life history traits of melon ladybeetle, epilachna chrysomelina (col.: coccinellidae), on four host plant species

melon ladybeetle, epilachna chrysomelina (f.), is one of the key insect pests of cucurbit crops in asia and north africa. the development and reproduction of e. chrysomelina were studied on watermelon, snake cucumber, cucumber and melon under laboratory conditions. mean total life cycle from egg to adult female was 21.3, 21.7, 26.0, and 21.3 days on the mentioned host plants respectively. mean immature mortality was 70.12%, 77.00%, 76.99% and 79.89% on the same four host plants. the female of e. chrysomelina oviposited means of 212.90, 377.85, 168.00 and 194.00 eggs and had a mean longevity of 28.77, 48.00, 38.55 and 28.36 days on watermelon, snake cucumber, cucumber and melon respectively. the net reproductive rate was 34.85, 48.82, 22.33 and 17.39 and daily intrinsic rate of increase was 0.095, 0.103, 0.073 and 0.077 on the respective plants. life table statistics showed that snake cucumber was the most suitable host plant for e. chrysomelina, followed by watermelon and melon, with cucumber least suitable.