The extinct Baltic amber genus Propelma Trjapitzin,a valid genus of Neanastatinae (Hymenoptera,?Eupelmidae)

The extinct Eocene Baltic amber genus Propelma Trjapitzin 1963 is removed from synonymy under Eupelmus Dalman 1820 (Hymenoptera, Eupelmidae, Eupelminae) and treated as a valid genus within Neanastatinae Kalina 1984 based on examination of the holotype female of Propelma rohdendorfi Trjapitzin. Propelma rohdendorfi is redescribed, illustrated by photomacrographs, and compared to other described extant and extinct genera of Neanastatinae. Taxonomic, morphological and geological diversity of Neanastatinae relative to Eupelminae and Calosotinae is also discussed relative to potential age of the subfamily.     

Species of two paleoendemic sap beetle genera of the Tribe Nitidulini (Nitidulidae: Coleoptera) from the Baltic and Dominican amber

Omositoidea gigantea Schaufuss, 1892 is redescribed; O. pubescens sp. nov. from the Baltic amber, Palaeometopia dominicana gen. et sp. nov. and P. colorata gen. et sp. nov. from the Dominican amber are described. The taxonomic position of the two genera and their probable bionomy are discussed.     

Insect outbreaks produce distinctive carbon isotope signatures in defensive resins and fossiliferous ambers

Despite centuries of research addressing amber and its various inclusions, relatively little is known about the specific events having stimulated the production of geologically relevant volumes of plant resin, ultimately yielding amber deposits. Although numerous hypotheses have invoked the role of insects, to date these have proven difficult to test. Here, we use the current mountain pine beetle outbreak in western Canada as an analogy for the effects of infestation on the stable isotopic composition of carbon in resins. We show that infestation results in a rapid (approx. 1 year) (13)C enrichment of fresh lodgepole pine resins, in a pattern directly comparable with that observed in resins collected from uninfested trees subjected to water stress. Furthermore, resin isotopic values are shown to track both the progression of infestation and instances of recovery. These findings can be extended to fossil resins, including Miocene amber from the Dominican Republic and Late Cretaceous New Jersey amber, revealing similar carbon-isotopic patterns between visually clean ambers and those associated with the attack of wood-boring insects. Plant exudate δ(13)C values constitute a sensitive monitor of ecological stress in both modern and ancient forest ecosystems, and provide considerable insight concerning the genesis of amber in the geological record.     

The first fossil spider cricket (Orthoptera: Gryllidae: Phalangopsinae): 20 million years of troglobiomorphosis or exaptation in the dark?

A new spider cricket (Orthoptera: Gryllidae: Phalangopsinae) is described from an adult female preserved in Early Miocene (Burdigalian) amber from the Dominican Republic. Araneagryllus dylani gen. et sp. nov. represents the first fossil record of Phalangopsinae, and is assigned to the tribe Luzarini, subtribe Amphiacustina stat. nov. A cladistic analysis of Amphiacustina places Araneagryllus gen. nov. within a clade comprising Arachnopsita, Leptopedetes, Longuripes, Mayagryllus, Nemoricantor, and Prolonguripes. This clade is the sister group to a clade comprising Amphiacusta, Cantrallia, and Noctivox. The results of this analysis suggest that: (1) the common ancestor of all Amphiacustina was epigean, and was likely to have been cavicolous and/or straminicolous; (2) strict troglobitism evolved twice within Amphiacustina, once in the lineage leading to Noctivox and again in the clade comprising Mayagryllus, Arachnopsita, Longuripes, and Prolonguripes; and (3) Prolonguripes is secondarily epigean, having reverted to life above ground. The occurrence of Araneagryllus gen. nov. in amber indicates that it was not troglobitic, but was instead more likely to have been straminicolous, living on the ground and foraging amongst leaf litter. Araneagryllus gen. nov. possesses a number of characters that are usually considered to be adaptive to a troglobitic life history, suggesting that many so‐called troglobiomorphies are not adaptations to life in caves, but are instead likely to have been exaptive. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 56–65.     

On the find of adult Micromalthus (Coleoptera, Micromalthidae) in Dominican amber

An adult of Micromalthus is discovered in amber for the first time. The species, from the Miocene Dominican amber, is described as M. anansi sp. nov., and is generally similar to Recent M. debilis, but differs in the longer legs and antennae. The Miocene species appears to be less fetalized than its modern counterpart.     

How long can insect species exist? Evidence from extant and fossil Micromalthus beetles (Insecta: Coleoptera)

Six new fossils of Micromalthus (Coleoptera: Archostemata) from Dominican amber are compared with extant and previously described fossil micromalthid beetles. The amber inclusions are well preserved and all important morphological features are visible. Taking into account the morphological variability of the extant species Micromalthus debilis LeConte, 1878 , it is not possible to find any morphological features that distinguish the fossils from the extant species. This also applies to the Dominican amber inclusion described as Micromalthus anasi Perkovsky, 2008, which therefore is considered a junior synonym of M. debilis. The lack of morphological change in M. debilis over time might possibly be explained by unusually stable environmental conditions, as this species occupies a very specialized ecological niche in decaying timber. A general survey of fossil insects indistinguishable from extant species is presented. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 300–311.