Aspects of the diel feeding ecology of the odonate nymphsAnax JuniusandIschnura verticalisand the ephemeropteranCallibaetis fluctuanswere examined over a 24-h period in a small pond. Detrital material was the primary food of bothA. JuniusandI. verticalis.Aquatic insects (mainlyC. fluctuans) were the second ranking prey in the diel diet ofA. Junius, whereas ostracods were the second most important prey consumed byI. verticalis.Diet overlap betweenA. JuniusandI. verticaliswas high ([xbar] = 0.76) when detritus was considered but fell to 0.25 when detrital material was omitted. Food consumption by the odonate nymphs was highest at 0800 h and was generally lowest from 2400 h to 0400 h. Conversely, feeding activity byC. fluctuanspeaked between 2400 h and 0400 h with the least feeding occurring at 0800 h. Differences in diel feeding patterns between the ephemeropteran and odonate species may reflect predator avoidance behavior byC. fluctuans.