Predatory lizards perceive plant‐derived volatile odorants

Abstract

Many lizards are olfactory foragers and prey upon herbivorous arthropods, yet their responses to common herbivore‐associated plant volatiles remain unknown. As such, their role in mediating plant indirect defenses also remains largely obscured. In this paper, we use a cotton‐swab odor presentation assay to ask whether lizards respond to two arthropod‐associated plant‐derived volatile compounds: 2‐( E )‐hexenal and hexanoic acid. We studied the response of two lizard species, Sceloporus virgatus and Aspidoscelis exsanguis , because they differ substantially in their foraging behavior. We found that the actively foraging A. exsanguis responded strongly to hexanoic acid, whereas the ambush foraging S. virgatus responded to 2‐( E )‐hexenal—an herbivore‐associated plant volatile involved in indirect defense against herbivores. These findings indicate that S. virgatus may contribute to plant indirect defense and that a species' response to specific odorants is linked with foraging mode. Future studies can elucidate how lizards use various compounds to locate prey and how these responses impact plant‐herbivore interactions.

Dynamic environmental interactions shaped by vegetative plant volatiles

“…The active foraging lizard (Sceloporous virgatus) responds to the GLV (E)-2-hexenal primarily by inducing tongue-icking, which is a known chemosensory behavior. 218 Apart from this example, little is known about the impact of plant volatiles on reptiles. 218,219 Several herbivorous mammals are known to use vegetative plant volatiles as foraging cues.…”

“…218 Apart from this example, little is known about the impact of plant volatiles on reptiles. 218,219 Several herbivorous mammals are known to use vegetative plant volatiles as foraging cues. Goats respond negatively to terpenes emitted by galls formed during gregarious aphid (Salvum wertheimae) infestation of wild pistachio (Pistacia atlantica) trees.…”

“…218 Apart from this example, little is known about the impact of plant volatiles on reptiles. 218,219…”

Sex-Dependent Effects of the Microbiome on Foraging and Locomotion in Drosophila suzukii

“…In most animals, both males and females can adjust their foraging behavior to achieve their nutritional goals and to avoid harmful components, often through the same behavioral and neurophysiological adaptations. Examples include increasing locomotion when starved to promote food searching and acquisition ( Zhao et al, 2011 ; Yu et al, 2016 ), and the ability to sense or differentiate potential food sources based on volatile cues released by the food as well as cues released by associated microbes ( Becher et al, 2012 ; Stensmyr et al, 2012 ; Martini et al, 2014 ; Karageorgi et al, 2017 ; Goldberg et al, 2019 ; Kim et al, 2019 ). However, males and females are distinct in their foraging motivation and reproductive investments.…”

Whiptail lizards (Aspidoscelis exsanguis) recognize invertebrate prey via cuticular hydrocarbons

“…Whiptail lizards (genus Aspidoscelis ) in particular perform a high frequency of chemosensory behaviors both in baseline conditions and when exposed to prey‐associated odors (Baeckens et al., 2017; Cooper et al., 2000), however, few studies have attempted to examine the precise compounds responsible for eliciting prey‐associated chemosensory responses from whiptail lizards. Studies have shown that only insect‐associated chemical cues will elicit a response from actively foraging lizards and that they do not respond to plant‐associated compounds (Cooper, 1997; Cooper et al., 2000)—even those that are associated with herbivorous insects (Goldberg et al., 2019). One study found that lipids and proteins elicit biting by lizards, but that carbohydrates will not (Cooper et al., 2002a); however, this study used chemical cues (pork fat and bovine gamma globulin) that would not be encountered by lizards under natural foraging conditions.…”