SANBORN : KANSAS APHIDID^. 61 



densis) . It is gregarious and colonizes the terminal twigs, 

 often killing them with its secretions, which choke the stomata 

 of the leaves. There seem to be two varieties of this aphis on 

 the same host-plant. 



A form has been described by Fitch which colonizes the ven- 

 tral side of the leaves of the elder, but since I have found two 

 forms on the same plant, it is difficult to tell which is meant 

 from his meager description to be samhucifolix . However, I 

 shall give this form Linn's determination, and the other form, 

 shown on plate XIX, figure 91, Fitch's determination. Thomas 

 supposed the two names to be synonymous, but he had neither 

 of the species at hand from which to determine the proof of his 

 statement. 



Syphocryne avenae Fabr. Plate VIII, fig. 49. 



Head dark. Antennae light brown, and hirsute; length of 

 segments: I, 0.05 mm. ; II, 0.07 mm.; Ill, 0.07 mm.; IV, 0.23 

 mm. ; V, 0.21 mm. ; VI, 0.09 mm. ; VII, 0.29 mm. ; total length, 

 1.21 mm. Sensoria of the third about eight, sometimes in a 

 single row ; none on the fourth ; on the fifth the usual one near 

 the distal end ; six small ones around a large one near the 

 unguis of the sixth. Eyes black ; ocular tubercles tinged with 

 red ; ocelli present but not prominent. Beak concolorous and 

 extending to the third coxa, being 0.72 mm. long. 



Prothorax light brown, with a dark cephalic border. The 

 lateral tubercles are quite conspicuous, although the prothorax 

 is short. Thorax dark brown. Wings slightly brownish, 

 veins light brown. Stigma of a lighter brown, 0.14 mm. wide 

 and 0.61 mm. long. Total expansion of wings, 4.89 mm. 

 Legs light brown, except the articulations, which are darker; 

 all rather finely hirsute. Metathoracic legs are long in propor- 

 tion to the others. 



Abdomen brown, lateral margins somewhat tuberculate ; four 

 or five black spots on each lateral margin. Honey-tubes black, 

 imbricated, and cylindrical ; the distal ends have narrow, ex- 

 pandingrims ; length, 0.27 mm. Style black and spinous, except 

 the proximal part, which is concolorous with the abdomen, and 

 the lateral boundaries, which are concolorous with the distal end. 



This form was taken April 16, on the apple tree. It is grega- 

 rious, and colonizes the terminal buds and tender stems, also 



