Surviving dessication is a major problem for natural populations and a model trait to study adaptation. Despite the relevance of resistance to dessication, its ecological and evolutionary dynamics remain almost unstudied in polyphagous insects. Using Anastrepha ludens Loew flies, we characterized dessication resistance across 10 generations in a dry environment. We found a change in several life-history traits. Experimental evolution resulted in a two-fold increase in desiccation resistance, increase in longevity, heavier flies, higher teneral reserves of water and lipids and longer pupal period. No differences in male mating competitiveness were found and females retained a high reproductive potential. The mayor fitness cost of the tolerant life history was related to the time of reproductive events. Tolerant females were almost 10 days slower at maturing than non-tolerant females. Our results demonstrate that desiccation resistance can evolve at an extremely rapid pace in this insect, with a diffuse trade-off on reproduction. This adaptation was most likely due to the standing genetic variation of populations that favours the plasticity of polyphagous insects.