Seed choice in ground beetles is driven by surface-derived hydrocarbons

Abstract

Ground beetles (Coleoptera: Carabidae) are among the most prevalent biological agents in temperate agroecosystems. Numerous species function as omnivorous predators, feeding on both pests and weed seeds, yet the sensory ecology of seed perception in omnivorous carabids remains poorly understood. Here, we explore the sensory mechanisms of seed detection and discrimination in four species of omnivorous carabids: Poecilus corvus, Pterostichus melanarius, Harpalus amputatus, and Amara littoralis. Sensory manipulations and multiple-choice seed feeding bioassays showed olfactory perception of seed volatiles as the primary mechanism used by omnivorous carabids to detect and distinguish among seeds of Brassica napus, Sinapis arvensis, and Thlaspi arvense (Brassicaceae). Seed preferences differed among carabid species tested, but the choice of desirable seed species was generally guided by the olfactory perception of long chain hydrocarbons derived from the seed coat surface. These olfactory seed cues were essential for seed detection and discrimination processes to unfold. Disabling the olfactory appendages (antennae and palps) of carabid beetles by ablation left them unable to make accurate seed choices compared to intact beetles.

A large‐scale field experiment of artificially caused landslides with replications revealed the response of the ground‐dwelling beetle community to landslides

“…Ground‐dwelling beetles are useful bioindicators because of their quick response to environment change (Rainio & Niemelä, 2003). Further, some of ground‐dwelling beetles are known as seed predators and can mediate seed dispersal (Ali et al, 2022; de Vega et al, 2011; Griffiths et al, 2016; Müller et al, 2022), and even some fungi are dispersed by ground‐dwelling beetles (Heitmann et al, 2021; Vašutová et al, 2019). Moreover, plant growth enhancement by some species of ground‐dwelling beetles through improving soil quality was reported (Nichols et al, 2008).…”

Sex-specific foraging response to interspecific interactions in carabid beetles

“…(Ali and Willenborg, 2021;Foffová et al, 2020;Gaba et al, 2019;Honek et al, 2007). It has been recently suggested that the primary sensory mechanism used by carabid beetles to detect and distinguish seeds is olfactory perception and that final choice is determined by surface-derived hydrocarbons (Ali et al, 2022). Thus, foraging in carabid beetles is likely an active process guided by specific sensory information gathered from the environment to assess overall food quality (Ali et al, 2022;Kielty et al, 1996;Law and Gallagher, 2015;Tréfás et al, 2001).…”