Wild-caught Anopheles darlingi females were tested with one control and one DDT treated excito-repellency test box in March of 1980 and 1981 at Amazonas, Brazil. Three tests each were conducted with unengorged (not blood fed), recently (recent fed) engorged and late (late fed) engorged specimens. The initial tests were conducted during 1980. Following this the boxes were left undisturbed at the field site for 1 year, at which time 3 additional tests with recently engorged specimens were conducted. The escape rate of An. darlingi females from the DDT treated box was uniformly greater than from the control box in all tests, regardless of physiological condition of the mosquitoes. Significant differences in escape rates occurred during the first 5-10 min observation period (s) in most tests and continued to be significant for the remainder of each 60 min test period. "Recent fed" females were less prone to escape from both the DDT and control boxes than were "late fed" and unfed females. Escape rates for "recent fed" females from the DDT treated box in April 1981 were essentially identical to those obtained with the same box and DDT treatment in March 1980. Included is a discussion of the test results plus comments on the test method and options for analyses of excito-repellency test data.
