Xiumei Lu

New long-proboscid lacewings of the mid-Cretaceous provide insights into ancient plant-pollinator interactions

Many insects with long-proboscid mouthparts are among the pollinators of seed plants. Several cases of the long-proboscid pollination mode are known between fossil insects (e.g., true flies, scorpionflies, and lacewings) and various extinct gymnosperm lineages, beginning in the Early Permian and increasing during the Middle Jurassic to Early Cretaceous. However, details on the morphology of lacewing proboscides and the relevant pollination habit are largely lacking. Here we report on three lacewing species that belong to two new genera and a described genus from mid-Cretaceous (Albian-Cenomanian) amber of Myanmar. All these species possess relatively long proboscides, which are considered to be modified from maxillary and labial elements, probably functioning as a temporary siphon for feeding on nectar. Remarkably, these proboscides range from 0.4–1.0 mm in length and are attributed to the most diminutive ones among the contemporary long-proboscid insect pollinators. Further, they clearly differ from other long-proboscid lacewings which have a much longer siphon. The phylogenetic analysis indicates that these Burmese long-proboscid lacewings belong to the superfamily Psychopsoidea but cannot be placed into any known family. The present findings represent the first description of the mouthparts of long-proboscid lacewings preserved in amber and highlight the evolutionary diversification of the ancient plant-pollinator interactions.

New genera and species of the minute snakeflies (Raphidioptera: Mesoraphidiidae: Nanoraphidiini) from the mid Cretaceous of Myanmar

The Mesozoic amber snakeflies are important for understanding the early evolution and phylogeny of Raphidioptera. Here we describe three new genera and four new species of the extinct family Mesoraphidiidae from the mid Cretaceous amber of northern Myanmar, including Dolichoraphidia aspoecki gen. et sp. nov., Dolichoraphidia engeli gen. et sp. nov., Rhynchoraphidia burmana gen. et sp. nov., and Burmoraphidia reni gen. et sp. nov. All these species, together with the previously described species (i.e., Nanoraphidia electroburmica Engel, 2002) from Burmese amber, belong to the mesoraphidiid tribe Nanoraphidiini based on the minute body-size and the swollen tibiae. A key to all species of Nanoraphidiini is provided. A brief discussion on the genital morphology of Mesoraphidiidae is also given.

The first green lacewing (Insecta: Neuroptera: Chrysopidae) from the mid-Cretaceous amber of Myanmar

The lacewing family Chrysopidae is here reported from the mid-Cretaceous amber of Myanmar for the first time. A new genus and species, Parabaisochrysa xingkei gen. et sp. nov., is described. The new genus belongs to the extinct subfamily Limaiinae and is characterized by the presence of three gradate series of crossveins in both fore- and hind wing, and by the MP1 coalescent with RP+MA in the hind wing.

Taxonomic notes on Cretarophalis patrickmuelleri Wichard, 2017 (Insecta: Neuroptera: Nevrorthidae) from the mid-Cretaceous of Myanmar, and its phylogenetic significance

Nevrorthidae is a family of Neuroptera with low species diversity, disjunct geographic distributions, and a controversial phylogenetic status. Previous fossil records of the family are from the Eocene except for the recently described species Cretarophalis patrickmuelleri Wichard, 2017 from mid-Cretaceous Burmese amber, following earlier records of an undescribed species. However, such a significant finding of this family from Mesozoic was originally presented only with a preliminary description. Here we re-describe the species based on exquisitely preserved materials from mid-Cretaceous Burmese amber that provides for a much more detailed description, in particular of the hindwing, female genitalia, and larval head. Furthermore, distinctive morphological characters of C. patrickmuelleri with significant phylogenetic relevance are discussed. The general morphology, particularly that of the larva, has changed little between the Mesozoic and Cenozoic, and it reflects an evolutionary stasis that might correspond to their aquatic larval life-style. The present finding also supports the relictual nature of the modern nevrorthids.

High niche diversity in Mesozoic pollinating lacewings

Niche diversity of pollinating insects plays a vital role in maintaining extant terrestrial ecosystems. A key dimension of pollination niches refers to the insect proboscis length that commonly matches the floral tube length. Here we describe new kalligrammatid lacewings (an iconic Mesozoic pollinating insect lineage) from late Cretaceous Burmese amber and Mesozoic sediments in China. Kalligrammatids display complex configurations of elongate mouthpart elements consisting of well-developed maxillae, labium and their palps. The mouthpart lengths vary among species, from 0.6 to 18.0 mm, suggesting corresponding variability in the floral tube lengths of Mesozoic plants. With the diversification of pollinating habits, the kalligrammatids presented highly divergent traits related to chemical communication and defence mechanisms. Together with other Mesozoic long-proboscid insects, these fossils not only reveal the high niche diversity of Mesozoic pollinating insects but also highlight the diversity of Mesozoic pollinator-dependent plants prior to the rise of angiosperms.Kalligrammatid lacewings were among the largest Mesozoic insects. Here, Liu et al. present an assemblage of Mesozoic kalligrammatid lacewings from amber and compression fossils, highlighting diversity in traits associated with pollination, chemical communication and defense against predators.

First description of female of Haplosialodes liui Huang et al. , 2016 (Megaloptera: Sialidae) from Cretaceous Burmese amber

A female of the alderfly species, Haplosialodes liui Huang et al., 2016, from the mid-Cretaceous Burmese amber is described for the first time. Systematic position of the genus Haplosialodes Huang et al., 2016 is briefly discussed.

Phylogenetic position of Corydasialidae (Insecta: Neuropterida) revisited based on a significant new fossil in Cretaceous amber of Myanmar

The family Corydasialidae, currently comprising two monotypic genera from the Eocene, is one of the few groups with undetermined ordinal placement in Neuropterida, although it was previously considered to be an intermediate form between Corydalidae and Sialidae in Megaloptera. Here we describe a new taxon of Corydasialidae – Megalopteroneura chenxingi gen. et sp. nov. – based on an exquisitely preserved specimen in mid-Cretaceous (Albian–Cenomanian) amber of Myanmar. The new corydasialid in general resembles the genus Cratochrysa Martins-Neto, 1994 (Neuroptera: familia incertae sedis) from the Early Cretaceous Crato Formation of Brazil. In light of the new fossil evidence, Corydasialidae is herein transferred from Megaloptera to Neuroptera based on sharing the following autapomorphies of the latter order: orthognathous head, absence of gula, distinctly enlarged prementum of labium, and short forewing ScA terminating on ScP. Male genitalia of M. chenxingi gen. et sp. nov. are superficially Raphidioptera-like, with well-developed male gonocoxites and gonapophyses 9 but lacking rosette of trichobothria on ectoprocts. However, male genital characters of the new corydasialid differ fundamentally from Raphidioptera in the separation of tergum and sternum 9, fusion between tergum 9 and ectoprocts, and fusion between sterna 8 and 9. These genital features, together with some wing characters, suggest a possible close relationship between Corydasialidae and Chrysopidae or Mesochrysopidae. The new corydasialid fossil, representing the first extinct lacewing family with completely preserved male genitalia, provides insight into the comparative morphology of genital sclerites in Neuropterida, and further elucidates the early evolution of lacewings. http://zoobank.org/urn:lsid:zoobank.org:pub:FD949294-59E3-455E-AABA-3E10D9B582D6