Kanskje finner vi svaret her:
Predators [edit]
Gerrids, or water striders, are preyed upon largely by birds and some fish. Petrels, terns, and some marine fish prey on Halobates.[9] Fish do not appear to be the main predators of water striders, but will in cases of starvation. Scent gland secretions from the thorax are responsible for repelling fish from eating them.[12] Gerrids are largely hunted by birds of a wide range of species dependent on habitat. Some water striders are hunted by frogs, but they are not their main food source.[12] Water striders are also sometimes hunted by each other. Water strider cannibalism involves mainly hunting nymphs for mating territory and sometimes for food.[9] To escape predators, water striders will either fly away to a neighboring pond or dive under water. This avoidance of predation aids the dispersal process and thus spread of a species over a larger area of land. As species encounter new areas of land, they must learn to adapt to new environments. There are so many species of water strider partially as a result of this dispersion and adaptation over time.[13]
Jens