ترجیح میزبانی شب‌پره(Crambidae) Cataclysta lemnata در شالیزارهای شمال ایران

Cataclysta lemnata is an aquatic moth, which reported from some of aquatic plants worldwide. Nevertheless, species of Lemnaceae and Lemna minor L. in special, have been known as the main host plants of this moth. During some surveys, high density populations of this moth found on water fern (Azolla spp.: Azolaceae). In order to find out about preferred host plant for feeding and egg laying, two experiments were conducted under choice condition in the laboratory. In the first experiment, there were four replicates with 25 larvae and Azolla filiculoides Lam. , Azolla pinnata R. Br. and L. minor in each replicate and a control without larva that were conducted for evaluating larvae feeding preference. In the second experiment, there were 25 replicates each including one newly emerged female and two or three males and above-mentioned host plants for evaluating egg laying preference of the females. In feeding preference experiment, the highest means for the larvae existence on host plant (10±0/41 larvae) and percentage of consumed food (40±0/79%) were observed on L. minor. There was no significant difference between the larvae existence on A. filiculoides and A. pinnata. However, the percentage of consumed food on A. filiculoides (31/5±4/62%) was significantly higher than that on A. pinnata (19/8±5/41%). In the egg laying preference experiment, the mean eggs produced on L. minor (158±16/16 eggs) was significantly higher than those on Azolla spp. treatments. There was no significant difference between eggs produced on A. pinnata (43±6/28 eggs) and A. filiculoides (13±3/51 eggs). This study revealed that L. minor is preferred host plant for feeding and egg lying of C. lemnata. However, results of previous studies indicated that the moth is not able to feed on this host plant in paddy fields and have high mortality. Based on obtained results, it seems that the larvae prefer A. filiculoides as food plant more while A. pinnata is more preferred for egg laying by females. Therefore, existence of both Azolla spp. at the same time, such as the condition that is observable in aquatic ecosystems of northern Iran, would have positive effect on increasing of the moth population density