Polyunsaturated fatty acids (PUFA) are vital nutrients that support the metabolic activities of animals. Emergent insects that develop in aquatic habitats during their larval stages and transition to terrestrial environments as adults play a key role in transferring aquatic-derived PUFA, such as EPA (Eicosapentaenoic Acid), and DHA (Docosahexaenoic Acid), to terrestrial systems. The dynamics of PUFA production and transport between ecosystems, and the role insects play in this process, have garnered increasing attention over the past decade, particularly in light of changing climates and temperatures. However, a systematic comparison of insect PUFA profiles between aquatic and terrestrial ecosystems has not been documented.
Here I discuss the findings from a systematic review that forms part of my PhD project, which aims to investigating the role of alpine insects in cross-ecosystem nutrient flux and the impact of seasonal dynamics on nutrient transfer with a particular emphasis on climate change. A data synthesis approach was employed to compare 107 insect PUFA profiles from aquatic and terrestrial environments focusing on the distribution of five key PUFAs: LIN (Linoleic Acid), ALA (Alpha-Linolenic Acid), ARA (Arachidonic Acid), EPA, and DHA. A multiple comparison analysis revealed that PUFA composition strongly depends on habitat (Aquatic vs Terrestrial), with terrestrial insects having higher levels of LIN and ALA, and aquatic insects having higher levels of ARA, EPA, and DHA. The study highlights the critical role of aquatic insects in facilitating nutrient transfer across ecosystem boundaries.