Dopamine levels in mosquito heads. (A-D) Dopamine levels (pg/mosquito head) in Wolbachia infected (+ Wolb) and uninfected A. aegypti mosquitoes (- Wolb) of three different ages (5, 15 and 30 days-old). Sample sizes were as follows with each n = pool of 5 heads; 5 days n = 40, 15 days n = 26, 30 days n = 22-42. On D a replicate experiment is shown. *P < 0.05, **P < 0.01.