"Ash tree above the mist" by Alasdair Thomson ©


From conception to death the life span of Agrillus Planipennis is roughly one year but may take as long as two years depending on conditions.  Adult emergence occurs anytime from May to August. Adult males have an average lifespan of 13 days while females typically live 21 days. 

Reproduction occurs within ten days upon emerging from the tree in early spring.  Mating is not exclusive as males may interact with several females.   Ovipositing, the “laying” of eggs, by females, in crevices in the ash tree bark and branches, typically is completed seven to nine days after conception.  Experiments have reported females have the ability to lay anywhere from 30-90+ eggs.  After two weeks the eggs will hatch where the larvae will begin to feed on the phloem of the tree.  Cessation of the feeding will occur in October or November upon which the Larvae will burrow one cm into the tree to wait out the cold winter months; a process extremely similar to hibernation in bears.  Finally when temperatures begin to warm (around April) the larvae will mature into a pupae, which will remain in the tree until it is ready to exit as an adult.

Although most Life cycles will take a year, observations have been made noticing two year development.  This is believed to be the result of eggs being laid late in the season (late summer/early fall), not allowing sufficient time for the larvae to develop. 


Emergence of Emerald Ash Borer from Ash tree.