Insect herbivory on ferns from a midland Atlantic Rainforest locality, southern Brazil: implications for interpreting fossil plant–insect interaction

This work contains the results of fern–arthropod interactions from a midland Atlantic Rainforest locality and addresses the taphonomic, morphological and ecological implications of insect damage on ferns to interpret them on fossil plant assemblages. Six functional feeding groups – margin feeding, hole feeding, surface feeding, piercing and sucking, mining and galling – are present on the three fern species inhabiting the understory of an Araucaria Forest in the Atlantic Forest biome, southern Brazil. We recognised 19 damage types (DTs), including 14 arthropod-induced DTs, three of which are newly proposed herein. Five of the DTs found were first recorded on ferns. Of the DTs found, the proportion of guilds such as mining and galling shows a significant similarity with those of an upland locality. Products of arachnids and insect behaviour on ferns made up 25% of all fern–arthropod interactions in the midland locality, which included dead bodies and byproducts from processes of arthropod life cycle, which are unlikely to be preserved in the fossil record. This rate of arthropod products consists of significant evidence of interactions to unveil deep-time relationships between arthropods and plants. Lastly, leaf damage on living ferns is more frequent than those occurring in fossil plant assemblages.

本数据集收录了大西洋雨林内陆位点的蕨类与节肢动物相互作用研究结果，针对昆虫对蕨类造成的取食损伤开展埋藏学、形态学与生态学层面的分析，以此为基础对化石植物组合中的相关损伤痕迹进行解读。本次研究共识别出6类功能取食类群——叶缘取食、孔洞取食、表面取食、刺吸式取食、潜叶取食与造瘿取食，这些损伤痕迹出现在巴西南部大西洋森林生物群落中南洋杉林林下的3种蕨类植物上。本研究共确认19种损伤类型（Damage Types，DTs），其中14种为节肢动物诱导产生的损伤类型，另有3种为本文首次提出；本次发现的损伤类型中有5种为首次在蕨类植物上被记录。在所发现的损伤类型中，潜叶取食、造瘿取食等取食类群的占比，与某一高地位点的相关占比存在显著相似性。该内陆位点中，蛛形纲动物与昆虫在蕨类上的行为产物占所有蕨类-节肢动物相互作用记录的25%，此类产物包括节肢动物生命周期过程中产生的尸体与副产物，而这类物质通常难以在化石记录中保存下来。这类节肢动物产物的占比数据，为揭示节肢动物与植物间的深时演化关系提供了重要佐证。最后，现生蕨类叶片的损伤发生频率要高于化石植物组合中的相关损伤记录。