OVIPOSITION SITE PREFERENCES AND SPATIAL SEGREGATION IN 2 SPECIES OF STREAM-DWELLING WATERSTRIDERS (HEMIPTERA, GERRIDAE)

I investigated whether oviposition site preferences enhance competitiv e coexistence in two species of stream-dwelling waterstriders, Aquariu s conformis and A. remigis (Hemiptera: Gerridae). In a laboratory expe riment, I tested the hypothesis that the two species differ in their o viposition site preferences. Results indicated a highly significant di fference between A. conformis and A. remigis in oviposition site use. In comparison to a random use hypothesis, A. conformis strongly prefer red grass and A. remigis strongly preferred rocks, which correlated wi th the typical habitat in which each species is found. Differences in oviposition site preferences may reduce competition between juveniles of the two species, because juveniles remain close to the site where t hey hatched.