Emerald ash borer

The emerald ash borer ("Agrilus planipennis" or "Agrilus marcopoli") is a shiny green beetle native to Asia. It made its way into the United States on accident and has since been spread to eleven states and to the border with Canada.
The beetle is an invasive species, and a serious pest which destroys ash trees. It has killed at least 25 million ash trees so far and threatens to kill most of the ash trees throughout North America.
Adults lay eggs in crevasses in the bark. Larvae burrow into the bark after hatching and consume the living tissue of cambium and phloem. This causes death within two years. The average emerging season for the emerald ash borer is early spring to late summer. Females lay around 75 eggs, but up to 300 from early May to mid-July. The borer's life cycle is estimated to be one year in southern Michigan but may be up to two years in colder regions.
Huge efforts have been made to slow down its spread, but nothing has worked so far. Parasitoid wasps from Asia are being released, and a fungus which kills insects is being tried.