles).
A.G. Kireitshuk
July, 2003