252 NEW YORK STATE MUSEUM 



leaviii*,' a transverse scar and a small opening. The j^rall is at first rosy, 

 then tureen and is adorned with lar<;e curved spines. The second genera- 

 tion develops within th(; gall and early in July, about six weeks from the 

 birth of the stem mother, the winged adults migrate to the birch and 

 continue there till late in the fall. The third generation is developed on 

 the leaves and later wanders to the twigs and branches. The young are 

 Coccidiform and resemble a young Lecanium and in the early stafj"es are 

 fringed with short wa.w rods. They hibernate on the twigs and on the 

 stems, where they attain full maturil). The fourth generation returns to 

 the leaves, forms pseudo-galls by sucking the fluids from the under portion 

 and causing an arching up of the areas betwt-cn the lateral ribs. The 

 young in the second stage bear conspicuous tufts of a whitt- waxy secretion 

 on the sides of the posterior segments of the abdomen. The adults of 

 these produce the fifth or migratory generation whi( h returns to the witch 

 hazel from early in July till about the middle of the month. It is much 

 like the preceding in character and is remarkable in the production of 

 accessory wingless females, parents of a seconthir)- migratory generation, 

 which in turn flies to the witch hazel. The >oung of these migratory 

 generations, wingless males and females, pair and produce the winter eggs 

 which, as previously stated, are dej'osiled between the middle of June and 

 early July. This hitler life hislor)- is fully as remarkable as that of the 

 precetllng and, as noted abo\e, it will be seen that not onl\' is there an 

 alternation of food plants and alternation of generations but there is also a 

 ])rolongetl life cycle and an extended period of nearly 1 1 months passed in 

 the winter egg. 



These two species illustrate some of the remarkable features about 

 aphids or plant lice and it is \ery probaljle that further investigations would 

 reveal other hitherto unsuspecteil relationships. It is not at all imijossible 

 that s(jme of the 325 species supposed to be disiincl, nia\' in realiu' be only 

 different forms. ()ur knowledge of the Aphididae is allogelher too limited 

 to permit the drawing of many general conclusions and the stiul)- of this 

 family both from the systematic and the biologic aspect affords a very 

 enticintr tield for the earnest conscientious worker. 



