What Lies Beneath? The Art and Science of Soil Arthropods
Seasonal phenology considerations may inform management strategies for subterranean termites: The social cockroaches eating your home from the ground up
Wednesday, November 16, 2022
11:10 AM – 11:25 AM PT
Location: Vancouver Convention Centre, Meeting Room 211
Urban IPM Advisor University of California Hayward, California
Subterranean termites (Blattodea: Rhinotermitidae) are common yet cryptic members of soil communities worldwide, providing important ecosystem services but also representing significant pests. The western subterranean termite, Reticulitermes hesperus Banks, is the most pestiferous wood-destroying organism in western North America, where it commonly attacks homes and other wooden structures. Adapted to the Mediterranean climate of the Pacific Northwest, characterized by mild wet winters and hot dry summers, R. hesperus is known to exhibit marked seasonal patterns, with increased foraging near the soil surface during winter and spring and decreased foraging during summer and autumn. Two major phenotypes of R. hesperus have been observed in California, where some colonies form mating flights (swarms) in spring and others in autumn. This bimodal swarm phenology may indicate speciation in progress or a cryptic species complex since phenotypes can readily be distinguished with molecular characters but not with morphological characters. Autumn-swarming colonies may be observed within a limited distribution in the San Francisco Bay Area and adjacent portions of the Sacramento Valley while spring-swarming colonies may be observed across most of the species’ range, from southern British Columbia to central Baja California. Autumn swarming may be an adaptation to earlier onset of the dry season in a changing climate. Understanding these seasonal patterns of activity helps pest control operators to more effectively monitor and control western subterranean termites. For instance, interception times for chitin synthesis inhibitor bait systems can be significantly reduced when stations are installed at the beginning of the wet season.