OF WASHINGTON, VOLUME XVIII, 1916 13 



Described from two examples, one in a collection of thin ecu 

 adults made May 30, 1905, at Laurel, Md., and the other in a col- 

 lection of seven adults, made on June 2, 1907, at Washington, !).('., 

 both upon grape. 



Myzus persicae Sulz. 



Color green, very similar to that of the apterous form; antennae with 

 the same measurements as those of the alate, but without the row of promi- 

 nent sensoria found on the third segment of that form (the right antenna 

 of one individual has one sensorium) ; ocelli. absent as in the apterous fe- 

 male; wings reduced in one specimen to a little more than half the normal 

 size with indications of some of the veins, in the other specimen small pad- 

 like structures; alate thoracic characters absent in the specimen with the 

 smaller wings and but little indicated in the other; alary muscles much 

 reduced in both specimens, in the one, at least, showing almost the exact 

 condition met with in the aptera; cauda elongate like that of the alate 

 form. 



Described from two individuals taken on cabbage in the plant 

 houses, Vienna, Va., February 5, 1915. One of these was isolated 

 and produced j r oung in the normal manner. Other intermediates 

 of the species were observed, but were not obtained for description. 



Aphis malifoliae Fitch. 



General appearance, color, etc., resembling that of the apterous form. 

 Alate thoracic characters absent; wing represented by small pad-like 

 structure 0.32 mm. long in one specimen and 0.16 mm. long in the other. An- 

 tennae of about equal proportions in both specimens, though one is smaller 

 than the other. "Segment III, 0.576 mm.; IV, 0.352 mm.; V, 0.288 mm.; 

 VI, base 0.112 mm.; unguis 0.576 mm. One specimen has six sensoria near 

 distal extremity of III, fifteen on IV, and three on V. The other specimen 

 lias both antennae with the following sensoria, thirty- two and thirty-eight 

 on segment III, seventeen and twenty-one on IV, three and four onV. 

 Cornicles in one specimen 0.4 mm. long and in the other 0.448 mm. 



Described from two specimens reared during the spring of 1914. 

 Aphis prunifoliae Fitch. 



General appearance and color approaching that of the apterous form. 

 Antennae of first specimen as follows: III, 0.24 mm. long, and armed with 

 nine sensoria; IV, 0.112 mm. and armed with two sensoria. Segment V, 

 base 0.064 mm. unguis, 0.336 mm. This segmentation of the anlemr.ie 

 is characteristic of many of the summer apterous forms. Alate thoracic 

 characters absent; \\ings represented by pads about 0.3 mm. long. In 

 the second specimen are more typically alate being as follows: Segment 

 III, 0.272 mm. long and armed with eleven sensoria; segment IV, 0.1 Js 



