Cool headed individuals are better survivors: non-consumptive and consumptive effects of a generalist predator on a sap feeding insect

Non-consumptive effects (NCEs) of predators are part of the complex interactions among insect natural enemies and prey. NCEs have been shown to significantly affect prey foraging and feeding. The lengthy phloem feeding exposes leafhoppers (Auchenorrhyncha) to predation risk and may play a role in pathogen transmission in vector species. However, NCEs on leafhoppers have been scarcely studied, and we lack basic information about how anti-predator behaviour influences foraging and feeding in these species. Here we report a study on non-consumptive and consumptive predator-prey interactions in a naturally co-occurring spider – leafhopper system. In mesocosm arenas we studied movement pattern during foraging and feeding of the leafhopper Psammotettix alienus in the presence of the spider predator Tibellus oblongus. Leafhoppers delayed feeding and fed much less often when spider was present. Foraging movement pattern changed under predation risk: movements became more frequent and briefer. There was considerable individual variation in foraging movement activity. Those individuals that increased movement activity in the presence of predator exposed themselves to higher predation risk. Whereas, individuals that survived gave a more ‘cool headed’ reaction to spider presence by moving less than leafhoppers moved in control trials. No leafhoppers were preyed upon while feeding. We term delaying feeding as a “paradoxical” antipredator tactics, which is not necessarily an optimal strategy against a sit-and-wait generalist predator.