Aggregating Behavior During Oviposition in the Dragonfly Sympetrum vicinum (Hagen) (Odonata: Libellulidae)

Abstract

Abstract This study examined the adaptive significance of ovipositing near conspecifics by pairs of the dragonfly Sympetrum vicinum. Studies were conducted at two artificial ponds in New York using a series of 1 m2 plots along their shorelines. Although the majority of pairs oviposited alone, pairs also tolerated the presence of others only 5–10 cm away, and sometimes 2–7 pairs oviposited together within a single plot. Habitat selection (preference for certain plots over others) partially accounted for such behavior. However, where adjoining plots were homogeneous (i.e., used equally for oviposition), newly arriving pairs were more likely to begin dipping in a plot in which one or more pairs were already present, thus also suggesting mutual attraction among pairs. Oviposition efficiency (measured as no. abdominal dips/s) was apparently not compromised by ovipositing near conspecifics. Harassment from unpaired males had little effect on oviposition since unpaired males were uncommon and rarely approached p...