Yunyun Zhao

Ancient pinnate leaf mimesis among lacewings

Insects have evolved diverse methods of predator avoidance, many of which implicate complex adaptations of their wings (e.g., Phylliidae, Nymphalidae, Notodontidae). Among these, angiosperm leaf mimicry is one of the most dramatic, although the historical origins of such modifications are unclear owing to a dearth of paleontological records. Here, we report evidence of pinnate leaf mimesis in two lacewings (Neuroptera): Bellinympha filicifolia Y. Wang, Ren, Liu & Engel gen. et sp. nov. and Bellinympha dancei Y. Wang, Ren, Shih & Engel, sp. nov., from the Middle Jurassic, representing a 165-million-year-old specialization between insects and contemporaneous gymnosperms of the Cycadales or Bennettitales. Furthermore, such lacewings demonstrate a preangiosperm origin for leaf mimesis, revealing a lost evolutionary scenario of interactions between insects and gymnosperms. The current fossil record suggests that this enigmatic lineage became extinct during the Early Cretaceous, apparently closely correlated with the decline of Cycadales and Bennettitales at that time, and perhaps owing to the changing floral environment resulted from the rise of flowering plants.

Jurassic mimicry between a hangingfly and a ginkgo from China

A near-perfect mimetic association between a mecopteran insect species and a ginkgoalean plant species from the late Middle Jurassic of northeastern China recently has been discovered. The association stems from a case of mixed identity between a particular plant and an insect in the laboratory and the field. This confusion is explained as a case of leaf mimesis, wherein the appearance of the multilobed leaf of Yimaia capituliformis (the ginkgoalean model) was accurately replicated by the wings and abdomen of the cimbrophlebiid Juracimbrophlebia ginkgofolia (the hangingfly mimic). Our results suggest that hangingflies developed leaf mimesis either as an antipredator avoidance device or possibly as a predatory strategy to provide an antiherbivore function for its plant hosts, thus gaining mutual benefit for both the hangingfly and the ginkgo species. This documentation of mimesis is a rare occasion whereby exquisitely preserved, co-occurring fossils occupy a narrow spatiotemporal window that reveal likely reciprocal mechanisms which plants and insects provide mutual defensive support during their preangiospermous evolutionary histories.

Blood-Feeding True Bugs in the Early Cretaceous

Blood-feeding insects, as vectors of disease for humans and livestock alike, have garnered significant interest, but our understanding of their early evolution is hindered by the scarcity of available material and the difficulty in distinguishing early hematophages from non-blood-feeding relatives. Here, we report a new family of true bugs including two new genera and species from the Early Cretaceous Yixian Formation in Northeastern China. By utilizing geochemical methods for determining their diets and combining morphological and taphonomic data, we demonstrate that these new species represent the earliest evidence of blood feeding among true bugs, extending the geological record of such lineages by approximately 30 million years. Remarkably, one of the bugs appears to have perished immediately following a blood meal, which may have been from coexisting mammals, birds, or avian-related dinosaurs. These records expand the phylogenetic and ecological diversity of blood-feeding insects in the Early Cretaceous, enriching our knowledge of paleoecological associations in these ancient environments.

Morphology, Phylogeny, Evolution, and Dispersal of Pelecinid Wasps (Hymenoptera: Pelecinidae) Over 165 Million Years

ABSTRACT Large female pelecinid wasps, elegant and beautiful with uniquely elongated metasoma, are found only in North, Central, and South America. These distinctive wasps are “living fossils” in a relict family of Pelecinidae. Recent discoveries of well preserved pelecinid fossils from the Middle Jurassic (165 Mya) to the Early Cretaceous (125 Mya) of northeastern China, of which Megapelecinus changi gen. et sp. nov. and Megapelecinus nashi, sp. nov. are described herein, provide strong evidence for morphological changes and evolution of pelecinids, such as body size, antennae and wing venation, over the past ≈165 million years. A phylogenetic analysis using 22 morphological characters, 12 extinct pelecinid taxa and one extant pelecinid taxon at the generic level suggests that Megapelecinus gen. nov. is the most basal pelecinid, whereas Cathaypelecinus Shih, Liu et Ren 2009, Archaeopelecinus Shih, Liu et Ren 2009, and Iscopinus Kozlov, 1974 forming a basal clade. Natural selection is demonstrated in pelecinids by the preference of larger female body size offering potentially better ovipositing capability and more efficient forewing venation with an X pattern providing potentially stronger wing structure and better flight performance for large-sized pelecinids. Furthermore, temporal and spatial analyses indicate that the most parsimonious hypothesis is that pelecinid might have originated from Northeastern China, spread to Central and Eastern Asia, and then dispersed to Americas.

Transitional fossil earwigs - a missing link in Dermaptera evolution

BackgroundThe Dermaptera belongs to a group of winged insects of uncertain relationship within Polyneoptera, which has expanded anal region and adds numerous anal veins in the hind wing. Evolutional history and origin of Dermaptera have been in contention.ResultsIn this paper, we report two new fossil earwigs in a new family of Bellodermatidae fam. nov. The fossils were collected from the Jiulongshan Formation (Middle Jurassic) in Inner Mongolia, northeast China. This new family, characterized by an unexpected combination of primitive and derived characters, is bridging the missing link between suborders of Archidermaptera and Eodermaptera. Phylogenetic analyses support the new family to be a new clade at the base of previously defined Eodermaptera and to be a stem group of (Eodermaptera+Neodermaptera).ConclusionEvolutional history and origin of Dermaptera have been in contention, with dramatically different viewpoints by contemporary authors. It is suggested that the oldest Dermaptera might possibly be traced back to the Late Triassic-Early Jurassic and they had divided into Archidermaptera and (Eodermaptera+Neodermaptera) in the Middle Jurassic.

New Earwigs in Protodiplatyidae (Insecta: Dermaptera) from the Middle Jurassic Jiulongshan Formation of Northeastern China

Two new genera, each with a new species, Perissoderma triangulum gen. et sp. nov. and Abrderma gracilentum gen. et sp. nov., of the family Protodiplatyidae are described from the latest Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. They are the first records of Protodiplatyidae from the latest Middle Jurassic Daohugou locality. Both new genera are assigned to Protodiplatyidae based mainly on diagnostic characters of antennae, pronotum, tegmina, tarsi and the distinct long, slender, multi-segmented cerci. We summarize the distributions and ages of all described fossil Archidermaptera and infer that the Dermaptera might have originated in Eurasia and started their diversification and migration to a worldwide distribution. The new taxon of Abrderma gracilentum gen. et sp. nov. provides one more example of an early earwig with well-preserved pentamerous tarsi on the hind leg.