The adult beetles spend the winter in the soil and plant litter. They emerge in the spring after the loosestrife plants have begun to grow and lay eggs on the leaves and stems. The developing larvae feed on leaves and growing points of the plant, limiting the plants' growth and flowering. The larvae pupate in the soil before emerging as adults the same year in early summer. The number of generations per season varies from one in cooler areas to two or possibly more in hotter areas with longer growing seasons.
Adults generally live for a year or less.
The total number of Galerucella spp adults released from Bureau of Reclamation mass-production programs was about 40,000. During this time, we monitored the number of insects at the site and made measurements of plant vigor, including height, density and flowering. We also took aerial photos of nearly 6,000 acres of the Winchester Wasteway area in 1995 and again in 1998. These photographs illustrate how the Winchester Wasteway site has changed between 1995 to 1998. Note the landmark tower in the upper right.