SELECTION AND REPRODUCTIVE SUCCESS IN MALES OF THE DRAGONFLY, ORTHETRUM-JAPONICUM (ODONATA, LIBELLULIDAE)

Reproductive success, copulation success, and mating success were meas ured for a population of male dragonflies, Orthetrum japonicum. Copula tion success explained the greatest variation in reproductive success. The proportion of copulations followed by oviposition was positively correlated with the number of oviposited eggs per mating. Directional selection on four morphological characters was estimated. The effect o f selection on correlated traits was comparable to that of direct sele ction. Directional selection varied between traits and between episode s in a single trait. The probability that the observed directional sel ection on the four morphological traits was expected under the conditi on of the selective neutrality of traits was not smaller than 5%.