Mediterranean Tamarisk Beetle

The MTB overwinters as adults on the ground. Adults become active and begin feeding and mating in the early spring when tamarisk leaves are budding. Eggs are laid on tamarisk leaves and hatch in about a week in warm weather. Three larval stages feed on tamarisk leaves for about two and a half weeks when they crawl to the ground and spend about 5 days as a C-shaped inactive prepupa before pupating about one week. Adults emerge from pupae to complete the life cycle in about 4–5 weeks in the summer. (For images of various life stages of a related species, see Diorhabda carinulata at commons) Five generations of MTB occur through spring and fall in central Texas (Milbrath et al. 2007, Tracy and Robbins 2009). Similar to the northern tamarisk beetle, adults begin to enter diapause in the late summer and early fall, ceasing reproduction and feeding to build fat bodies before seeking a protected place to overwinter (Lewis et al. 2003). Larvae and adults are sensitive to shorter daylengths as the summer progresses that signal the coming of winter and induce diapause (Bean et al. in prep.). Robert Bartelt and Allard Cossé (USDA-ARS, Peoria, Illinois) found that male MTB emit a putative aggregation pheromone, similar to that found in Diorhabda carinulata (Cossé et al. 2005), that could serve to attract both males and females to certain tamarisk trees.