Oviposition patterns by the mosquito Culiseta longiareolata in response to location and residual effects of a predator (Salamandra salamandra larvae)

Predators, by altering community structure in a patch, may alter the value of the patch for prey species even after the predators have left - i.e., the predators may have residual effects. The top predator in temporary pools in northern Israel, larval Salamandra salamandra, has been shown to cause increases in abundance of algae and bacteria, presumably because Salamandra reduces densities of species that feed on algae and bacteria or from nutrient recycling. Entering the pool as tadpoles, Salamandra generally metamorphoses and leaves the temporary pools by late winter or early spring, but their residual effects on algae and bacteria may persist for some time afterwards. We compared the number of oviposition events by the mosquito Culiseta longiareolata in a set of artificial pools of which half had formerly contained Salamandra, and half had never contained Salamandra. Culiseta oviposited more frequently in former Salamandra pools. The pools were arranged in a 4 × 6 grid pattern, and oviposition rates were higher in pools along the perimeter of the grid. This may be because perimeter pools are the first pools to be encountered at the site.