iav1 noted (Kaplan, 1977) to be extremely inactive as adult, with normal external morphology; population of mutants remains quiet and spread out evenly in a container; will walk or fly when container disturbed, but settles into inactivity soon afterward. iav2 noted (Homyk and Sheppard, 1977) to be inactive and difficult to arouse for flight (and, when it does, seems to hover and fixate on objects); to jump and fly abnormally short distances; to exhibit slow running or climbing ability and optomotor response; to be debilitated after mechanical shock (especially in adults more than two weeks old). Gynandromorph analysis of iav2 adult behavioral impairments suggests primary focus could be neural (Homyk, 1977). Open-field activity tests of iav1 and iav2 (O'Dell and Burnet, 1988) showed both to exhibit reduced speed as well as amount of locomotion (the former meaning number of squares in the activity chambered visited/unit time, the latter the proportion of time spent moving); male activity levels higher than for females (also found for wild-type); lower than wildtype levels of activity at all ages between time of eclosion and approximately one-month; yet, unlike wild type, speed and amount of activity increase (in tests of iav2) in parallel between days 1 and 2 of adulthood (reaching a much lower than normal plateau). In tests of homozygous iav1 and iav2 females (with normal males), mating propensity reduced and courtship durations extended, though such females showed normal compositions of cuticular hydrocarbons and were highly attractive to courting males (O'Dell et al., 1989); mutant males with normal females exhibited slightly reduced mating success; mutant males crossed with mutant females had very low mating success rate. Lower than normal octopamine levels, especially in extracts from adult heads (O'Dell et al., 1987), with dopamine and norepinephrine levels apparently normal.