Gain-of-function screening in Drosophila melanogaster provides a powerful approach for identifying genes that modulate lifespan; however, induction strength and environmental stress can substantially influence phenotypic outcomes. Here, we performed a pilot Gene Search (GS)-based overexpression screen using a heat-inducible hs-GAL4 driver and compared lifespan analyses at 25 °C and 30 °C to evaluate the impact of induction conditions on the detectability of lifespan-modulating genes. Induction at 30 °C caused uniformly shortened lifespans across genotypes and did not reveal robust lifespan-extending candidates. In contrast, screening at 25 °C, where moderate hs-GAL4 induction produces robust and detectable transgene expression, revealed multiple longevity-promoting lines. Lifespan measurements at the two temperatures were poorly correlated, indicating that elevated temperature imposes a dominant physiological burden that masks gene-specific effects. Using this strategy, we characterized a candidate line overexpressing Drosophila Ankyrin repeat and MYND domain-containing protein 2 (dAnkmy2). Overexpression of dAnkmy2 significantly extended adult lifespan and enhanced resistance to oxidative stress without detectable changes in canonical antioxidant gene expression. In contrast, loss of dAnkmy2 caused larval lethality, indicating an essential developmental function. Given the conserved role of Ankmy2 in ciliary biology, our results raise the possibility that cilia-associated processes may be involved in lifespan regulation. Collectively, this study establishes a proof-of-principle framework for detecting subtle genetic modulators of aging in genetically robust systems.