The effects of analogs of the diuretic peptides Locmi-DH, Dippu-DH46 and Dippu-DH31 on two aspects of appetitive behavior are investigated in previously food-deprived nymphs of Locusta migratoria. The analogs tested are the C-terminal 15-mer and nonapeptides and their corresponding cyclic analogs. At a nominal dose of 1 pmol injected per nymph, the linear fragments and their cyclic analogs of Dippu-DH46 display no significant effects on the latency to feed or on the length of the first meal in nymphs. However, at the same dose, the linear fragments of Dippu-DH31 and their cyclic analogs, and analogs of Locmi-DH modulate appetitive behavior: they are anorexigenic in reducing the duration of the first meal, and generally increasing the latency to feed. The cyclic analogs of Dippu-DH31 are at least as effective as their linear counterparts in influencing these aspects of appetitive behavior in locust nymphs.