Bigger isn't always better: Challenging assumptions about the associations between diapause, body weight, and overwintering survival.

During the winter, animals face limited food availability. Many animals enter dormancy to reduce their winter energy expenditure. Most insects spend the winter in diapause, a state of programmed dormancy. It is often assumed that diapausing insects need nutrient stores to fuel their many months of basal metabolism and must grow heavier than their non-diapause-programmed counterparts. However, the extent to which food limitation affects body weight during overwintering preparation as well as the likelihood and duration of diapause remains unclear. We limited the duration of the feeding period and thus the total quantity of food available to diapause-destined larvae of the pupal-diapausing flesh fly, Sarcophaga crassipalpis, to test how food limitation affects body weight in the context of diapause programming. We also tested the extent to which food deprivation and body weight affect the likelihood and duration of diapause. We hypothesized that diapause-destined larvae grow more quickly and pupariate at a heavier body weight than non-diapause larvae. We also hypothesized that body weight is more dramatically reduced by food limitations when a larva is programmed for diapause. Finally, we hypothesized that larvae with lighter body weight (i.e., food limited) are less likely to enter pupal diapause and also stay in diapause for a shorter duration than heavier, well-fed, individuals. Contrary to our hypotheses that diapausing insects are heavier than their non-diapausing counterparts, we found diapausing pupae weighed less than non-diapausing pupae, especially when larvae received limited food. We found light pupae did not abort their diapause program. In both diapausing and non-diapausing pupae, body weight was positively correlated with simulated winter survival. However, above a weight threshold, body weight no longer affected simulated winter survival in diapausing pupae. Contrary to our predictions and the general consensus in much of the diapause literature, we also found that lighter pupae stayed in diapause longer than heavier pupae. Overall, our results challenge the precept that body weight and diapause are positively associated. The relationship between body weight and diapause is complex and may be affected by the availability of food before and after winter, the availability of high-quality overwintering sites, and the life history of a particular insect.

Age-related disgust responses to signs of disease.

Previous studies found similarities in adults' disgust responses to benign (e.g. obesity) and actual disease signs (e.g. influenza). However, limited research has compared visual (i.e. benign and actual) to cognitive (i.e. disease label) disease cues in different age groups. The current study investigated disgust responses across middle childhood (7-9 years), late childhood (10-12 years), adolescence (13-17 years), and adulthood (18+ years). Participants viewed individuals representing a benign visual disease (obese), sick-looking (staphylococcus), sick-label (cold/flu), and healthy condition. Disgust-related outcomes were: (1) avoidance, or contact level with apparel the individual was said to have worn, (2) disgust facial reactions, and (3) a combination of (1) and (2). Avoidance was greater for the sick-looking and sick-label than the healthy and obese conditions. For facial reaction and combination outcomes, middle childhood participants responded with greater disgust to the sick-looking than the healthy condition, while late childhood participants expressed stronger disgust towards the sick-looking and obese conditions than the healthy condition. Adolescents and adults exhibited stronger disgust towards sick-label and sick-looking than obese and healthy conditions. Results suggest visual cues are central to children's disgust responses whereas adolescents and adult responses considered cognitive cues.