Finds of rare species Phloeostichus denticollis Redtenbacher, 1842 (Coleoptera, Phloeostichidae) and Derodontus macularis (Fuss, 1850) (Coleoptera, Derodontidae) in the Ukrainian Carpathians

Abstract

The results of observing of two rare beetle species, known for a single find, are presented. According to biological features – both of them are saproxylic and fungicolous, whose existence are connected with primeval or old-growth forests ecosystems.

Phloeostichus denticollis Redtenbacher, 1842 – very rare, relict boreo-alpine species with European-Caucasian type of species distribution. In Ukraine it was known by finds from Transcarpathian region for almost one hundred years ago and from Crimea. As relict species they are protected in many countries, in Ukraine they are not entered into the protection list. Obviously, it’s due to the absence of recent founds and absent data of distribution on the territory of Ukraine. Four samples of Ph. denticollis were found during stationary entomological research during 2018-2019  on the upper limit of the forest of the Yavirnyk mountain range, one of mountain massif of north-western part of the Polonynian Beskids of Ukrainian Carpathians.The forests plot, where the species was detected, are presented by phytocenosis of predominance of Fagus sylvatica and Acer pseudoplatanus aged more than 150 years. All plot areas are covered by lying dead wood on different stages of decomposition, inhabited by different saproxylic fungi, mosses and lichens.Ph. denticollis Redt – saproxylic-fungivores species, life cycle of which is connected with deadwood and fungi inhabiting it. Wood residues of living or dead sycamore (Acer pseudoplatanus) create a microhabitat for beetle’s larvas, which feed on fruit bodies of ascomycetes Prosthecium pyriforme on anamorph stage Sepedonium, which grow in the thickness of this tree bark.Inhabitant of nature forest, especially with addition of Acer pseudoplatanus or Acer platanoides, Phloeostichus most often occur under bark of old sycamore, less often under beech (Fagus sylvatica) bark. Derodontus macularis (Fuss, 1850) - european species with limited distribution. In Ukraine D. macularis is known from Ukrainian Carpathian.

In general, on all territories where D. macularis was found it occurs rarely and sporadicly. Distributed in well-preserved deciduous and mixed forests, with lots of dead wood and high humidity.

It is considered as relict of natural forests. Included into the primeval relict saproxylic species list D.macularis is demanding some environmental conditions, especially to humidity and availability of habitat fungi: Ischnoderma resinosum (Schrad.) і I. benzoinum (Wahlenb.). As a relict species it can serve as a bioindicator of natural ecosystems.

Five specimens were collected by hand collecting, on fruit body of Trametes gibbosa on lying stem of Fagus sylvatica in beech forests massif near Uzhhorod. Phloeostichus denticollis Redt. і Derodontus macularis (Fuss) are important indicators of natural forests, so evidence of populations of these species is crucial in terms of assessing forest stands.