Time and again, over hundreds of millions of years, environmental disturbances have caused mass extinctions of animals ranging from reptiles to corals. The anthropogenic loss of species diversity happening now is often discussed as the ‘sixth mass extinction' in light of the ‘Big Five' mass extinctions in the fossil record. But insects, whose taxonomic diversity now appears to be threatened by human activity, have a unique extinction history. Prehistoric losses of insect diversity at the levels of order and family appear to have been driven by competition among insect lineages, with biotic replacement ensuring minimal net losses in taxonomic diversity. The end-Permian extinction, the ‘mother of mass extinctions' in the seas, was more of a faunal turnover than a mass extinction for insects. Insects' current biotic crisis has been measured in terms of the loss of abundance and biomass (rather than the loss of species, genera, or families) and these are essentially impossible to measure in the fossil record. However, should the ongoing loss of insect abundance and biomass cause the demise of many insect families, the current extinction event may well be the first sudden loss of higher-level insect diversity in our planet's history. This is not insects’ sixth mass extinction—in fact, it may become their first.

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Are Insects Heading Toward Their First Mass Extinction? Distinguishing Turnover From Crises in Their Fossil Record

Courtship behaviours, frequent among modern insects, have left extremely rare fossil traces. None are known previously for fossil odonatans. Fossil traces of such behaviours are better known among the vertebrates, e.g. the hypertelic antlers of the Pleistocene giant deer Megaloceros giganteus. Here we describe spectacular extremely expanded, pod-like tibiae in males of a platycnemidid damselfly from mid-Cretaceous Burmese amber. Such structures in modern damselflies, help to fend off other suitors as well as attract mating females, increasing the chances of successful mating. Modern Platycnemidinae and Chlorocyphidae convergently acquired similar but less developed structures. The new findings provide suggestive evidence of damselfly courtship behaviour as far back as the mid-Cretaceous. These data show an unexpected morphological disparity in dancing damselfly leg structure, and shed new light on mechanisms of sexual selection involving intra- and intersex reproductive competition during the Cretaceous.

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Extreme adaptations for probable visual courtship behaviour in a Cretaceous dancing damselfly.

Deep learning as a tool for ecology and evolution

Two new species of Jurassic Chrysopidae are described: Mesypochrysa sinica sp. nov. (Limaiinae) from the Middle–Upper Jurassic boundary interval of Daohugou (China) and Baisochrysa pumila sp. nov. (Limaiinae) from the Upper Jurassic of Karatau (Kazakhstan). Mesypochrysa intermedia Panfilov, 1980, previously known from Karatau, is recorded from Daohugou. Mesypochrysa sinica sp. nov. and M. cf. intermedia from Daohugou are considered to be the earliest known, unquestionable green lacewings. Lembochrysa Ren and Guo, 1996 is synonymized with Mesypochrysa Martynov, 1927. Mesypochrysa makarkini Nel et al., 2005 is synonymized with M. intermedia, and the size range of their forewings is discussed. Male and female terminalia of the Mesozoic green lacewings are described for the first time. The diversification of ants is considered a possible cause of the extinction of Limaiinae during the early Eocene.

Early green lacewings (Insecta: Neuroptera: Chrysopidae) from the Jurassic of China and Kazakhstan

The Mesozoic is a key era for the rise of the modern insect fauna. Among the most important evolutionary events in Mesozoic insects are the radiation of holometabolous insects, the origin of eusocial and parasitoid insects, diversification of pollinating insects, and development of advanced mimicry and camouflage. These events are closely associated with the diversification of insect ecological behaviors and colonization of new ecospaces. At the same time, insects had evolved more complex and closer ecological associations with various plants and animals. Mesozoic insects played a key and underappreciated ecological role in reconstructing and maintaining terrestrial ecosystems. A greater understanding of the history of insects may help to mitigate future changes in insect diversity and abundance. 

Ecological radiations of insects in the Mesozoic.

New Ephialtitidae (Insecta: Hymenoptera) from the Jurassic Daohugou Beds of Inner Mongolia, China

Widespread mimicry and camouflage among mid-Cretaceous insects

Re-description and systematics of Paraulacus sinicus Ping, 1928 (Insecta, Hymenoptera)

﻿Abstract Commelinadanxiaensis (Commelinaceae), a remarkable new species from Mount Danxia, Guangdong Province, China, is described and illustrated. This species is similar to C.communis in inflorescences and flowers but readily distinguishable in its nearly erect stems, larger flowers, and different petal colouration.

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Ming Ding

Papers

New Ephialtitidae (Insecta: Hymenoptera) from the Jurassic Daohugou Beds of Inner Mongolia, China

Widespread mimicry and camouflage among mid-Cretaceous insects

Re-description and systematics of Paraulacus sinicus Ping, 1928 (Insecta, Hymenoptera)

Commelinadanxiaensis (Commelinaceae), a new species from Guangdong, China

Ming Ding

Papers

New Ephialtitidae (Insecta: Hymenoptera) from the Jurassic Daohugou Beds of Inner Mongolia, China

Widespread mimicry and camouflage among mid-Cretaceous insects

Re-description and systematics of Paraulacus sinicus Ping, 1928 (Insecta, Hymenoptera)

﻿Commelinadanxiaensis (Commelinaceae), a new species from Guangdong, China

Commelinadanxiaensis (Commelinaceae), a new species from Guangdong, China