The natural history of fossil insect herbivory

Insect herbivory is the fundamental component of the plant-insect associations (PIAs). The origin and evolution of insect herbivory in terrestrial ecosystems reflects major changes in the paleoenvironment such as climate change, which plays an important role on the evolution of plant-insect interactions, and the ecological behavior of past (and modern) insects. We classified the research history of insect herbivory into the initial exploration, development and prosperity, three stages. The specific difference between the plant chemical damage and physical damage of insect herbivory was introduced. The fossil evidence and FFG-DT system of insect herbivory were illustrated. The major developments for the origin and evolution of insect herbivory on palaeofloras were: ① Silurian-Devonian (444~359 Ma), the origin of herbivory; ② Carboniferous (359~299 Ma), the expansion of herbivory; ③ Permian (299~252 Ma) the colonization of herbivory with new habitats; ④ Triassic (252~201 Ma) the rediversification of herbivory, with plants and insects recovery; ⑤ Jurassic (201~145 Ma) the elevation of herbivory; ⑥ Cretaceous (145~66 Ma), terrestrial evolution of gymnosperms transit to angiosperms with obviously diverse insect herbivory; at the end-Cretaceous, insect herbivory levels declined with unbalanced damage types in herbivory; ⑦ Paleogene (66~23 Ma), herbivory rehabilitation from unbalance; ⑧ Neogene (23~2.6 Ma) the herbivory basically modernized. The main factors that affecting insect herbivory, including climate environment, insect and plant diversity, insect mouthpart structures, plant component community and microorganisms. The problems existing in current insect herbivory research, which includes unifying the research system and methods, and filling the missing links of the herbivory during the past ca.430 million years, are need to be consider and solve carefully. © 2022, Science Press. All right reserved.