Abstract
The authors should be able to describe the life history and the life cycle of the Anomala schönfeldti Ohaus in Iwata district which is the most injurious insect to turfgrass.
(1) The emergence of adult insects occurred from the first 10 days of June to the later 10 days of August, the peak of a large mountain-shaped curve of the emergence appeared in the last 10 days of June and that of a small curve appeared in the middle of August. The natural duration of life of the adult insects was about 20 days, the time of their coming to the earth was from 7 p.m. to 8 p.m. and the copulation and the oviposition of them occurred in this period.
(2) Hatched larvae pupated through the 3rd instar. The individuals that oviposited early became the 1st instar in July, the 1st and 2nd one in August, the 2nd and 3rd one in September, and the 3rd one in October so on. Their hibernations occurred when they became the 3rd instar, and their pupations began from the first 10 days of May in the next year. Pupal period was 16.4 days.
(3) Larvae of the 3rd instar were distingushed into the white larvae and the yellow ones. The former appeared at the period from the 1st instar to the first half of the 3rd instar and the latter were observed at the second half of the 3rd instar. White larvae lived in the shallower layer of soil where the roots of turfgrass were distributed and fed on those roots ; yellow ones lived in the deeper soil layer than that of white ones and pupated without taking roots.
(4) In case of a male, the thorax and the surface of fore wings are black and the length of antenna's club is longer than that of a female ; but the colour of a female is brown ; the lower parts of female's abdomen are bulgy and the length of club is shorter than that of a male.
