6 Bulletin 32S 



did much damage. The faihire of the usual methods of aphis 

 control when this species appeared necessitated a study of the 

 problem, and in the follovx'ing account it is attempted to set forth 

 the most important of the results obtained. 



Recognition Marks 



The stage in which the aphis is found throughout the winter 

 and early spring is a small shining-black egg fastened to the 

 bark of the twigs and smaller branches. They are likely to be 

 laid on the tender ends of water sprouts, in the depressions about 

 bud and pruning scars, or partly or completely inserted ])etween 

 the buds and the stem. The eggs of green apple aphis have in 

 our experience been more commonly found on the water sprouts 

 than those of either of the other species. 



Fig. I. First stage of the green, the rosy and the oat aphis 

 (After Parrott, Hodgkiss and Lathrop) 



The newly-hatched lice of the green, the rosy, and the oat 

 aphis are very small, dark-green in color and look much alike. 

 Parrott, Hodgekiss, and Lathrop^ have discovered differences 

 by which one species may be told from another, and Dr. Alvah 

 Peterson has found that the characters cited by them hc^ld for 

 New Jersey conditions. 



The length of the antennas, or feelers, and the size and shape 

 of the cornicles, or honey tubes, are the points that we have 

 found most useful in distinguishing the dift'erent species. 



As these young develop into wingless stem-mothers, their 

 characteristic differences become so distinct that recognition of 



'Parrott, P. J., Hodgekiss, H. E., and Lathrop, F. H., 1917. Phintlice 

 injurious to apple orchards. II. Studies on control of newly-hatched aphides. 

 N. Y. (Geneva) Agr. Exp. Sta. Bui. 43i- 



