A mark-recapture study of imaginal Enallagma cyathigerum (Charpentier) and Argia vivida Hagen (Zygoptera: Coenagrionidae)

A mark-recapture study of the 2 spp. was performed at Del Puerto Cyn., 120 km SSE of San Francisco, Calif., USA, and analyzed by the Jolly and Manly and Parr methods. Movements for dd of both spp. tended to be local. Recapture data for 99 were sparse, probably due to their greater movements. Morisita’s dispersion index for both sexes of both spp. showed the following sequence, from most to least contagious distribution: E. cyathigerum 99, E. cyathigerum dd, A. vivida 99, A. vivida dd. These differences were due to the greater preference of E. cyathigerum for water sites. Female E. cyathigerum showed a 1:3 ratio of blue to brown-olive morphs, but there appeared to be no assortative mate selection by dd. A significantly higher percentage of 99 was taken in tandem or copula with unmarked dd than marked ones, suggesting that mated 99 entered the water sites already in tandem or copula. Male E. cyathigerum and A. vivida lived an average of 4.68 and 3.02 days, respectively. The Enallagma life span estimate agrees well with reported estimates for other Enallagma spp.; but that of A. vivida is considerably shorter than for reported estimates for other Argia spp.