Abstract
Development, functional response and host preference of the larvae of Luciola lateralis were investigated in the laboratory (22±1°C) in order to evaluate its efficiency as a predator of Pomacea canaliculata. On the apple snail the ratio of all the surviving larvae at the 79th day after egg-rearing was 63.4%. This was lower than that on the freshwater snail, Semisulcospira libertina (86.3%), which is one of the preferred foods. The larvae utilized both snails almost evenly in all stages (instars 2nd, 3rd and 4th) under both constant light and dark conditions. Functional responses of the larvae to apple snail densities showed saturation curves in most cases. The maximum number of the apple snails, which were several days' post-hatched, consumed per day by the larvae were 0.7, 2.3 and 3.2 for 2nd, 3rd and 4th instars, respectively. A linear relationship with a high corelation coefficient was found between the shell height of the apple snail and the maximum number of snails consumed per day by the 4th-instar. From this relationship the maximum shell height of snails suitable for larval consumption was presumed to be 1.1cm.
