Eastern elderberry borer mating pair

Adult elderberry borers feed on leaves and pollen from the flower heads of elderberry, and female beetles lay their eggs near the base of the elderberry plant. Upon hatching, the larvae bore into roots where they feed and develop on nutritious plant tissues. However, elderberry is chemically defended by potent cyanogenic glycosides, toxic compounds that are believed to be passed along from larvae to adults. A taste of these noxious chemicals during an attack may teach a predator that large dark blue and yellow insects are not to be included on the menu.

Around 25 mm body length