Insect herbivory from the late Permian Wangjiazhai plant assemblage of South China and its ecological implications

Different herbivorous insects can induce specific herbivory traces on foliage due to their distinct feeding habits and mouthparts. Fossil evidence of plant-insect associations allows to explore these interactions. The plant-insect interactions from the Wuchiapingian Wangjiazhai plant assemblage in southwestern China are analysed. Six hundred and twenty-one leaf fossils were collected, with 182 showing herbivory traces. Two hundred and fourteen occurrences attributed to 12 damage types (DTs) from three functional feeding groups (FFGs) were recognised: margin feeding, hole feeding and oviposition. Herbivorous insects fed on some plants, laid eggs on a few plants, and also used them as essential shelter. To further explore plant-insect interactions, a quantitative analysis was conducted based on the Wangjiazhai and nine other Permian plant assemblages. The DT abundance as well as its occurrences revealed external feeding (margin feeding and hole feeding) accounted for the highest proportion of all FFGs in these assemblages, suggesting there was a relatively high abundance of external feeding culprits in these ecosystems. Besides, broadleaved gigantopterid laminae were less than strap-shaped taeniopterid foliage in the Wangjiazhai assemblage, but the former had more herbivorized leaves and DT occurrences (based on presence-absence data). The result suggests herbivorous insects preferentially targeted broadleaved gigantopterids.