Abstract. 1. This study uses pitfall traps and sticky traps to examine the effects of elevated CO2 on the densities of insect herbivores, insectivores, and detritivores.
2. Pitfall trapping for the last 3 years of 11 years of continuously elevated CO2 revealed increases of insect herbivore species such as Thysanoptera (thrips), Hemiptera, and Lepidoptera, but no effects on insectivores such as spiders, parasitic wasps, and ants; or on detritivores such as Diptera (flies), Psocoptera (book lice), Blattodea (cockroaches), Collembola (spring tails), Orthoptera (crickets), and Coleoptera (beetles).
3. As the bottom-up effects of elevated CO2 are transmitted through plants to herbivores, they do not appear to reach insect natural enemies or decomposers.