Figure 1: Life cycles of hemlock woolly adelgid (______) and its introducedpredators, Sasajiscymnus tsugae (______) and Laricobius nigrinus (______) ineastern North America. Solid lines indicate relative active periods of adultand larval predator feeding on the adelgid. Note the two periods highlighted inyellow when prey biomass is high and of excellent nutritional value [25,28-30].