2F) PAPERS ON AFHIDID.*:. 



EGG. 



The egg is elliptical, bright orange when fu'st laid, graduiilly chang- 

 ing to shining jet black, and measm'es 0.575 mm. in length by 0.248 

 mm. in \vidth. 



LIFE HISTORY AND HABITS. 



With Calliptenis tnfolii, as with most other plant-lice, a number of 

 generations of winged and wingless viviparous females are produced 

 during the sununer, and the true sexes, consisting of winged males and 

 wingless oviparous females, appear in the fall; these females in turn 

 laying eggs on the stems and leaves of clover to carry the species over 

 the winter months. Tliis species does not have an alternate host, 

 nor does it ever pass the winter, in the latitude of La Fayette, Ind., 

 as viviparous females. However, in the Southern States it probably 

 does winter as viviparous females, for Mr. Geo. G. Ainslie found the 

 viviparous forms not uncommon at Clemson College, S. C, in Decem- 

 ber (Dec. 3, 1908), whereas a careful search for sexual individuals 

 proved fruitless. Similar observations were made by Mr. R. A. 

 Vickery at Salisbury, N. C, November 11, 1909. 



As is characteristic of this tribe of plant-lice (CaUipterini) the spe- 

 cies under discussion is sporadic in habit and is very easily roused, 

 the least disturbance causing it to jump from its host. This habit is 

 much to its advantage, for it seems to render the species almost 

 immune from predaceous and parasitic enemies. 



METHODS OF STUDY. 



The life-history studies here recorded were made in outdoor shelters, 

 and the vivaria used were chimney cages such as had previously been 

 used and described by the writer for other species of aphides.* Tlie 

 outdoor shelter consisted of frame benches, placed under a canvas 

 canopy (PL II) to protect the cages and shelters from the intense 

 midsummer sun. This was necessary, for while the aphides might 

 live out of doors without spe^^-ial protection from the sun, there they 

 have the advantage of a constant circulation of ah- which is not pos- 

 sible within the glass chimney cages. 



The generation series were begun with the stem-mother hatching 

 from the winter egg, and the first and last born generation series con- 

 tinued to the true sexual forms in the fall. In this way the maximum 

 and minimum number of generations annually was obtained under 

 what might be considered optimum conditions, at least from the 

 standpoint of natural enemies and harmful cHmatic conditions. 



■ U. S. Dept. Agr., Bur. Ent., Tech. Ser. No. 12, Pt. Vm, p. 159. (See also Bui. 2.5, Pt. I. of the same 

 series.) 



