Baleba, S. B. S. | Search bioRxiv

bioRxiv2024

Temperature-mediated dynamics: unraveling the impact of temperature on cuticular hydrocarbon profiles, mating behavior, and life history traits in three Drosophila species

In a world grappling with climate change, understanding the enduring impact of changes in temperature on insect adult traits is crucial. Here, we explored the intricate dynamics of exposure to different temperatures in three Drosophila species: Drosophila ezoana originating in Arctic regions, D. novamexicana in arid, hot environments, and in the cosmopolitan species D. virilis. Rearing these flies at 15, 20, 25, and 30{degrees}C revealed striking variations in their cuticular hydrocarbon (CHC) profiles, known to mediate mate recognition and prevent water loss in insects. The cold-adapted D. ezoana consistently exhibited reduced CHC levels with increasing temperatures, while the warm-adapted D. novamexicana and the cosmopolitan D. virilis displayed more nuanced responses. Additionally, we observed a significant influence of rearing temperature on the mating behavior of these flies, where those reared at the extreme tempreatures, 15 and 30{degrees}C, exhibiting reduced mating success. Consequently, this led to a decrease in the production of adult offspring. Also these adult offspring underwent notable alterations in life history traits, reaching adulthood more rapidly at 25 and 30{degrees}C but with lower weight and reduced longevity. Furthermore, among these offspring, those produced by the cold-adapted D. ezoana were more vulnerable to desiccation and starvation compared to those from the warm-adapted D. novamexicana and the cosmopolitan D. virilis. In summary, our research underscores the intricate interplay between temperature, ecological adaptation and various life history traits in Drosophila species from distinct agro-ecological regions. The observed variations in CHC profiles, mating behavior, fertility and responses to environmental stressors collectively provide valuable insights into how environmental conditions shape the biology and ecology of insects.

ecology↗

bioRxiv2023

Temperature-dependent modulation of odor-dependent behavior in three drosophilid fly species of differing thermal preference

Rapid and ongoing climate change increases global temperature and impacts both feeding and reproduction in insects. The sense of smell plays an important underlying role in these behaviors in most insect species. Here, we aimed to investigate how changing temperatures affect odor detection and ensuing behavior in three drosophilid flies: Drosophila novamexicana, D. virilis and D. ezoana, species that have adapted to life in desert, global and subarctic climates, respectively. Using a series of thermal preference assays, we confirmed that the three species indeed exhibit distinct temperature preferences. Next, using single sensillum recording technique, we classified olfactory sensory neurons (OSNs) present in basiconic sensilla on the antenna of the three species and thereby identified ligands for each OSN type. In a series of trap assays we proceeded to establish the behavioral valence of the best ligands and chose guaiacol, methyl salicylate and isopropyl benzoate as representatives of a repellent, attractant and neutral odor. Next, we assessed the behavioral valence of these three odors in all three species across a thermal range (10-35 C), with flies reared at 18{degrees}C and 25{degrees}C. We found that both developmental and experimental temperatures affected the behavioral performance of the flies. Our study thus reveals temperature-dependent changes in odor-guided behavior in drosophilid flies.

ecology↗