Recent studies have examined the effects of adult diet on the mating success of male tephritid fruit flies. In most cases, comparisons involve males that have either been fed yeast hydrolysate continuously or not fed yeast hydrolysate at all. As such, this research does not address the more likely ecological scenario of temporal variability in protein availability faced by wild flies. The present study monitored the effect of short-term yeast hydrolysate deprivation on the mating success of male melon flies, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae). Males attained sexual maturation while provided a sugar-yeast hydrolysate mixture (full diet) and were then either maintained on the full diet (control males) or transferred to a sugar-only diet (treated males). Mating trials conducted in field tents showed that treated males achieved fewer successful matings than control males when tested 3 or 7 d after feeding on the sugar-only diet. However, treated males had similar mating success as control males when tested only 1 d after the diet shift. A second experiment employed the same protocol, but yeast hydrolysate-deprived males were given access to cue-lure, a male attractant known to enhance mating success, 1 d before testing. Cue-lure exposure enhanced the mating success of males deprived of yeast hydrolysate for 1 or 3 d but had no effect among males that fed on sugar alone for 7 d before testing. These findings are compared with those obtained previously on a related species, Bactrocera dorsalis (Hendel).