Abstracts (first author)
Fitness effects of warning signals through different life-stages and phenotypes
Many plants and animals advertise their unpalatability through warning signals in the form of colour and shape. A trade-off is inevitably faced to either allocate resources to signal efficiency or to other processes such as thermoregulation (i.e. melanin production). In the case where organisms undergo different phenotypes throughout their lifespan, such as Lepidopterans, it is unclear if allocating resources to warning signals in one phenotype can transfer fitness advantages to the next phenotype. Here we address this question by rearing full-sib tiger moth larvae (Parasemia plantaginis) in high and low temperature conditions and follow their warning signal development until adulthood. Subsequently, we tested for fitness differences as measured by survival and adult heating and metabolic rates. Our analyses showed that larvae reared at low temperatures had higher survival rate and decreased their signal size along its development, producing more melanised body segments. However, adults reared in higher temperatures had higher amount of melanin in their thorax. No clear differences were observed in the amount of melanin in the fore and hind wings between treatments. Adults reared at high temperature had a faster heating rate. On the other hand, adults reared at low temperature needed longer heating time, but had higher body temperature when flying was engaged. No differences were found between metabolic rates between adults of both treatments. Overall, our results suggest that allocating resources to maximise fitness during one life phase or phenotypic stage, does not necessarily translates into higher fitness in the following stages.