Habitat isolation and the cues of three remote predators differentially modulate prey colonization dynamics in pond landscapes

Interactive effects of dragonfly larvae and Bacillus thuringiensis var. israelensis on mosquito oviposition and survival

“…Aquatic predators are known to reduce mosquito oviposition by deterring gravid mosquitoes. However, contrary to our expectation, dragonfly predators in our study did not deter mosquito oviposition although Cordulia aenea and Aeshna cyanea dragonfly larvae had been shown to reduce oviposition in C. pipiens mosquitoes in an experiment in a temperate region (Santangelo et al, 2021). This could perhaps be due to weaker (low concentration) chemical cues from predators that could not reach the threshold that could elicit avoidance behavior in gravid mosquitoes.…”

“…Finally, as an additional level of complexity, we inoculated both simple (two-trophic level: algae and zooplankton) and more complex (three-trophic level: algae, zooplankton, dragonfly predators) communities in the experimental mesocosms. We hypothesized (H 4 ) that the presence of dragonfly larvae as an apex predator might reduce mosquito oviposition, as shown earlier for C. pipiens in Belgium (Santangelo et al, 2021), but only if they would be able to survive the Bti treatment. This can illustrate how the differential sensitivity to pesticides in predators and prey may affect the effectiveness of larval control strategies using pesticides.…”

“…Finally, it is not well understood to what extent mosquito habitat selection patterns and resulting population dynamics may be shaped by the presence of multiple cues in landscapes. For instance, it has recently been shown that they avoid cues from invertebrate predators such as dragonflies (Santangelo et al, 2021) or predatory mosquitoes (Turner et al, 2020). As such, it would be important to investigate how mosquito reproduction occurs in mosaic landscapes where both cues of predators and pesticides can be present.…”