EXPLANATION TO PLATE II.

Fig. 3. PEMPTIGUS POPULI-MONILIS: a, winged female; b, her antenna; c, her antenna at birth; d, same after first molt; f, her tarsus; e, her issue at birth, ventral view-all enlarged; g, leaf showing galls-nat. size.

Fig. 4. HORMAPHIS SPINOSUs: a, gall-nat. size; b, winged female (the left wings showing abnormal venation); c, her tarsus; d, her antenna; h, frontal tubercle, as seen at birth; e, her issue at birth, ventral view; f, granulated surface of same; g, antenna of same-all enlarged.

Fig. 5. PEMPHIGUS POPULI-TRANSVERSUS: a, gall from side; b, same from beneath-nat. size; c, winged female (wings on left side detached); d, her antennaenlarged.