Biology subjects

Susanto, E.

Publications and source records attributed to Susanto, E..

3 recordsLinked to original sources

bioRxiv2025

Dehydrating microhabitats increase mite activity and intensify ectoparasitism of Drosophila

Parasites interact with their host in variable environments that are often subject to water scarcity and dehydration. Drosophila fruit flies and associated ectoparasitic mites interact across a range of microhabitats, typically in decaying organic matter, such as fallen fruit and cactus tissue, that dries out and deteriorates over periods ranging from days to months. Here, we report that mite parasitism of Drosophila increases with exposure to increasingly dry conditions for two fly-mite systems (D. nigrospiracula-Macrocheles and D. melanogaster-Gamasodes). In D. melanogaster, artificial selection for behavioral resistance did not eliminate this effect, as previously selected lines remained relatively more resistant than non-selected controls even under dry conditions. Water balance assays confirmed that mites became dehydrated when held under dry conditions, which was also associated with increased mite activity. Exposure of D. melanogaster to mites dehydrated by exposure to low relative humidity increased parasitism, further supporting that mite infestation intensifies under dry conditions. The results indicate that ectoparasitism in this system is affected by the water content of the mites. The increased motivation of mites to parasitise flies under dry conditions may serve to replenish mite water stores and facilitate dispersal to more favorable microhabitats.

physiology↗

bioRxiv2025

Parental exposure to wet and dry conditions shapes the viability and thermotolerance of eggs in Aedes aegypti

Aedes aegypti, a primary vector of dengue, Zika, and chikungunya, displays remarkable adaptability across ecological gradients. Central to this resilience is the egg stage, which must withstand fluctuating moisture and temperature conditions. Environmental transitions, particularly changes in moisture availability, significantly influence egg hatching success in mosquitoes. This study investigates how parental exposure to variable hydration conditions shapes key reproductive traits in Ae. aegypti. Using four environmental regimes, continuous wet, continuous dry, wet-to- dry, and dry-to-wet, we assessed egg output, hatching success, thermotolerance, and egg nutrient composition across three Ae. aegypti populations. Our results show that oviposition timing and egg production are significantly affected by the hydration environment experienced by the parental generation. While the wet, dry, and dry-to-wet groups exhibited a consistent oviposition peak beginning four days post-blood feeding, the wet-to-dry group showed delayed reproductive investment, with peak egg production occurring later. Egg output was highest under continuous wet conditions and significantly reduced in the dry and wet-to-dry treatments across all populations. Interestingly, the wet-to-dry group showed significantly higher egg-thermotolerance than any other group, and this pattern was consistent across all three populations under high- temperature stress conditions (41{degrees}C and 45{degrees}C). Nutritional composition showed an increased glycogen level in eggs when parents were exposed to wet conditions before blood feeding. By integrating physiological and ecological metrics such as hatching rates and thermal stress resilience, we demonstrate how parental environments shape subsequent egg performance, highlighting adaptive responses that enable Ae. aegypti persistence under increasing climate variability.

physiology↗

bioRxiv2025

A microbiome-derived transfer RNA modification underlies behavioral optimums and predator avoidance in mosquito larvae

The gut microbiome is a rich source of nutrients that are critical to the development and biology of eukaryotes. Transfer RNAs (tRNAs) are essential components of protein synthesis, and some chemical modifications to tRNA rely on the availability of microbiome-derived nutrients. In eukaryotes, the micronutrient queuosine (Q) is salvaged from the microbiome or diet and then incorporated into eukaryotic tRNA to influence the speed and efficiency of protein synthesis. Here, we examine the role of microbiome-derived Q in mosquito larval development and behavior. When mosquito larvae are grown with a microbiome incapable of synthesizing Q, there is a significant impact on tyrosine levels and processes, which correlate with defects in behavior and cuticle formation. Due to defects in movement and behavioral responses, Q-deficient larvae demonstrate impaired predator evasion, leading to higher instances of capture by predaceous beetle larvae. The broad effects of Q-deficiency in mosquito larvae highlight the importance of microbiome-derived nutrients for eukaryotic physiology and behavior.

physiology↗