Table 1.

Relative short-term and long-term repellency of various biorational repellent esters. A repellent monoterpenoid causes relatively high percentage repellency immediately after filter papers are treated and mosquitoes are subsequently exposed. This repellency is drastically diminished if filter papers are allowed to dry for 5 h before being introduced into the testing chamber (time points 315–450 min). By derivatizing monoterpenoids via various biorational approaches, we have developed numerous compounds that are effective in both the short-term and long-term assay, potentially indicating their residual character on treated surfaces. Some compounds were even capable of causing immobilization or knockdown (KD) of exposed mosquitoes. These results may indicate that not only are these repellents highly efficacious but could represent compounds that are much more repellent than chemistries currently being utilized in current repellent technologies.

Natural and Biorational Compounds	Minutes after Treating Filter Paper
	15	90	150	315	390	450
monoterpenoid	32.5	80	87.5	30	21.5	30
derivative 1	10	60	62.5	30	30	40
derivative 2	22.5	92.5	90	70	80	65
derivative 3	KD	KD	KD	27.5	40	55
derivative 4	25	90	92.5	27.5	17.5	20