A new amber representative of the genus Ectobius Stephens, 1835 (Blattodea: Ectobiidae) from Storeblt (Denmark)

A new fossil cockroach, Ectobius danekrae sp. nov., is described on the basis of a single male adult individual from late Eocene Danish amber. This is the third representative of the genus Ectobius Stephens, 1835 from Eocene ambers. The new species exhibits plesiomorphic characters of small right stylus and subsymmetrical claws, compared to the known fossil and living species of the genus. The references to Ectobius balticus (Germar et Berendt, 1856) and Margattea Shelford, 1911 sp. presence in Danish amber are insufficient.

A new species of the genus Cheiloceps Uhler, 1895 (Hemiptera: Fulgoromorpha: Issidae) from the Dominican amber

A new species of the planthopper genus Cheiloceps Uhler, 1895 (Issidae, Issinae, Thioniini), Cheiloceps magnifrons sp. nov., is described from the Dominican amber. Issidae fossils are briefly discussed.

A new genus and species of Encyrtidae (Hymenoptera: Chalcidoidea) with a four-segmented funicle from late Eocene Baltic amber

Electrocerus brevifuniculatus Simutnik gen.etsp. nov. is described and illustrated based on a female specimen from late Eocene Baltic amber. Placement of the new genus in the subfamily Encyrtinae is supported by the presence of a filum spinosum on the linea calva and the hypopygium not reaching the metasomal apex. A key to the genera of late Eocene Encyrtinae is provided. The new taxon differs from all known extinct and most extant encyrtids by its four-segmented female funicle.

New Limaiinae (Neuroptera: Chrysopidae) from the early Eocene Fur Formation, Denmark, including an unexpected finding of a Mesozoic genus

Two species of Limaiinae (Chrysopidae) are described from the early Eocene Fur Formation of Denmark: Mesypochrysa nielseni sp. nov. and Limaiinae gen. et sp. A. All forewing character states of M. nielseni sp. nov. are similar to those of the widely distributed Mesozoic genus Mesypochrysa Martynov, 1927, which was formerly known from the Middle Jurassic to mid-Cretaceous. Limaiinae gen. et sp. A is represented by an incomplete forewing. Although it differs from other species known from the formation, we refrained to name it pending a more complete specimen. The relatively high diversity of Limaiinae in the early Eocene of Denmark, with at least by two genera and four or five species is surprising. This diversity in the Fur Formation is nearly equal to that of Nothochrysinae.

Description of a new genus and species of Encyrtidae (Hymenoptera: Chalcidoidea) from Danish amber, based on a male specimen featuring an antenna with a distinct anellus

Electroanellus belokobylskiji Simutnik gen. et sp. nov. (Hymenoptera: Encyrtidae) is described and illustrated based on a male specimen from late Eocene Danish amber. The presence of an anellus between the pedicel and the first funicular segment is the main difference between the new taxon and most extant encyrtids, as well as all described fossil species. The new fossil also differs from all known Eocene Encyrtidae by its relatively short marginal vein, which is as long as broad. The placement of the new genus in the subfamily Tetracneminae is supported by the absence of the filum spinosum of the linea calva.

Discovery of a new extinct spider wasp (Hymenoptera, Pompilidae) from Eocene Rovno amber

Paleogenia waichertae Loktionov, Lelej et Perkovsky, sp. nov. is a new species of extinct spider wasps. This new species is a second record of Pompilidae from Rovno amber, third yet known species of the extinct genus Paleogenia Waichert et Pitts, 2016 and 26th known extinct species of spider wasps. Sex of the holotype of the species Paleogenia indomini Colombo et Waichert, 2023 is clarified (male not female). A key to males of Paleogenia is provided.

Beyond the Limits of Light: An Application of Super-Resolution Confocal Microscopy (sCLSM) to Investigate Eocene Amber Microfossils

Amber is known as one of the best sources of fossil organisms preserved with exceptional fidelity. Historically, different methods of imaging have been applied to amber, including optical microscopy and microtomography. These methods are sufficient to resolve millimeter-scaled fossils. However, microfossils, such as microarthropods, require another resolution. Here, we describe a non-destructive method of super resolution confocal microscopy (sCLSM) to study amber-preserved microfossils, using a novel astigmatid mite species (genus Histiogaster, Acaridae) from Eocene Rovno amber as a model. We show that the resolution obtained with sCLSM is comparable to that of scanning electron microscopy (SEM) routinely used to study modern mites. We compare sCLSM imaging to other methods that are used to study amber inclusions and emphasize its advantages in examination of unique fossil specimens. Furthermore, we show that the deterioration of amber, which manifests in its darkening, positively correlates with its increased fluorescence. Our results demonstrate a great potential of the sCLSM method for imaging of the tiniest organisms preserved in amber.

Eocene aposematic patterns persist in modern European Lycidae beetles despite the absence of co-mimics

Ancient aposematic signals might have evolved under different ecological circumstances. Using European Cenozoic amber and phylogenetic reconstruction, we evaluated the evolution of net-winged beetle aposematism. We describe Priabonian Hiekeolycus winkleri sp. nov. from Baltic amber, review known fossil species, and suggest earlier high diversity and morphological conservativeness of European Lycidae since the Eocene. We hypothesize the presence of red and black/red aposematic patterns in Eocene Europe. The analyses suggest the Oligocene to Miocene dispersal of additional species from East Asia and their advergence to autochthonous patterns. Recently dispersed lycids have retained similarities with their East Asian relatives. Net-winged beetles are rare in Europe after the Quaternary climatic oscillations, and we hypothesize a currently relaxed selection for shared aposematic signals. Neophobia, and eventually inborn rejection of brightly colored prey, putatively preserved ancient aposematism under changing conditions. Evidence from paleontology and phylogenetics can provide insight into the long-term persistence of old adaptations under changing conditions.

Unexpected Diversity of Xenoscelinae in Priabonian European Amber: The Third Xenosceline Species from Rovno Amber

Xenophagus simutniki sp. n. is described from a late Eocene Rovno amber specimen. The new species is similar to the fossil Xenophagus popovi Lyubarsky et Perkovsky, 2017 from the late Eocene Baltic amber (W Russia), differing in the medially notched anterior margin of the pronotum. The Rovno xenosceline fauna is the richest among both extant and extinct faunas. This fauna includes the extinct genera Xenophagus Lyubarsky & Perkovsky, 2017 and Xenohimatium Lyubarsky & Perkovsky, 2012, which are closest to the extant Mediterranean Xenoscelis Wollaston 1864 and the representative of the extant boreal genus Zavaljus Reitter, 1880. A key to extinct species of the subfamily Xenoscelinae is presented. The possible reasons of xenoscelines abundance in European amber forests are discussed.

Balticalcarus archibaldi Simutnik Gen. et sp. n. (Chalcidoidea, Encyrtidae) with the Unusually Small Mesotibial Spur from Baltic Amber

Balticalcarus archibaldi Simutnik, gen. et sp. n., is described and illustrated based on a female specimen from late Eocene Baltic amber. The new genus is characterized by the absence of a filum spinosum, a "boat"-shaped hypopygium enclosing the ovipositor, reaching far past the apex of the syntergum, the presence of a line of long setae along the entire costal cell of the hind wing, and a transverse line of thickened setae alongside the hyaline spur vein. Moreover, like most previously described Eocene Encyrtidae, the new taxon differs from the majority of the extant ones by a number of morphological features. The new fossil differs from most extant and all known fossil Encyrtidae by its unusually small, thin, smooth (without microsetae) mesotibial spur.

Termite Valkyries: Soldier-Like Alate Termites From the Cretaceous and Task Specialization in the Early Evolution of Isoptera

In several insect eusocial lineages, e.g., some aphids, thrips, ants, some stingless bees, and termites, task specialization is brought to its climax with a sterile soldier caste solely devoted to colony defense. In Isoptera, while the reproductives are defenseless, the soldiers have unique morpho-physiological specializations whose origin and evolution remain unresolved. Here we report on two instances of Cretaceous fossil termite reproductives belonging to different families († Valkyritermes inopinatus gen. et sp. nov. and an unpublished specimen from the Crato Formation), with intriguing phragmotic soldier-like heads and functional wings. These individuals, herein called Valkyries, are the first termite reproductives known with defensive features and suggest that phragmosis arose at least in the Early Cretaceous. Valkyries resemble modern neotenic soldiers except for their complete wings. Their discovery supports the hypothesis that the division between reproductive (indicated by the winged condition of Valkyries) and defensive tasks (indicated by the phragmotic head) has not always been complete in termite history. We explore two alternative scenarios regarding the origin of Valkyries (i.e., relatively recent and convergent origins vs. plesiomorphic condition) and discuss how they might relate to the development of soldiers. We argue that, in both cases, Valkyries likely evolved to face external threats, a selective pressure that could also have favored the origin of soldiers from helpers. Valkyries highlight the developmental flexibility of termites and illustrate the tortuous paths that evolution may follow.

The first fossil Coleoptera record from the Volyn Region, Ukraine, with description of a new Glesoconomorphus (Coleoptera, Mycteridae) in syninclusion with Winterschmidtiidae (Acari) and a key to species

Glesoconomorphusekaterinae sp. nov. (Coleoptera, Mycteridae), representing the first ever fossil species of Coleoptera from the Volyn Region of Ukraine and the first mycterid from late Eocene Rovno amber, is described and illustrated. A key to species of the fossil mycterid genus Glesoconomorphus Alekseev, Pollock & Bukejs, 2019 is presented. The systematic position of Glesoconomorphus within Eurypinae J. Thomson, 1860 is briefly discussed. The oldest finding of phoretic Winterschmidtiidae Oudemans, 1923 mites, found on the type specimen of the new beetle species, is reported.

A new fossil species of the genus Parasinalda Heiss amp; Golub (Hemiptera: Heteroptera: Tingidae) from Upper Eocene Rovno amber

Parasinalda sukachevae sp. nov. (Hemiptera: Heteroptera: Tingidae: Tinginae: Phatnomini) is described based on one specimen from Eocene amber of the Rovno region (Ukraine). Similarities and differences to closely related species Parasinalda baltica (Drake, 1950), P. froeschneri (Golub Popov, 1998), and P. groehni Heiss Golub, 2013 are discussed, and a key to the four known species of the genus is provided.

A new species of Lonchodryinus (Hymenoptera, Dryinidae) from Upper Eocene Baltic amber

Lonchodryinus groehni sp. nov. (Hymenoptera: Chrysidoidea: Dryinidae) is described from Baltic amber. The new species is close to L. balticus Olmi Guglielmino, 2012, but it can be distinguished for the different OPL/POL ratio and 2r-rsRs vein of the fore wing. A key to the fossil species of Lonchodryinus and a comparison with the extant species L. ruficornis (Dalman, 1818) are presented.

First record of tiger beetles (Coleoptera, Cicindelidae) from Rovno amber, with the description of a new genus and species

A new fossil tiger beetle species, Goriresina fungifora gen. n., sp. n. (Coleoptera, Cicindelidae), is described from Eocene Rovno amber. The new genus belongs to the subtribe Iresiina, tribe Cicindelini, due to the glabrous head, the labrum with six submarginal setae (latero-basal setae very long) and two apical teeth with notch between them, the glabrous and globular pronotum, the lack of setae on the metepisternum and metepimeron, as well as on the visible parts of abdominal sternites, the single long seta each on the fore- and mesotrochanter. The new species is characterized by the long and moderately convex labrum, two clypeal setae, the elongate and apicad converging elytra with an angularly, but smoothly rounded apex, the small and sharp sutural spine, the probable presence of an apical portion of the elytral humeral spot, a slightly sinuate, transverse medial fascia with an extended and downward directed apical portion, and a slightly transverse basal portion of the apical spot. This is the first record of a tiger beetle in Rovno amber and only a fourth well-preserved Cicindelidae from fossil resins.

Mosquitoes (Diptera: Culicidae) in Eocene amber from the Rovno region, Ukraine

Culex ekaterinae sp. nov. is described based on an adult male embedded in amber from the Rovno region, northwestern Ukraine. The new species is compared with its presumed closest known relative, i.e. Culex erikae Szadziewski et Szadziewska, 1985 described from adults in Baltic amber. The two species exhibit distinct differences in the size of the main body parts, including the antenna, maxillary palpus and proboscis, as well as in the venation of the wing, the structure of the ungues and male genitaliacharacters crucial in the diagnosis of adult mosquitoes. A redescription of Culiseta gedanica Szadziewski et Gika, 2011, to date known from a single adult male, is presented based on a male in amber from Voronki, Rovno region. A tabulation of fossil Culicidae with their geological ages is provided.

Protomauroania mikhailovia new species of malachite beetles (Coleoptera, Dasytidae) in Rovno amber

A new species of malachite beetles, Protomauroania mikhailovi Tshernyshev Perkovsky, sp. n. is described from late Eocene Rovno amber. The new beetle is the second species of the Eocene fossil genus Protomauroania Tshernyshev, 2021 that was first recorded in Rovno amber and shows fauna similarity of dasytids in Baltic and Rovno amber. The new species is typical owing to the following characters: antennae with 5-segmented wide club, surface covered with dark-brown long semi-erect thin setae, and the ultimate ventrite (apical sternite) simple, narrow, not depressed. Digital high resolution pictures of the beetle are provided.

A new species of Plectrocnemia (Trichoptera: Polycentropodidae) from Rovno amber

A new caddisfly species Plectrocnemia kirmikhia sp. nov. (Polycentropodidae) is described from Priabonian Rovno amber (Upper Eocene, 33.937.8 million years old). Now the family Polycentropodidae is represented in Rovno amber by 16 named species, and the genus Plectrocnemia includes 5 described species in this locality.

A new species of the genus Dorytomus Germar, 1817 (Coleoptera, Curculionidae) from Rovno amber

A new species, Dorytomus mikhailovi sp. n., from late Eocene Rovno amber is described and illustrated. The new species is similar to D. groehni Bukejs et Legalov, 2019 from Baltic amber but differs in the shorter rostrum, dorsum covered with denser decumbent hairs and erect to semierect scale-like setae, and smaller body sizes. It is distinguished from D. bukejsi Legalov, 2020 from Baltic amber by the densely punctate pronotum, longer rostrum and wide elytral interstriae. The new species differs from D. vlaskini Legalov et al., 2019 from Rovno amber by the elytral interstriae covered with decumbent hairs and erect to semierect scale-like setae, shorter rostrum and coarsely punctuate pronotum. It is the first named curculionid beetle from the Olevsk amber locality, and the eleventh amber species reported from the Zhitomyr region. The presence of seven species of Dorytomus suggests a rather high diversity of Salicaceae in the late Eocene amber forests of Europe. It corresponds well with other principal Holarctic species in European amber biotas.

A new bizarre species of Euconnus (Cladoconnus) in Upper Eocene Rovno amber (Coleoptera: Staphylinidae: Scydmaeninae)

Despite being among the most species-rich extant animal genera, Euconnus Thomson is rare in fossil record. Merely six species found in relatively young, Eocene and Oligocene ambers have been placed in this genus, which currently includes over 2,600 extant nominal species distributed worldwide. We describe †Euconnus nathani sp. n., the first extinct, unambiguously placed member of the broadly distributed, extant Palaearctic subgenus Cladoconnus Reitter, based on a unique male specimen in Upper Eocene Rovno amber, Ukraine. The male of the new species has monstrously modified antennae, in general structure showing close similarities to those of extant congeners, but the modification of antennomere 8 is so profound and bizarre that this one antennal segment alone is sufficient to identify adults of E. nathani.

Harvestmen (Arachnida: Opiliones) in Eocene Rovno amber (Ukraine)

Six species of harvestman (Arachnida: Opiliones) are documented from the Eocene Rovno amber in Ukraine. From the suborder Eupnoi we record Caddo dentipalpus (C. L. Koch Berendt, 1854) (Caddidae), Amilenus deltshevi Dunlop Mitov, 2009 (Phalangiidae) and Dicranopalpus ramiger (C. L. Koch Berendt, 1854) (family incertae sedis). To these we add a new phalangiid, Metaphalangium martensi sp. n., which is the oldest representative of the Recent genus Metaphalangium Roewer, 1911 and new genus for the amber fauna. From Dyspnoi we record Sabacon claviger (Menge, 1854) (Sabaconidae) and propose Parahistricostoma gen. n. (Nemastomatidae), to accommodate Nemastoma tuberculatum C. L. Koch Berendt, 1854, yielding Parahistricostoma tuberculatum (C. L. Koch Berendt, 1854) comb. n. The Rovno harvestman fauna is briefly compared to both Baltic and Bitterfeld amber. The fossil species, C. dentipalpus, A. deltshevi, D. ramiger and P. tuberculatum occur in all three ambers, and S. claviger is found in Baltic and Rovno amber. The only genus and species unique to Rovno amber is thus our new taxon M. martensi. The composition of the Rovno opilionid fauna is discussed in the context of late Eocene palaeoenvironment and ecological preferences and the fossils are compared to the distribution of extant harvestman taxa. The oribatid mite Platyliodes ensigerus Sellnick, 1919 (Acari: Neoliodidae) is reported from Rovno amber for the first time.

First Bocchus Ashmead (Hymenoptera: Dryinidae) from Upper Eocene Rovno amber: B. schmalhauseni sp. nov

A new species of pincer wasps, Bocchus schmalhauseni sp. nov. (Dryinidae) is described from Rovno amber (Ukraine). The amber piece was collected in the Vladimirets District in the north-west of the Rovno region. Taking into account this new record, a total of five species of Dryinidae are registered from Rovno amber. A key to the fossil species of Bocchus Ashmead is presented. The possible reasons for the different distribution of Dryinus species on both coasts of Subparathetys are discussed.

The first Cacomorphocerus species (Coleoptera, Cantharidae) from Rovno amber: a second species of the genus with 11-segmented antennae

A new species of soldier beetles of the subfamily Cantharinae, Cacomorphocerus meridionalis sp. nov., is described from Upper Eocene Rovno amber. It is the second time that a Cacomorphocerus species with 11-segmented antennae has been discovered. The status of the tribe Cacomorphocerini is discussed.

Diversity of Eocene Ripiphoridae with descriptions of the first species of Pelecotominae and larva of Ripidiinae (Coleoptera)

The Eocene records of the beetle family Ripiphoridae are evaluated and summarized. A new species of Pelecotominae belonging to the genus Clinops, C. svachaisp. nov. from Baltic amber, is described and figured. The female holotype of C. svachai is the first Palaeogene member of this subfamily to be identified. In addition, a male of a different unidentified genus of Pelecotominae, preserved as an inclusion in Baltic amber, is documented. The first Palaeogene primary larva of Ripiphoridae is described from Sakhalin amber and is compared with all other primary larvae of this family. The larva is attributed to Ripidius (Ripidiinae) and bears some unique characters absent in larvae of this extant genus. A putative record of Ripiphorus (Ripiphorinae) in the Berendt collection is identified as a member of Ripidius. Distribution of Eocene species are compared with those of their closest extant relatives and mapped. Based on the fossil record and the distribution of extant South African species of Clinops, this genus is tentatively thought to be an example of an Eocene relict, while the extant pelecotomine genus Scotoscopus from the East Mediterranean is considered to be an Oligocene–Miocene relict as its distribution corresponds with the geological history of the Aegais landmass.

First record of Cicadellidae (Insecta, Hemiptera, Auchenorrhyncha) from Eocene Sakhalinian amber

Sakhalotettixeocenicusgen. & sp. nov., the first leafhopper reported from middle Eocene Sakhalinian amber, is described and illustrated. The fossil cicadellid resembles modern Xestocephalini and Bathysmatophorini in some respects but, because of its unique combination of traits, cannot be placed with certainty in either group, or in any other modern cicadellid subfamily. It is, therefore, considered to be incertae sedis within Cicadellidae.

A new species of Succinoraphidia Aspöck amp; Aspöck, 2004 (Raphidioptera: Raphidiidae) from the late Eocene Rovno amber, with venation characteristics of the genus

Succinoraphidia radioni sp. nov. (Raphidiidae) is described from the late Eocene Rovno amber, Ukraine. The genus also includes two species from contemporaneous Baltic amber, i.e., S. exhibens Aspöck Aspöck, 2004 and S. baltica (Carpenter, 1957), comb. nov. The venation of Succinoraphidia is analysed. It possesses several plesiomorphic character states at the family level, and the monotypic subfamily Succinoraphidinae represents a basal group within the family or possibly even a potential stem group of Raphidiidae. All diagnostic character states of Succinoraphidia (except the structure of the pterostigma) are found in a few Cretaceous species of the paraphyletic Mesoraphidiidae, but some of these are not found in the extant Raphidiidae.

Staminate flower of Prunus s. l. (Rosaceae) from Eocene Rovno amber (Ukraine)

The late Eocene ambers provide plethora of animal and plant fossils including well-preserved angiosperm flowers from the Baltic amber. The Rovno amber from NW Ukraine resembles in many aspects the Baltic amber; however, only fossilized animals and some bryophytes have yet been studied from the Rovno amber. We provide the first detailed description of an angiosperm flower from Rovno amber. The flower is staminate with conspicuous hypanthium, double pentamerous perianth and whorled androecium of 24 stamens much longer than the petals. Sepals are sparsely pubescent and petals are densely hirsute outside. The fossil shares important features with extant members of Prunus subgen. Padus s. l. (incl. Laurocerasus, Pygeum and Maddenia), especially with its evergreen paleotropical species. It is described here as a new species Prunus hirsutipetala D.D.Sokoloff, Remizowa et Nuraliev. Our study provides the first convincing record of fossil flowers of Rosaceae from Eocene of Europe and the earliest fossil flower of Prunus outside North America. Our record of a plant resembling extant tropical species supports palaeoentomological evidences for warm winters in northwestern Ukraine during the late Eocene, as well as suggesting a more significant role of tropical insects in Rovno amber than inferred from Baltic amber.

Discovery of the first pincer wasp (Hymenoptera, Dryinidae) from Rovno amber

Dryinidae (Hymenoptera: Chrysidoidea) are recorded for the first time from Rovno amber (Ukraine), following the discovery of one female of Dryinus janzeni Olmi. Holotypes of D. balticus (Olmi) and D. bruesi (Olmi) previously assigned to the Baltic amber, were actually collected on the coast of Denmark, so that they have to be recorded as specimens in Scandinavian (Danish) amber. As a result, true records of Dryinus species of group 3 (Olmi 1993) in Baltic amber are three: D. janzeni, D. bruesi, because of a second specimen found in true Baltic amber, and D. velteni Olmi. Dryinidae are the 33th hymenopteran family known from Rovno amber. Three species, D. janzeni, D. bruesi and D. balticus are known from understudied Rovno and Scandinavian amber originated from the warmer south coast of the Subparathetys. Dryinus janzeni is the 115th hymenopteran species known from Rovno amber and the first Dryinus record from Ukraine.

Archaeocercus gen. nov. (Hymenoptera, Chalcidoidea, Encyrtidae) from Late Eocene Rovno Amber

Archaeocercus schuvachinae, gen. et sp. nov., is described and illustrated based on a female specimen from Rovno amber (Ukraine). This fossil genus is characterized by the apical position of cerci on metasoma, absence of filum spinosum on distal margin of linea calva on forewings, triangular hypopygium reaching metasomal apex, mesoscutum with incomplete notauli, long veins on forewings and apically expanded antennae. A brief comparative morphological analysis of some structures of the extinct and extant Encyrtidae is provided. The new genus is considered unplaced within Encyrtidae.

Third contribution on Rovno amber silken fungus beetles: a new Eocene species of Cryptophagus (Coleoptera, Clavicornia, Cryptophagidae)

Cryptophagus alexagrestis Lyubarsky & Perkovsky, sp. n. is described based on a fossil inclusion in Late Eocene Rovno amber (Ukraine). The new species is similar to the extant Cryptophagus skalitzkyi Reitter and Cryptophagus dilutus Reitter, differing from the latter by having a very transverse, short and dilated 10th antennal segment, and from the former by the very elongate segments of the flagellum.