Evgeny E. Perkovsky

An Eocene Bee in Rovno Amber, Ukraine (Hymenoptera: Megachilidae)

Abstract A new species of fossil bee is described and figured in Late Eocene amber from the Rovno region of the Ukraine. Ctenoplectrella zherikhini n.sp. (Megachilinae: Ctenoplectrellini), is similar to those species known from the slightly older Baltic amber (middle Eocene). This is the first bee discovered in the Rovno amber and the fourth species for its genus. The presently known megachilid bee fossils are summarized and the geological history of the family reviewed.

Diversity of Scydmaeninae (Coleoptera: Staphylinidae) in Upper Eocene Rovno amber

Among nearly 1270 inclusions of Coleoptera found in Upper Eocene Rovno amber, 69 were identified as ant-like stone beetles (Scydmaeninae); 34 were possible to unambiguously determine to the tribal level and were studied in detail. Rovnoleptochromus ableptonoides gen. & sp. n. (Mastigitae: Clidicini), Vertheia quadrisetosa gen. & sp. n. (Cephenniitae: Eutheiini), Cephennomicrus giganteus sp. n. (Cephenniitae: Cephenniini), Glaesoconnus unicus gen. & sp. n. (Scydmaenitae: Glandulariini), Rovnoscydmus frontalis gen. & sp. n. (Scydmaenitae: Glandulariini; type species of Rovnoscydmus), Rovnoscydmus microscopicus sp. n., Euconnus (incertae sedis, near Cladoconnus) palaeogenus sp. n. (Scydmaenitae: Glandulariini), and Stenichnus (s. str.) proavus sp. n. (Scydmaenitae: Glandulariini) are described. Additionally, specimens representing one undescribed species of Vertheia, one of Cephennodes, five of Cephennomicrus, one of Euconnus, one of Microscydmus are recorded, and nine specimens representing an unknown number of species of Rovnoscydmus (and two putative Rovnoscydmus), one Euconnus (and one putative Euconnus), two putative Microscydmus and one putative Scydmoraphes were found in the studied material. The composition of Scydmaeninae fauna in Rovno amber is discussed in the context of ecological preferences and distribution of extant taxa. It is concluded that subtropical and tropical taxa were present in the region where Rovno amber has formed, most notably the second genus and species of the extant tribe Clidicini known from the Eocene of Europe, and six species of the extant genus Cephennomicrus, for the first time found in the fossil record. An annotated catalog of nominal species of Scydmaeninae known in the fossil record is given.

Orthoclads from Eocene Amber from Sakhalin (Diptera: Chironomidae, Orthocladiinae)

Four Middle Eocene orthoclad species, Heterotrissocladius naibuchisp. n., Paraphaenocladius nadezhdaesp. n., Pseudosmittia kodrulaesp. n. and Smittia sukachevaesp. n.. are described and figured. Based on the combination of the diptera fauna composition and paleobotanical data, suggestions on the climate and habitats of the Sakhalin amber forest are given.

New gall midges of the tribe Leptosynini (Diptera, Cecidomyiidae) from the Late Eocene ambers and the classification of the supertribe Heteropezidi

Three new genera and 27 new species of gall midges are described from the Late Eocene ambers: Henria baltica sp. nov., Frirenia manca sp. nov., F. musicata sp. nov., Leptosyna samlandica sp. nov., L. fastosa sp. nov. from Baltic amber and H. xystica sp. nov., H. liquida sp. nov., Stellasegna vlaskini gen. et sp. nov., S. vaporea sp. nov., S. nexa sp. nov., Rasnitsia verticosa gen. et sp. nov., F. rohdendorfi sp. nov., F. schevchenkoi sp. nov., F. melica sp. nov., F. lukashevichae sp. nov., F. leporidis sp. nov., F. marmarygma sp. nov., F. vesana sp. nov., Vincinescia alisae gen. et sp. nov., L. margarita sp. nov., L. munifera sp. nov., L. sukachevae sp. nov., L. assa sp. nov., L. larga sp. nov., L. vegeta sp. nov., L. vaticina sp. nov., and L. shcherbakovi sp. nov. from Rovno amber. Strobliella capitata Fedotova is redescribed as Henria capitata (Fedotova, 2004) (comb. nov.). Diagnoses of Henria (= Electroxylomyia Nel et Prokop, syn. nov.), Frirenia, and Leptosyna are revised. As a result, Henria comprises 3 extant and 5 extinct (Late Eocene) species, including H. eocenica (Nel et Prokop), comb. nov. (= Electroxylomyia eocenica), Frirenia comprises 1 extant and 10 Late Eocene species, and Leptosyna comprises 3 extant and 11 Late Eocene species. The tribe Heteropezini is elevated to the supertribal rank (Heteropezidi) and included in the subfamily Lasiopterinae. Leptosynini is treated as a separate tribe, and Lasiopterinae is considered as part of Cecidomyiidae s. str. (i.e., excluding Lestremiidae). Keys to the tribes and genera of Heteropezidi and to species of Henria, Stellasegna, Frirenia, and Leptosyna are provided. The gall midge faunas of the Rovno and Baltic ambers are compared. Phylogenetic relationships within the supertribe are hypothesized.

Eohelea sinuosa (Meunier, 1904) (Diptera, Ceratopogonidae) in Late Eocene ambers of Europe

Differences between ceratopogonid faunas from different Late Eocene ambers are almost as great as between ant faunas and give evidence of their different geographical origins. The greatest similarity is recorded between ceratopogonid faunas of the Rovno and Danish ambers; it manifests itself, in particular, in the presence of Leptoconops, abundant Eohelea sinuosa, and rather frequent occurrence of Meunierohelea. Eohelea sinuosa is the most abundant ceratopogonid species in the Rovno amber. The abundance of Eohelea is probably accounted for by the abundance in these assemblages of small chironomids, with terrestrial larvae; which composed 40% of the Rovno amber chironomid fauna and were probably prey to Eohelea. It is shown for the first time that Ceratopogonini with feminized male antennae (with reduced plume) occur three times as often in syninclusions of specimens of both sexes (63% of all Eohelea inclusions from the Rovno amber);this is evidence that Ceratopogonini with feminized male antennae turned to mating on substrate. This supports the hypothesis of Dinwiddie and Rachootin (2011) that wing organs of female Eohelea were not used for stridulation.

Contribution to the study of the structure of amber forest communities based on analysis of syninclusions in the Rovno amber (Late Eocene of Ukraine)

The composition of syninclusions was analyzed in three representative samples of the Late Eocene Rovno amber. Statistical analysis revealed a stable connection between three pairs of taxa in all three samples, viz., the midges Chironomidae and Ceratopogonidae; the flies Dolichopodidae and aphids Germaraphis; and the mite Glaesacarus rhombeus and Sciara zone dipterans (Sciaroidea, Tipuloidea, etc.). The first pair is interpreted as representing the assemblage of aeroplankton insects; the second, the assemblage of dwellers of the trunks of amber trees; and the third pair, the assemblage of dead wood consumers. The results, although provisional, support the idea that the study of syninclusions is a useful instrument for understanding the structure of past communities.

Biting midges (Diptera, Ceratopogonidae) in amber forest communities based on analysis of syninclusions in Late Eocene Rovno amber

Over 2,500 pieces of unselected Rovno amber (Late Eocene of Ukraine) are studied for their contents of syninclusia depending on amber piece weight class and taxonomic position of syninclusion components. Unlike previous publications (Perkovsky et al. 2010a, 2012), ceratopogonid components enter analysis separately (as genera or genus groups) rather than as entire taxon. This changes the resulting pattern drastically. Instead of two correlation pleiades, the air-plankton one (include biting midges), and the ‘ Sciara zone’ dwellers, we have six pleiades now depending on developmental environments (terrestrial saprotrophs vs . aquatic) and adult behavior (low level fliers and tree trunk visitors vs . air plankton and others which show no preference to tree trunks). Causes of some differences are uncertain.

A new genus and species of dryophthorid weevils (Coleoptera, Dryophthoridae: Stromboscerinae) from the Rovno amber

Stenommatomorphus hexarthrus gen. et sp. nov. (Dryophthoridae: Stromboscerinae) is described from the Late Eocene Rovno amber. This is the first fossil representative of the subfamily. The new genus is most close to Synommatus Pascoe, from which it differs in the pronotum and elytra less coarsely sculptured, the intervals not carinate, and the scutellum present.

Caddisflies from Cenozoic resins of Europe

Analysis of the available data on the findings and taxonomical structure of caddisflies (Insecta, Trichoptera) in the Cenozoic fossil resins of Europe shows that there are four European amber regions (Baltic, Rovno, Saxonian, and Danish) are characterized by a relatively abundant trichopteran fauna, comprising 27 families, 72 genera, and 256 species. These faunas show the dominance of Psychomyioidea (families Polycentropodidae, Psychomyiidae, and Ecnomidae) with Polycentropodidae comprising up to 75% of all records. The amber faunas are second in the dominance of Polycentropodidae only to the terminal Eocene of Florissant (84% of Polycentropodidae). No modern caddisfly species have been found. The amber regions are significantly different in the species composition of Trichoptera although the generic and family structures are similar. Comparison with the modern faunas of Europe shows the absence of advanced Limnephilidae, which are characteristic of the Holocene faunas of Europe, and the rarity of recently abundant Hydropsychidae and Hydroptilidae. The overall composition of amber Trichoptera suggests that it is structurally related to the faunas of Caucasus and Southeastern Asia and might be evidence of seasonally low-contrast (equable) climate in the Late Eocene of Europe.

Review of the Late Eocene Encyrtidae (Hymenoptera, Chalcidoidea) with a description of the first fossil genus with filum spinosum

Glaesus gibsoni gen. et sp. nov. and Eocencnemus gedanicus sp. nov. are described from materials stored in the amber collection of the University of Gdańsk. Eocencyrtus zerovae Simutnik, 2001 is for the first time recorded in the Baltic amber. The encyrtids recorded in Eocene ambers are reviewed, and a key to the known genera is given. The fossil Encyrtidae cannot be placed with confidence in any of the established subfamilies. Their comparative morphology is analyzed. One of the diagnostic characters of the subfamily Encyrtinae, the presence of the filum spinosum, is recorded for the first time for fossil encyrtids (in G. gibsoni).