2026/05/21 by S. Engels, O. Heiri, J. Hinkelman +1 · 1 citation
Agricultural and Biological Sciences · #Fossil Insects in Amber #Collembola Taxonomy and Ecology Studies #Plant Diversity and Evolution
paper · doi:10.1016/j.revpalbo.2026.105632
Van Geel and co-workers were the first to designate chironomid and other insect remains as non-pollen palynomorph (NPP) types in the 1980s, and there are currently at least 30 NPP types that describe insect remains. Here we review the potential use of chironomid NPPs, one of the most common groups of aquatic insects prevalent as NPPs on pollen slides. Chironomid remains in lake sediment records are frequently used in palaeoecological studies to quantitatively reconstruct changes in the past environment, with summer temperature reconstructions being a particular research focus. Whereas studies specifically aimed at chironomid analysis typically aim to isolate e.g. 50–100 head capsules, the number of chironomid remains encountered on pollen slides is much lower, reflecting the lower concentrations of chironomids in lake sediments compared to pollen, as well as the loss of and damage to chironomid remains during laboratory processing for pollen analysis. Chironomid remains on pollen slides are typically smaller than those encountered during standard chironomid analysis, and consist of detached structures originating from chironomid larvae and pupae, such as the mentum, mandibles, ligulae, claws or epaulettes or more complete head capsules of young instars. Complete, later instar head capsules are typically missing from pollen slides. The low count sums of chironomid remains encountered on pollen slides will preclude quantitative reconstructions, and will introduce an element of uncertainty to palaeoenvironmental inferences based on these remains. Nevertheless, this paper argues that chironomid remains encountered on pollen slides have the potential to provide important supporting palaeoecological information, particularly for studies using pollen to reconstruct past changes in local environments. Especially when combined with independent lines of evidence and other NPPs originating from freshwater habitats, chironomids can provide auxiliary information on the depositional environment, on past trophic levels or on other ecological parameters.