A SYNOPSIS OF THE APHIDIDAE 57 



ferns, particularly the Boston fern. Essig has also found it on violets 

 in the vicinity of Pomona College. The alate females have the wings 

 beautifully marked with black and white. 



23. Genus Macrosiphum Passerini 

 Passerini, Gli Afidi, 1860. Type Aphis rosae Linn. 

 KEY TO CALIFORNIA SPECIES 

 Alate viviparous females 



1. Cornicles slightly clavate on one side, somewhat as in Bhopalosiphum. 



tulipae (Monell) 



Cornicles not clavate 2 



2. Ill as long as V and VI (base and spur) sonchella (Monell) 



Ill not as long comparatively 3 



3. Ill pale, IV, V, and VI dusky jasminum (Clarke) 



Not so; if IV, V, and VI are dusky then III is also, except perhaps the base; 



or if III is pale throughout then at least the greater part of IV and V are 

 also pale 4 



4. VI (base and spur) shorter than III, but V and VI together are longer than 



III baccharadis (Clarke) 



VI (base and spur) not shorter than III 5 



5. Secondary sensoria on III, IV, and V. Cornicles not reticulated. 



heucherae (Oestlund) 



No secondary sensoria on V 6 



6. Secondary sensoria on both III and IV. Cornicles with tips at least reticulated 



(fig. 152 ) 7 



No secondary sensoria on IV 10 



7. Cornicles and cauda subequal in length, the former being more or less bottle- 



shaped sanborni Gillette 



Cornicles longer than cauda 8 



8. Cauda light green. Secondary sensoria only occasionally present on IV and 



then very small and indistinct rosae (Linn.) 



Cauda dark (brown or black). Seven or more distinct secondary sensoria 



on IV 9 



9. Body with capitate setae, especially on head and antennae. 



artemisiae (Fonsc.) 



Body without capitate setae. Abdomen with dark dorsal markings. 



lactucae (Kalt.) 



10. Cornicles with at least tips reticulated (fig. 132) 14 



Cornicles with no reticulations (fig. 156) 11 



11. Body with fan-shaped setae artemisicola (Williams) 



Body without fan-shaped setae 12 



12. Distal two-thirds of cornicles black orthocarpus (Dvdn.) 



Only tip of cornicles black 13 



13. Cornicles long and slender. About 18 secondary sensoria in a row on III 



(fig. 130) pisi (Kalt.) 



Cornicles shorter and heavier. About 25 to 30 sensoria scattered irregularly 



along III (fig. 157) dirhodum (Walker) 



14. Cornicles with more than apical one-half reticulate (fig. 149). 



ludovicianae (Oestlund) 



Cornicles with less than apical one-half reticulated (fig. 128) 15 



