Plant–insect interactions in the Quaternary fossil record of the Azores Archipelago (Portugal)

Abstract

The fossil record of the Azores still lacks evidence of terrestrial invertebrates. Based on a study of the collections of Quaternary fossil plant imprints from the Azores, located in the depositories of public collections and also newly conducted field research, several samples of fossil leaves with traces of plant-animal interactions were found. These are evidence of marginal feeding (Phagophytichnus ekowskii) and anophionome mine (Cuniculonomus isp.). One specimen with traces of boring in fossil wood (Xylonichnus trypetus), previously only briefly mentioned in the literature, was also described in detail. In addition to a detailed description of the found traces, the present study also discusses the possible trace-makers, using a comparison with the recent phytophagous fauna in relation to the original vegetation of the Azores (that includes laurisilva forest). It is thus possible to consider butterfly caterpillars (group Macrolepidoptera) or locust larvae (Orthoptera/Caelifera) as possible originators of marginal feeding. The ophionome mine could have been caused by the larvae of leaf-miner flies (Agromyzidae) or moths from the group Microlepidoptera (Gracillariidae). Wood-destroying beetles could be the cause of the boring in fossil wood.

Comment on: Plant–insect interactions in the Quaternary fossil record of the Azores Archipelago (Portugal). Pokorný and Borges (2023). Journal of Quaternary Science 38(4), 597–607

“…We would like to congratulate Pokorný and Borges (2023) (hereafter P&B) on their recent and interesting paper published in this journal, describing the plant-insect interactions found in the Azorean Quaternary fossil record, mainly based on the study of palaeobotanical historical collections. We agree with their main conclusions, namely that most of the illustrated leaf fossil impressions show clear plant-insect interactions.…”

“…For example, land‐snail shell fossils (Gastropoda) have been known since the mid‐19 th century from Santa Maria Island (see Callapez et al, 2003 and references therein). Fossil insects are mentioned from limnic sediment cores, collected from several islands of the Azores: Connor et al (2016), a reference cited in Pokorný and Borges (2023), state the presence of beetle (Coleoptera) fossils in the Caldeirão crater, Corvo island; Raposeiro et al (2021b, supplementary material) and Ritter et al (2022) report the presence of Chironomidae (Diptera) larvae fossils within limnic sediments from several Azorean lakes. Machado (2019) also states the presence of fragmentary insect somatofossils associated with Monte Brasil plant fossils (Terceira Island; see Góis‐Marques et al, 2019c).…”

A response to the comment on the article: Plant—insect interactions … (Pokorný and Borges, 2023), by Góis‐Marques, Madeira and Menezes de Sequeira

“…We gratefully appreciate the comments made by Carlos A. Góis‐Marques, José Madeira and Miguel Menezes de Sequeira (hereafter CAG‐M et al) on our recent paper in the Journal of Quaternary Science (Pokorný and Borges, 2023). We would like to respond regarding the content and partly also the tone of their comments.…”