Nezara is a genus of world-wide distribution and has been represented in Japan by two species, N. antennata SCOTT and N. viridula (LINNÉ), both of which are well known pests of soy been and other various cultivated crops. This genus is considerably related to Glaucias, Palomena and Plautia, which frequently attack fruit-trees and vegetables. There are six species belonging to the above three genera known in Japan. Among those species, Nezara antennata SCOTT and Plautia ståli SCOTT have already been reported on their larval stages by ISHIHARA (1950) and by the author (1956), but Glaucias subpunctatus (WALKER), Plautia splendens DISTANT, Nezara viridula (LINNÉ) and Palomena angulosa (MOTSCHULSKY) have not been studied yet. In the present paper, the developmental stages of the last two species, together with their ecological notes, are described.<br>The diagnoses of the Genus Nezara<br>Egg: Cylindrical, with gently curved operculum and vertical wall somewhat thickened in the upper margin. Uniformly pale yellow or pale greenish yellow at an early stage. Chorion white and levigate, without particular structure on surface. Micropylar projections white, rather short, capitate. T-shaped egg-burster light brown or blackish brown, well-chitinized, arms thinly depressed laterally, membraneous appendages mostly transparent except light grayish brown lateral portions or bordered with extremely light grayish tinge infero-laterally. Egg-mass usually consisting of about 50 to 70 eggs which are deposited on the under-surface of host plant leaves, forming a rather regular hexagon.<br>Larvae: Body not so much depressed. Stigmata placed interior to the connexiva of second to eighth abdominal segments, those on eighth conspicuously smaller than others. The first instar larva bears dorsally a large, round, orange yellow or pale yellowish brown marking extending from vertex to metanotum. The second to fifth instar larvae bear several conspicuous, large or small, round or oblong, orange yellow or white markings adjacent to postero-lateral margins of dorsal plates. A comparatively large, oblong white marking interior to the connexiva of the first and the second abdominal segments and a round white marking interior to each connexivum of the third to the seventh or to the eighth abdominal segments.<br>Key to the species of the Genus Nezara<br>1 (2) In he egg before hatching, red eyespots and dark egg-burster visible through operculum. Egg-burster mostly light brown, membraneous appendages translucent except light grayish brown lateral portions. A large round pale yellowish brown marking extending from vertex to metanotum in the first instar larva. The antero-lateral margins of pronotum of the fifth instar larva not so much curved as an arc of circle, posterior angles more or less protruded laterally beyond the anterior angles of mesonotum. ………Nezara antennata SCOTT<br>2 (1) In the egg before hatching, in addition to eye-spots and egg-burster, a large reddish trapezoid marking clearly visible through operculum. Egg-burster mostly black, membraneous appendages mainly translucent, bordered with extremely light grayish tinge infero-laterally. A large round marking extending from vertex to metanotum of the first instar larva orange yellow. The antero-lateral margins of pronotum of the fifth instar larva strongly curved as an arc of circle, its posterior angles not projecting laterally beyond the anterior angles of mesonotum. ………N. viridula (LINNÉ)<br>The diagnoses of the Genus Palomena<br>Egg: Elliptical, upper part of which is more or less bigger than the under part. At an early stage, the eggs are entirely pale greenish, but later, towards the hatch, eye-spots and egg-burster become visible through the chorion. Chorion whitish