Group Aphidina, Family Aphididae 65 



The Lachnina are represented by two or more generalized 

 tribes of the family. Following this is the group Chaitophorina, 

 easily traced from the Lachnini by way of the Pterocommini. 

 The Chaitophorini being a parallel line from the same source ; 

 the Vacunini may be looked upon as a very specialized line, but 

 of much interest as giving us a clew to the origin of the sub- 

 family Pemphiginae. The Callipterina are a third group of tribes 

 traced not from the Lachnini, but from the Pterochlorini stock, 

 through the generalized tribe Calaphidini. The Callipterini and 

 Drepanosophini stand in similar relation to the Calaphidini that 

 the Chaitophorini and Vacunini do to the Pterocommini. What 

 may be called the modern or recent group of tribes, represented 

 by the term Aphidina, are the tribes rich in genera and species 

 in which the family has reached the maximum of evolution of 

 the present. The Lachnina represented the maximum of the 

 family during the early days of its existence, and is now a de- 

 clining or vanishing group few in genera and species in com- 

 parison with the rest of the family. During a somewhat later 

 period, the two groups Chaitophorina and Callipterina flourished 

 side by side, but were of very different origin and lines of de- 

 velopment. And lastly comes what was just called the modern 

 or recent group of tribes, the Aphidina, the peak of the family as 

 represented at present. The groups are not. therefore, arbitrary 

 terms expressing personal opinions, but are the outcome of ex- 

 tended biological and morphological studies carried on by Mord- 

 wilko and the author in the nineties, unknown to one another but 

 leading to almost identical results. When Mordwilko, therefore, 

 published his results, they were at once recognized by the writer, 

 and haA'e only been carried a step further. The group Aphidina 

 includes the three tribes Aphidini. Myzini, and Macrosiphini. A 

 key to the tribes was given in a previous contribution. 



Tribe APHIDINI (Thomas) Oestlund, 1919 



Koch. 1854. Die Pflanzeiil. Hft. 1. Sub Aphiden (tribe) 



Passerlni, 1863. Aphid. Ital. Sub Aphidinae (subfamily) 



Buckton, 1870. Monogr. Vol. 1. Sub Aphidinae (tribe) 



Thomas, 1878. Bui. 2 111. State Lab. Sub Aphidini (tribe) 



Oestlund, 1887. Bui. 4, Geol. Surv. Sub Aphidini (tribe) 



Wilson, 1910. Ann. Ent. Soc. Am. Vol. 3. Sub Aphidini (tribe) 



Van der Goot. 1913. Tijdschr. Entom. Vol. 56. Sub Siphonophorina (tribe) 



Oestlund. 1919. 17th Kept. State Entom. Minn. Sub Aphidini (tribe) 



Baker, 1920. Bui. 82(5 U. S. Dept. Agr. Sub Aphidina (subtribe) 



It will be seen from the above synopsis of the bibliography 

 of the tribe Aphidini that the conception of the tribe has varied 



