Preparation of amino acids meal or feeding buffer for mosquito feeding Amino acid meals was prepared according to Noriega et al. [33] with modifications. Briefly, the amino acids meal consisted of 40 ml of amino acid-deficient M199 media (dM199) (Invitrogen Corporation, Carlsbad, CA), 1.6 ml of 1006 MEM nonessential amino acid solution (Mediatech, Inc., Herndon, VA), 3.2 ml of 506 MEM amino acid solution (Mediatech, Inc.), and 10 mg of HEPES (Sigma, St. Louis, MO) (pH 7.2), with a final concentration of 2.3 mg/ml total amino. Just before feeding mosquitoes, ATP (Sigma) was added to the meal to a final concentration of 5 mM. The feeding buffer was composed of 100 mM NaHCO 3 and 150 mM NaCl, pH 7.2, as described by Kogan [35] .