THE TIME OF EMBRYONIC DETERMINATION OF SENSORIA AND ANTENNAL COLOR AND THEIR RELATION TO THE DETERMINATION OF WINGS, OCELLI, AND WING MUSCLE IN APHIDS

¹ COE COLLEGE, CEDAR RAPIDS, IOWA

Dark antennal color and increased sensoria of winged aphids are considered to be characters closely correlated in development, for in general when there was a darkening of antennae there was a corresponding increase in the number of sensoria. In practically all cases increased sensoria were correlated with a relatively large amount of non-degenerate wing muscle. It is concluded that embryonic determination of dark antennal color and increased sensoria takes place in a comparatively short period of time as compared with that of wings, ocelli, and wing muscle. The data make it seem probable that dark antennal color and extra sensoria, characteristic of the winged aphid, are determined after the wings, ocelli, and wing muscle; the former, however, complete their segregation before the latter.