Big Brother is Watching: Studying Insect Predation in the Age of Digital Surveillance

Abstract

We describe a novel video system constructed from readily available security equipment for recording insect predator behavior in the field. Our system consists of a multi-channel digital video recorder (DVR), active night vision cameras, a deep cycle marine battery, and a weatherproof housing. The major advantages of these systems over previous generations of video equipment include reduced expense, improved deployment times, faster frames per second, and higher video resolution. We tested our systems in a pair of experiments: the first assessed the effects of ground cover on predation of key pests in blueberries, and the second investigated predator activity in corn and perennial prairie systems. We identified ants as the most frequent predators in all three ecosystems, with notable activity from arachnids, crickets, and mollusks. Interactions between coleopterans and prey were surprisingly infrequent in all three agroecosystems. Ants were observed under both day and night conditions, while other predators were primarily nocturnal. Ground covers did not significantly affect predator activity in blue-berries, but there was a numerical reduction in ant activity on woodchips and weed barrier compared to grass and bare ground. The predator complex observed in blueberry video footage differed considerably from pitfall captures at the same site. In corn fields, prey mortality significantly increased with ant activity, and high prey mortality was associated with long interactions that involved large numbers of ant foragers. Digital videography of insect predators is a very useful tool for identifying key taxa responsible for the removal of sentinel prey and documenting their behavior.