AbstractAnax junius(Odonata: Aeschnidae) predation on young crawfish,Procambarus clarkii, was measured in the laboratory. Predation rates (0.066–1.16 crawfish/day) were estimated at 25, 15, and 5 C and for two sizes of crawfish (11–20 and 21–30 mm total length). Naiad predation increased with increasing temperature and decreasing crawfish size. At 5 C, naiads had no significant effect on survival of large crawfish but did significantly reduce survival of small crawfish. At 15 and 25 C, predation rates were significantly affected by temperature and prey size. Relative naiad abundance in a 0.8 ha crawfish pond was estimated from September through May. Larger naiads (head width,>6.5 mm; total length,>30 mm) capable of preying on young crawfish were not present until after most crawfish had reached invulnerable sizes. Large naiads, as a result, may not affect crawfish production under normal management condi