EXPANDING THE RECORD OF LARVAE OF FALSE FLOWER BEETLES WITH PROMINENT TERMINAL ENDS

Beetle larvae contribute to the overall biomass with a great share, yet they often stay unnoticed and underexplored. Larvae of the group Scraptiidae, also called false flower beetles, lead a life hidden in the wood, not easily accessible for observers. There, they contribute to wood decomposition and carbon cycling. Even though their ecological role is of great importance, these larvae have been comparably rarely studied. This is true for extant as well as fossil representatives of this group. It seems that this knowledge gap is not based on the limited availability of material but results from insufficiently studied material. Here we report new specimens, of which seven are extant and twelve are fossil. Fossil specimens are either from 40-million-year-old Baltic amber (Eocene) or 100-million-year-old Myanmar amber (Cretaceous), the latter representing the oldest record of these larvae. All specimens considered here possess a large, elongated terminal end. We performed an outline analysis of the shape of this terminal end for all so far known larval specimens sufficiently well preserved (in total 33 specimens: 17 extant, 14 Eocene, 2 Cretaceous). There is a recognisable difference between Eocene and extant specimens, yet it remains unclear whether this is due to different represented larval stages or an effect of evolution.

Extant Genus in the Mesozoic: Paleoplatyura Meunier (Diptera: Keroplatidae) Found in the Cretaceous Amber of Myanmar

Three new species of Paleoplatyura Meunier, 1899, i.e., Paleoplatyura agnieszkae sp. nov., P. miae sp. nov., and P. magnifica sp. nov., are described and figured. The concept of the genus is briefly discussed, and its systematic position is clarified. A key to fossil species is provided. The genus Paleoplatyura is described from the Eocene Baltic amber. It is concluded that, in Baltic amber, this group is represented only by the type species, and the identity of the other two species is problematic. No additional specimens have been found so far in this amber. Therefore, the presence of as many as three new species in Burmese amber, certainly belonging to Paleoplatyura, is a confirmation of its occurrence already in the Mesozoic.

Janzenella theia Bremer & Talamas (Platygastroidea, Janzenellidae): a new species from Baltic amber

A new species, Janzenella theia Bremer & Talamas, sp. nov., is described from Baltic amber, which is the second known species of the family Janzenellidae (Platygastroidea). Synchrotron scanning was performed to observe internal structures and external morphology that was occluded by turbidity in the amber matrix surrounding the specimen.

The first fossilized comb-clawed beetle of the genus Asiomira Dubrovina, 1973 (Coleoptera: Tenebrionidae: Alleculinae) from Baltic Amber and notes on the distribution of extant species of the genus

A new species of comb-clawed beetles of the genus Asiomira Dubrovina, 1973 (A. dubrovinae sp. n.) is described from the Eocene Baltic amber. This newly descovered fossil species displays typical generic characters and is the most similar to the extant Asiomira ophtalmica (Seidlitz, 1896). Both species share a similar shape of the pronotum and the flattened posterior angles of the pronotal disc. Asiomira dubrovinae sp. n. can be distinguished from A. ophtalmica by the smaller body size (4.8 mm in contrast to 6–8.12 mm), more serrate antennomeres, and finer and sparser pronotal punctation. Extant species of the genus are distributed in the arid landscapes of Central Asia with the highest diversity occurring in Tajikistan. Therefore the discovery of a new fossil species from Eocene Baltic amber suggests that Asiomira could have a wider range, and the modern distribution of this group is the result of a later secondary expansion of the ancestral representatives that survived in mid-mountain areas with arboreal and shrub vegetation. Relevant corrections to the distribution of extant species, Asiomira ophtalmica (Seidlitz, 1896) and Asiomira firjusana (Dubrovina, 1973), are given.

Clusiomitidae, A New Family of Eocene Fossil Acalyptratae, with Revision of Acartophthalmites Hennig and Clusiomites Gen. Nov. (Diptera)

The Eocene Baltic amber fossil flies of the genus Acartophthalmites Hennig, 1965 (Diptera: Acalyptratae) are revised. Seven species are recognized and described or redescribed. Five species, A. crassipes sp. nov., A. luridus sp. nov., A. rugosus sp. nov., A. tertiaria Hennig, 1965 (type species) and A. willii Pérez-de la Fuente, Hoffeins et Roháček, 2018 are retained in Acartophthalmites while Clusiomites gen. nov. is described for two other species, C. clusioides (Roháček, 2016) comb. nov. (type species) and C. ornatus sp. nov. Relationships of these fossil taxa are discussed and, because they cannot be confidently placed in any known family of Diptera, a new family, Clusiomitidae, is established for them. Clusiomitidae is recognized as a family of Opomyzoidea, probably most closely allied to Clusiidae. These results again confirmed that the diversity of acalyptrate flies was very high in the Mid-late Eocene amber forest.

Fossil Darwin wasps (Hymenoptera: Ichneumonidae) from Baltic amber

Seven subfamilies of Darwin wasps (Hymenoptera, Ichneumonidae), Banchinae, Cryptinae, Orthocentrinae, Pherhombinae, Stilbopinae, Townesitinae and Tryphoninae in Baltic amber are reviewed. Two species, Rovenosa alexrasnitsyni Manukyan, sp. nov. and R. khalaimi Manukyan, sp. nov. (Stilbopinae) are described as new to science. The male of Rovenosa rasnitsyni Khalaim, 2011 is recorded and described for the first time. The discovery of the puparium of an aphidophagous syrphid fly (Diptera: Syrphidae) with an emergence hole characteristic for Diplazontinae is the first fossil evidence of the subfamily. The strong bias in composition of the Ichneumonidae fauna in Baltic amber is noted. The presence of certain taxa in amber is suggested to be primarily due to specific properties of the pine resin, and only secondarily due to their occurrence in the “amber” forest.

In search for the unlikely: Leaf-mining caterpillars (Gracillariidae, Lepidoptera) from Upper Cretaceous and Eocene ambers

Fossil leaf-mining caterpillars from amber are firstly described as the new species Phyllocnistis cretacea from Upper Cretaceous Myanmar amber and Phyllonorycter inopinata from Eocene Baltic amber. Both show typical traits of leaf-miners, and specifically, of later instars of caterpillars of their respective genera. The findings give further evidence for these being quite old and conservative genera of Gracillariidae. These are basal Ditrysia which retained the larval feeding and mining live mode. The findings also represent direct fossil evidence of individual stages of hypermetamorphosis known from extant Gracillariidae. The finds from the Upper Cretaceous and their putative identifications give direct evidence for a minimal geological age for the genus Phyllocnistis (Phyllocnistinae) and, by indirect conclusion based on their divergence, also for the genus Phyllonorycter in a sister clade (Lithocolletinae). It also predates mining habit closer to the time of radiation of their angiospermous host plants.

A second fossil species of the enigmatic rove beetle genus Charhyphus in Eocene Baltic amber, with implications on the morphology of the female genitalia (Coleoptera: Staphylinidae: Phloeocharinae)

ABSTRACT Phloeocharinae is a small and likely non-monophyletic subfamily of rove beetles. The enigmatic genus Charhyphus Sharp, 1887 has long been placed in Phloeocharinae, whereas recent studies have found it to be phylogenetically very distant from the core members of this subfamily, suggesting the possibility that it actually deserves its own separate subfamily status. So far, the sole definitive fossil record for Charhyphus is known based on a single male from Eocene Baltic amber as represented by †Charhyphus balticus Shavrin, 2020. Here, we describe and illustrate another new Charhyphus species, †Charhyphus serratus sp. nov. Yamamoto & Shavrin, from Baltic amber based on a well-preserved female fossil. Considering the general proportions of the body and the head, this new species is most similar to †C. balticus. The new species differs from all known species by the development of strong serration of the lateral edges of the pronotum and features of the shape of the apical margin of the mesoventrite. By using X-ray micro-computed tomography, we succeeded in visualising not only the general habitus but also each individual body part, recovering a previously undocumented sclerite on the female internal genital segments in the genus. Morphological features of extinct and extant species of Charhyphus are briefly discussed. Figures of all extant Charhyphus species and a key for the genus are also provided. Our study is important for considering possible higher palaeodiversity, more common occurrence, and palaeobiogeography of Charhyphus.

Recent discoveries of new Elephantomyia (Diptera, Limoniidae) fossils in Baltic amber

New data on the genus Elephantomyia (Diptera: Limoniidae) from Baltic amber are presented. A new subgenus Hoffeinsonia subgen. nov. is established with one new species: Elephantomyia (Hoffeinsonia) prima sp. nov. The new subgenus is characterized by a wing at most 2.5 × as long as it is wide without a darker pattern along the veins Sc and R1, elongate Sc, straight vein R1, sharp half of vein R2+3+4 sharply arched to the upper edge of the wing, short, wide, trapezoidal d-cell and oval pterostigma. The fossil subgenus Hoffeinsonia subgen. nov. shares features with the extant subgenera Elephantomyodes and Elephantomyia. One other extinct species of Elephantomyia was discovered and described herein as E. (s. str.) christelae sp. nov. Such features as a very elongate vein R2+3+4, 2.5 × as long as the Rs easily allowing this new species to be distinguished from the other fossil representatives of the genus Elephantomyia. The taxonomic decision on Elephantomyia grata as a species placed in nominative subgenus is provided. A list and key of fossil species of Elephantomyia are given. The morphological pattern of the genus is discussed in relation to the adaptation to a specific food spectrum, coevolution with Angiospermae of the representative genus Helius known since Cretaceous and closely related to this genus representatives of the much younger genus Elephantomyia.