Comparing the dispersal abilities of Lygus hesperus and its predators using a novel large-scale mark-capture technique

In annual agroecosystems, a critical characteristic of a successful biological control agent is the ability to disperse rapidly between temporally ephemeral resources. In California’s Central Valley, the generalist pest Lygus hesperus is under poor biological control despite a suite of known predators. One possible explanation is a discrepancy in the dispersal ability of the pest and its predators. To examine this directly, we preformed a multi-year, large-scale mark-capture study where we marked alfalfa fields containing L. hesperus and its predators with aerial applications of protein markers. Following marking, the field was harvested for hay by the grower, which prompted a dispersal event. At several times following harvest, surrounding cotton fields were sampled at known distances from the marked field for L. hesperus and its predators, including: big-eyed bugs (Geocoris spp.), damsel bugs (Nabis spp.), green lacewings (Chrysoperla spp.), and convergent lady beetles (Hippodamia convergens). The results of this work illustrate the dispersal ability of an insect pest relative to its suite of generalist predators and has implications for the landscape-scale management of L. hesperus.