Male mate guarding increases females' predation risk? A case study on tandem oviposition in the damselfly Coenagrion puella (Insecta : Odonata)

To estimate whether male mate guarding alters the predation risk for female s, we conducted experiments in field cages with the damselfly Coenagrion pu ella. We experimentally compared the risk for females ovipositing solitaril y versus in tandem with the male. The backswimmer Notonecta glauca was used as a predator. Owing to the oviposition behaviour of the damselflies, N. g lauca only preys on females, therefore it was possible to determine whether the presence of males decreases or increases females' predation risk. Fema les in tandem were more frequently touched and grasped by N. glauca than so litary females. In most tandem pairs, the female showed the first reaction to the attack and the male responded subsequently. After an attack, most so litary females left the oviposition site but most tandem females stayed. On ce grasped by the predator, more solitary females were killed.