Thermal Growth Range and Interaction Between <i>Drosophila</i> Spp and <i>Pichia kudriazevii</i>

The symbiotic interactions between fungi and Drosophila reveal complex ecological dynamics and host-pathogen co-evolution. We explored how the thermal adaptation of Drosophila species correlates with their interaction with P. kudriazevii. Collections from three geographical locations showed a higher association frequency of P. kudriazevii (Saccharomycetales: Pichiaceae) Boidin, Pignal and Besson (isolate zibd3) with the warm-adapted Zaprionus indianus Gupta (Diptera: Drosophilidae) compared to the generalist D. melanogaster Meigen and cold-adapted D. nepalensis. Fungal infection increased larval mortality at 25°C, with the highest mortality in D. nepalensis. Conversely, mortality was lower at 17°C, likely dueto reduced fungal growth. Adult mortality was highest in the non-native species D. nepalensis across all temperatures tested. Fecundity in all species reduced with fungal infection, particularly at higher temperatures (28-31°C). These findings highlight the corelation of thermal preferences, fungal growth, and ecological niches in shaping fungi-Drosophila associations, suggesting co-evolutionary dynamics that affect host survival and reproduction.