Effects of temperature and predator:prey ratio on feeding rate in larvae of Atherix lantha Webb (Diptera: Athericidae)

Abstract

Predator:prey experiments were conducted in the laboratory using snipe fly (Atherix lantha Webb) larvae as predators and hydropsychid caddisflies (Cheumatopsyche spp.) as prey. The effects on feeding rate of two different temperature regimes (20 and 10 °C) and five different predator:prey ratios (3:1, 2:1, 1:1, 1:2, 1:3) were tested. The number of caddisflies consumed per A. lantha larva per day was significantly greater at 20 °C than at 10 °C for the 2:1, 1:1, and 1:2 ratios (2×, 7×, and 2× greater, respectively). There were no significant differences between the 20 and 10 °C treatments at either the 3:1 or 1:3 ratio.