The Morphological Cahracters in the Nymphal Stages of Megoura viciae japonica (M_<ATSUMURA>)

Key to the instars of Megoura viciae japonica (M_<ATSUMURA>) (Wingless from) 1. Antennae are five segmented ･…2 Antennae are six segmented ････3 M. viciae japonica, as well as other species of Aphididae, has six-segmented anatennae in the adult. In the first and second instars, they have five segmented antennae. In further growth the third segment divids and adds to the number of segments. 2. Antennae with fewer setae than other instars, especially the third segment provided with only one in the middle part. The number of setae on each segment are as follows: I-3, II-5, III-1, IV-4, V-6～7.....