Olfactometer and large cage evaluation of a solid phase technology for the controlled production of CO2

New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactometer and large outdoor cage tests against laboratory-reared Aedes aegypti for potential use in mosquito surveillance programs. The proprietary CO2 generation system consists of a poly-Tyvek sachet containing 2 solid ingredients. Activated sachets immediately react to generate and release predictable levels of CO2 over time. In noncompetitive olfactometer studies, a freshly activated sachet attracted an average +/- SE of 96.6 +/- 0.9% of the available mosquitoes compared with 20.2 +/- 6.5% for 5 ml/min CO2 released from a compressed gas cylinder. In competitive tests, the sachet attracted 92.4 +/- 1.2% compared with 0.9 +/- 0.5% for the compressed gas. In the olfactometer, aged sachets attracted >90% of the available mosquitoes up to 8 h and ca. 27% 1 wk after activation. In the large outdoor cages, traps baited with activated sachets captured 2.2-5.4 times as many mosquitoes as unbaited traps, depending on time of testing after activation.