The effects of starvation and repeated disturbance on mass loss, pit construction, and spatial pattern in a trap-building predator

1. Starvation tolerance is an important trait for animals, as most will encounter starvation within their lifetime. Sit-and-wait predators are better adapted to starvation owing to their naturally low encounter rate with prey. 2. Starvation tolerance was studied under three levels of disturbance of wormlion larvae, a strict sit-and-wait predator that constructs pits. 3. Frequently disturbed wormlions constructed pits less often, and larger individuals continued to construct pits more frequently than smaller ones. It was expected that a high disturbance level would lead to a high rate of mass loss, however, surprisingly, the rate of mass loss was not higher for the frequently disturbed group. This suggests that the energetic cost of pit construction and maintenance is not as high as previously suggested for other pit-building predators. 4. Larger individuals tolerated starvation better, in losing a lower proportion of their initial body mass and having higher chances of survival throughout the experiment. 5. The effect of starvation on the distance to neighbours was also investigated, and starved individuals were expected to maximise this distance in order to avoid interference competition. However, wormlions were usually clumped, and starvation or feeding had no effect on the pits' spatial pattern, suggesting that interference competition plays a minor role in this species. 6. Generally, wormlion larvae demonstrated a high starvation tolerance and low mortality rates even after 9 weeks of starvation.