Harrison, SJ; McEwen, PK

Journal of Applied Entomology [J. Appl. Entomol.], vol. 122, no. 6, pp. 343-344, Sep 1998

The solubility of L-tryptophan was significantly greater in 2 M hydrochloric acid than in water. In acidic solution, L-tryptophan formed the hydrochloride salt (C sub(11)H sub(12)N sub(2)O sub(2)-HCl) with no evidence of further reaction or decomposition occurring. The hydrochloride salt was seen to be readily soluble in water. Solutions containing L-tryptophan in hydrochloric acid have been shown to be attractive to adult green lacewings (Chrysoperla carnea). Previously it has been believed that acid hydrolysis of L-tryptophan breaks the amino acid down into various compounds which are attractive in the field to green lacewing adults. This paper demonstrates that new explanations for the attractivity of these solutions are required.