The first xiphydriid wood wasp in Cretaceous amber (Hymenoptera: Xiphydriidae) and a potential association with Cycadales

A new genus and species of fossil wood wasp is described and figured from mid-Cretaceous Kachin amber, representing the first occurrence of the family Xiphydriidae in the fossil record. Paraxiphydria resinata gen. et sp. nov. exhibits typical apomorphies of the family including a generally cylindrical body, elongate neck and dome-shaped head. Nonetheless, owing to a unique combination of traits including features hitherto unknown among species of the family, the genus is classified within a separate subfamily, Paraxiphydriinae subfam. nov. A key is presented to the suprageneric groups of Xiphydriidae. The newly described species is the first fossil xiphydriid wood wasp, extends the occurrence of Xiphydriidae into the mid-Cretaceous and adds to the known diversity of features in the family. Lastly, the simplification of wing venation and hypotheses of host-plant affiliations of early xiphydriids are discussed. We evaluate pollen associated with the wasp, assign it to the genus Cycadopites and conclude that an affiliation to the Cycadales is most likely. Article and nomenclatural acts are registered in ZooBank (http://zoobank.org/, last access: 15 December 2021), with the following life science identifier (LSID) (reference): urn:lsid:zoobank.org:pub:DA80920E-E94B-4A8E-A817-077FA7BD7D69.

Discovery of a new symphytan wasp in the mid-Cretaceous Kachin amber (Hymenoptera, Syspastoxyelidae)

The mid-Cretaceous Burmese amber from Kachin State of northern Myanmar provides a scanty but rather diverse fauna of sawflies. Herein Grandixyela rasnitsyni gen. et sp. nov. is described and illustrated on the basis of a well-preserved male specimen from Myanmar amber. The new fossil genus and species is characterized by wing venation and body characters, such as 15-segmented antenna with the first flagellomere distinctly shorter than the remaining, pterostigma narrow and completely sclerotized, 1-RS distinct (not dot-like), RS distal of 2r-rs gently S-shaped, ending to pterostigma beyond its apex for a short distance. A checklist and a review of known syspastoxyelid species are discussed. Additionally, our findings not only provide important morphological characters, especially the well-preserved details of the venation and genitalia, but also broaden new data on the Cretaceous diversity of symphytan wasps and further extend the records of syspastoxyelids to six genera and seven species.

A new genus and species of the aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) from the Eocene Sakhalinian amber

The new fossil genus and species, Sakhalinoctonus alexrasnitsyni Davidian, gen. et sp. nov., of hymenopteran parasitoids of aphids from the subfamily Aphidiinae (Braconidae) is described from the Middle Eocene Sakhalinian amber. This new genus is similar with the extinct Protacanthoides Mackauer, 1961 and Promonoctonia Starý, 1973 as well as with the extant Calaphidius Mackauer, 1961, Indaphidius Starý, 1979, Aclitus Foerster, 1862 and Archaphidus Starý & Sсhlinger, 1967, and differs from them by the small number of antennal segments, details of wing venation and propodeum areolation, the shape and pubescence of the ovipositor sheaths.

Past ecosystems drive the evolution of the early diverged Symphyta (Hymenoptera: Xyelidae) since the earliest Eocene

Paleoxyela nearctica gen. et sp. nov., is described from the upper Eocene of Florissant Formation in Colorado. We placed Paleoxyela gen. nov. in the subfamily Macroxyelinae and the tribe Macroxyelini based on the numerous wing venation characters visible on the specimen. Proxyelia pankowskii gen. et sp. nov. is described from the lower Eocene Fossil Lake deposits of the Green River Formation in Wyoming. We placed Proxyelia gen. nov. in the subfamily Macroxyelinae and the tribe Xyeleciini based on the numerous wing venation characters visible on the specimen. These new records of the family Xyelidae are of particular importance to better understand the past diversity of the clade and propose hypotheses about their diversification. Extant Xyelidae inhabit temperate Northern Hemisphere forests, and most of their larvae feed on conifers, which may explain why they are relatively poorly diversified compared to the other symphytan families. We suggest that the global decline in conifers and the reduced diversity of extant host trees partly explain the diversity of extant Xyelidae. We correlate the biome repartition during the Eocene to that of the extant xyelid.

Morphology of the oldest fossil subfamily of Limoniidae (Diptera, Architipulinae) in the light of exceptionally preserved Mesozoic material

Based on known fossil evidence the extinct subfamily Architipulinae is considered to be the oldest evolutionary group of the Limoniidae, the largest family within the infraorder Tipulomorpha. The morphology of this subfamily, which includes 11 genera, has so far been based mainly on wing venation. New well-preserved representatives of the genus Cretolimonia Kalugina, 1986 were recovered from the Jurassic/Cretaceous boundary of Shevia and Daya, Transbaikalia, as well as from mid-Cretaceous amber from Kachin, Myanmar. This new material enriches our knowledge of the subfamily Architipulinae and of the genus Cretolimonia, and allows us to ascertain the detailed morphological structure of the female copulatory apparatus with spermathecae and the structure of the male hypopygium. The combination of detailed impression fossils with a specimen preserved three-dimensionally in resin has permitted study of the morphology of this Mesozoic fly genus almost to the level of modern genera. The paper includes descriptions of four new species of Cretolimonia: C. lukashevichae sp. nov., C. pseudojurassica sp. nov., C. dayana sp. nov. from sedimentary rocks, and C. mikolajczyki sp. nov. from Myanmar amber, supported with a key to all known species.

Ovipositor and mouthparts in a fossil insect support a novel ecological role for early orthopterans in 300 million years old forests

A high portion of the earliest known insect fauna is composed of the so-called ‘lobeattid insects’, whose systematic affinities and role as foliage feeders remain debated. We investigated hundreds of samples of a new lobeattid species from the Xiaheyan locality using a combination of photographic techniques, including reflectance transforming imaging, geometric morphometrics, and biomechanics to document its morphology, and infer its phylogenetic position and ecological role. Ctenoptilus frequens sp. nov. possessed a sword-shaped ovipositor with valves interlocked by two ball-and-socket mechanisms, lacked jumping hind-legs, and certain wing venation features. This combination of characters unambiguously supports lobeattids as stem relatives of all living Orthoptera (crickets, grasshoppers, katydids). Given the herein presented and other remains, it follows that this group experienced an early diversification and, additionally, occurred in high individual numbers. The ovipositor shape indicates that ground was the preferred substrate for eggs. Visible mouthparts made it possible to assess the efficiency of the mandibular food uptake system in comparison to a wide array of extant species. The new species was likely omnivorous which explains the paucity of external damage on contemporaneous plant foliage.

The termite genus Glyptotermes (Isoptera: Kalotermitidae) in Miocene amber from Ethiopia

A new species of drywood termite (Isoptera: Kalotermitidae) is described from a nearly complete alate specimen preserved in early Miocene Ethiopian amber. Glyptotermes abyssinicus new species is distinguished by its U-shaped head with 12-segmented antennae, the ocelli separated from the eye margin, the right mandible with an obtuse angle between the apical and first marginal teeth, the left mandible with an obtuse angle between the apical and first + second marginal teeth, and the wing venation. This is the first termite reported from Ethiopian amber, and the fourth Miocene species of the extant genus Glyptotermes Froggatt, 1897, together with species previously described from diatomites of China and amber from the Dominican Republic. As the oldest report of the genus known from Africa, G. abyssinicus n. sp. constitutes an interesting new record for the biogeographical history of the kalotermitid lineage. UUID: http://zoobank.org/7670b045-fb31-4809-8116-4d14c4dd275b

An unusual elateroid lineage from mid-Cretaceous Burmese amber (Coleoptera: Elateroidea)

We here report a new elateroid, Anoeuma lawrencei Li, Kundrata and Cai gen. et sp. nov., from mid-Cretaceous Burmese amber. Though superficially similar to some soft-bodied archostematans, Anoeuma could be firmly placed in the polyphagan superfamily Elateroidea based on the hind wing venation. Detailed morphological comparisons between extant elateroids and the Cretaceous fossils suggest that the unique character combination does not fit with confidence into any existing soft-bodied elateroid group, although some characters indicate possible relationships between Anoeuma and Omalisinae. Our discovery of this new lineage further demonstrates the past diversity and morphological disparity of soft-bodied elateroids.

Lepidoptera demonstrate the relevance of Murray’s Law to circulatory systems with tidal flow

Background Murray’s Law, which describes the branching architecture of bifurcating tubes, predicts the morphology of vessels in many amniotes and plants. Here, we use insects to explore the universality of Murray’s Law and to evaluate its predictive power for the wing venation of Lepidoptera, one of the most diverse insect orders. Lepidoptera are particularly relevant to the universality of Murray’s Law because their wing veins have tidal, or oscillatory, flow of air and hemolymph. We examined over one thousand wings representing 667 species of Lepidoptera. Results We found that veins with a diameter above approximately 50 microns conform to Murray’s Law, with veins below 50 microns in diameter becoming less and less likely to conform to Murray’s Law as they narrow. The minute veins that are most likely to deviate from Murray’s Law are also the most likely to have atrophied, which prevents efficient fluid transport regardless of branching architecture. However, the veins of many taxa continue to branch distally to the areas where they atrophied, and these too conform to Murray’s Law at larger diameters (e.g., Sesiidae). Conclusions This finding suggests that conformity to Murray’s Law in larger taxa may reflect requirements for structural support as much as fluid transport, or may indicate that selective pressures for fluid transport are stronger during the pupal stage—during wing development prior to vein atrophy—than the adult stage. Our results increase the taxonomic scope of Murray’s Law and provide greater clarity about the relevance of body size.