Europe
Leafy spurge (Euphorbia virgata), cypress spurge (E. cyparissias)
Larvae are up to 5 mm long, slender, whitish, and with a brown head capsule. Adults are shiny black and 3 mm long. Their legs are largely reddish-brown in color, though the tops of the hind femurs sometimes have dark patches. Although adults have fully developed wings and are capable of flight, they more often walk or utilize their enlarged hind legs to jump when disturbed, as is typical of all flea beetles.
Overwintering larvae resume feeding on young roots in early spring as cypress and leafy spurge are resuming growth. Pupation occurs in the soil. Adults are active from early summer to late summer, feeding on spurge leaves and flowers as spurges bolt, flower, and mature. Females lay numerous eggs into the soil throughout the growing season. Hatching larvae burrow into spurge roots to feed, developing through three instars. There is one generation per year. Black-colored adult Aphthonaspp. (A. czwalinaiand A. lacertosa) generally emerge earlier in the spring than brown-colored adult Aphthonaspp. (A. cyparissiae, A. flava, and A. nigriscutis).
Larvae feed on root hairs and young roots, inhibiting root function and stunting spurge stem growth. At some locations, larval feeding damage makes attacked roots more susceptible to soil-inhabiting pathogens. Adults feed on leaves and flowers, decreasing photosynthesis and plants’ sugar-making ability for root reserves.
Milan, J., N.M. West, R.S. Bourchier, and C.B. Randall. 2024. Spurge Biocontrol Agents: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2024-40-SPURGES-A. https://bugwoodcloud.org/resource/files/29180.pdf