Come to the dark side: habitat selection of larval odonates depends on background visual patterns

Abstract

1. Determining which environmental traits enable animals to inhabit and choose preferred habitats is key to understanding ecological processes. Habitat complexity and background colour patterns can act as selective pressures on animal behaviour, and ultimately affect habitat choice.2. To investigate the role of environmental features on habitat selection, this study looked at whether dragonfly and damselfly larvae show a preference between dark/light or complex environments. Last‐instar larvae of Micrathyria didyma (Odonata: Libellulidae) and Acanthagrion lancea (Odonata: Coenagrionidae) were collected in the Neotropical savanna, and five experiments in laboratory conditions were subsequently carried out. The first experiment tested the preference of larvae for leaves in contrast to a white background. The second experiment compared a preference for white and black backgrounds. As both experiments showed a significant preference for darker backgrounds, a predator was included in the black background in the third experiment, and a macrophyte was included in the white background in the fourth experiment. In this way, favourable and unfavourable conditions were included in the habitat of choice. The fifth experiment tested the influence of environmental complexity on habitat choice.3. The results of these experiments showed that larvae choose darker backgrounds independently of predation risk, and that macrophytes are as attractive as a dark background. They also suggest that the coenagrionid, but not the libellulid, prefer more complex environments.4. Overall, these findings suggest that larvae exhibit behavioural preferences for background colour and complexity, which may ultimately drive habitat occupation.

Interactions between ecological factors in the developmental environment modulate pupal and adult traits in a polyphagous fly

“…We found a strong interaction between larval density, diet composition, and microbial growth (through the manipulation of preservative content in the diet) on pupal and adult traits of B. tryoni, highlighting the importance of multiple ecological factors in shaping the developmental environment of insect larvae. Given that the developmental environment modulates the expression of life history traits in other invertebrates (Ireland & Turner, 2006;Tavares, Pestana, Rocha, Schiavone, & Guillermo-Ferreira, 2018) and vertebrates (including humans) (Gilbert & Epel, 2009;Gluckman & Hanson, 2006), studies that address how ecology modulates the development of life history traits can help us gain insights into how developmental ecology influence evolutionary processes and adaptions across the animal kingdom (Gilbert, 2001).…”

The role of plasticity in the evolution of cryptic pigmentation in a freshwater isopod

“…However, it is also possible that both biotic and abiotic environmental differences can interact to affect the distributions of phenotypes and fitness, and their covariance. Macrophytes can generate structural complexity (Kovalenko, Thomaz, & Warfe, ) and affect background coloration (Tavares, Pestana, Rocha, Schiavone, & Guillermo‐Ferreira, ), to which not all prey phenotypes are equally well adapted (Lürig, Best, & Stachowicz, ). Thus, differences in macrophyte cover may affect the strength and direction of selection from predation (Merilaita, Lyytinen, & Mappes, ).…”

“…Such results suggest that visual predation along an environmental gradient of background coloration is driving the rapid evolution of cryptic pigmentation of A. aquaticus (Hargeby et al., ). Importantly, macrophytes may alter predation susceptibility by making isopods more or less visible against their background, but also by altering the 3D structure of the habitat and the variety of refugia (Kovalenko et al., ; Tavares et al., ).…”

Urban Pit-Building Insects Are Attracted to Walls for Multiple Reasons

“…It suggests that the apparent preference for walls is achieved by the larvae themselves. It remains to be tested whether ovipositing females lay more eggs next to walls, demonstrating a match between the adult female and larval habitat selection like other insects (e.g., antlions and dragonflies/damselflies [77,78]). Wormlions more distant from the wall relocated more until they reached a wall.…”