Abstract
Many organisms show signs of deterioration with age, both in terms of
survival and reproduction. Theory suggests that variation in such
senescence patterns can be driven by resource availability or
reproductive history. To test this prediction, we experimentally
manipulated nutritional stress and age at first reproduction to
investigate senescence in tsetse flies (Glossina). Across all
treatments, offspring weight and survival followed a concave curve with
mother age. Nutritionally stressed females had accelerated survival
senescence, higher probability of abortion and produced smaller
offspring. Despite this, there was no evidence of accelerated
reproductive senescence in nutritionally stressed females and no
evidence of a delay in senescence in females mated later. Offspring
quality may be prioritised over somatic maintenance. Younger females who
were nutritionally stressed produced offspring with the lowest
starvation tolerance. As tsetse are vectors of trypanosomes, our results
may have implications for population dynamics and trypanosome
transmission in times of stress.