1 6 John June Davis 



in the case of the specimens examined. Thoracic tubercles not recogniz- 

 able in this specimen. Wing veins brownish and rather conspicuous ; vena- 

 tion variable in the one winged individual on this slide, one wing having Mi 

 (ist branch of the third discoidal) branching nearer the apex of the wing 

 than from where M3+4 branches and the other branching nearer where 

 -I/3+4 branches than the apex. Length of body 2.26 mm, width 1.15 mm, 

 length of cornicles 0.28 mm. 



Wingless viviparous female: Antennae on small frontal tubercles; seg- 

 ment III sometimes without sensoria but usually bearing i to 4 circular 

 ones near the distal end, IV with 7 to 8 circular sensoria; measurements 

 as follows : 



It should be noted that although VI filament is longest in the winged, IV 

 is longest in the wingless. Thoracic tubercles prominent. Cornicles 0.23 

 mm long. Style conical and 0.16 mm in length. Length of body 2.2 mm; 

 width 1.5 mm. 



Camera luc'ida drawings of the head, antenna, hind tibia, cor- 

 nicle and style of the winged viviparous female and antenna of 

 wingless viviparous female are shown in Plate III, figs. 54 to 58. 



57. A. lutescens Monell. 



58. A. maidis Fitch. 



A. maidi-radicis Forbes. 



Mr. Williams described both the aerial and root aphids attack- 

 ing corn as Aphis maidis Fitch. 



59. A. gossypii Glover {A. malvae Walker (Williams)]. 



" Aphis malvae Walker. No. 74. On Hibiscus in Greenhouse, 

 Lincoln, Jan. 23, 1890." 



Slide contains several wingless, all of which are probably im- 

 mature, and one winged viviparous female. 



Winged viviparous female: Segment III of antennae bears 7 to 8 cir- 

 cular sensoria in a row. Antennal measurements as follows : 



III IV V VI base VI filament 



0.261 0.155 0.179 0.106 0.293 mm 



0.261 0.171 0.179 0.106 0.277 mm 



268 



