Reports on bionomical characteristics of Mellicta ambigua

ABSTRACT Recently the number of the butterflies, Mellicta ambigua, had been decreasing rapidly, and already disappeared at manyhabitat. In this studies, we investigated ecological environment of Mellicta ambigua for preparing of primary researchdata recovering habitat, and studied on bionomical characteristics. Two different habitat, Jindo and Inje, were selectedfor investigation of ecological environment. We investigated four times during 3-month, from June to August in 2012.In Jindo, we observed more than 100 butterflies and a lot of host plants, Melampyrum roseum var. japonicum. But only5 butterflies and only a few host plants, Veronicastrum sibiricum were observed in Inje. We could not observe the eggs,the larva and pupa on the host plants at all. For finding of bionomical characteritics, we reared butterflies at natural con-ditions. Collected 3-female butterflies from Jindo laid 465 eggs on the leaves of 3-host plants, Veronicastrum sibiricum.120 ~ 186 eggs per each female were laid in the shape of cluster. An egg was globular shape, 0.6 mm diameter and0.7 mm height. The egg periods were 9.96± 0.4 days after ovipositioning, and the hatchability was 95.% at natural con-dition. The larval periods were 4.1 ±0.6 days (1st instar), 2.11.0 days (2nd), 8.1± 0.7 days (3rd), 239.2± 10.9 days(4th), 12.3 ±1.3 days (5th), 17.1 1.1 days (6th), 10.5± 1.0 days (7th) each other. The larva of 4th instar overwinteredin the nest that had been made into the leaf of host plant with secreted thread as a group until early March next year.In the early March next year, overwintered larva went around their nest in search of host plants, and went to other hostplants, Veronica persica and Plantago asiatica, sometimes. The overwintered larva of Mellicta ambigua could grow upon two other host plants normally. In the following experiment, the butterflies of Mellicta ambigua laid eggs on theleaves of Plantago asiatica, but the 1st instar larva from eggs died all. The headwidth of each developmental larval stagewere 0.28 ±0.02 mm (1st), 0.45 ±0.02 mm (2nd), 0.58 0.02 mm (3rd), 0.75 0.03 mm (4th), 0.89± 0.05 mm (5th),1.23 ±0.06 mm (6th), 2.13± 0.11 mm (7th). The pupal ratio was 92.0%. The pupal period were 9.11.6 days, andthe emergence rate was 88.6%. As a result we determined that Mellicta ambigua can rear at natural conditions. Butindoor-rearing is considered to be difficult and not useful industrially, because they have long term larval stage and onlyone life cycle per an year.Key words : Mellicta ambigua, Habitat, Bionomical characteristics, Host plant, Rearing