Hanging in balance: The predator's dilemma

Third Place

A juvenile orb-weaver hangs precariously from the branch of a Balsam fir seedling, one of ninety-six plants. Below him, he faces a problem: a barrier fashioned from sheer white fabric. This barrier separates him from a smorgasbord of eastern Spruce budworm larvae... but to enter, may mean to never escape! My Masters in Science in Forestry thesis studied the effects of elevated temperatures on spruce budworm and its host trees. To do this, we installed mini-greenhouses (called phytotrons) to control temperature, and used sleeve cages (similar to a small pillow case) to contain spruce budworm (a defoliating insect) larvae on the lower half of the plant, so we could study the effects of both temperature and insect on the seedlings. The warmth and safety of phytotrons attracted many different types of insects, including predators such as our young spider. Throughout the experiment, we observed some predation - but to slip into the cage, meant to stay in the cage! Predators, like ants and spiders, could squeeze into the cage, but often perished within, truly capturing the predator's dilemma! This photo was taken with my Olympus Pen F, using a 30mm lens.