Published online by Cambridge University Press: 10 July 2009
A radioimmunoassay (RIA) was developed that utilizes 125I-linked Protein A as a tracer to detect the presence of antibodies to an antigen of Mansonia larvae. Antiserum was made by periodic injections of ground gut of fourth-instar larvae of M. dyari Belkin, Heinemann & Page into a rabbit, bleeding the rabbit by cardiac puncture and separating the serum. Using the rabbit antiserum at various dilutions, the specificity of the antibody to Mansonia was examined in tests with seven other mosquito species of different genera. Although there was low-level cross-reactivity with all the other species, the differences in reactivity between those and Mansonia larvae ranged between 2·5 and 8·4-fold; therefore, positive identification was possible. Furthermore, one fourth-instar Mansonia larva could be detected within a predator (fourth-instar larvae of Toxorhynchites rutilus rutilus (Coquillett) 48 h after consumption using the RIA.