MALE-FEMALE MORPH INTERACTIONS IN THE DAMSELFLY NEHALENNIA IRENE (HAGEN)

Several hypotheses concerning factors that favour coexistence of femal e morphs in damselflies (Zygoptera: Odonata) invoke differential attra ction to (or harassment of) female morphs from mate-searching males. W e designed experiments to determine whether males were differentially attracted to either of two discrete female morphs in a damselfly, Neha lennia irene (Hagen). One female morph was similar in colour and patte rn to the conspecific male (''androchrome'') and the other was dissimi lar (''gynochrome''). Males were indiscriminate in their mating attemp ts. Overall, males were more attracted to gynochrome females; however, males that showed high response intensity to model males were equally likely to grasp models of the gynochrome and androchrome females. Dur ing male-female encounters in the field, androchrome females were more likely to chase males, whereas gynochrome females showed mon refusal displays. Other direct and indirect evidence suggests that gynochrome females may be greater targets of sexual aggression than androchrome f emales while at the pond's edge, but that androchrome females more oft en frequent the pond's edge. Whether or not these differences in behav iour translate into differential costs and benefits of being a particu lar morph is unknown.