PEMPHIGUS SPIROTHEOJ;. 123 



The more normal forms are represented by the 

 figures 1,2, and 3, Plate CXII ; but in the previous 

 plate a gall is depicted which departs much from 

 the usual shape. The insects taken from it, however, 

 so well accord with Koch's and Passerini's description 

 of P. sjrirothecce, that I conclude the structure to be 

 the work of that species. 



I have compared the British insects also with those 

 sent to me from the South of France, with which they 

 well agree. 



M. Lichten stein found these coils still tenanted by 

 wino-ed females in December. He informs me that he 

 kept some of these in confinement at Cannes during 

 the winter of 1878, and that from them he bred non- 

 rostrated males and females. In another letter he 

 informed me that he had secured an egg from which in 

 the May following he hatched a female. He placed 

 her on a suitable tree in his garden and almost in;- 

 mediately she commenced her operations for con- 

 structing a gall, or its representative. Here she bred 

 her young, and later in the year these assumed wings. 



Through the kindness of this naturalist I am en- 

 abled to figure the oviparous female with her included 

 egg, and likewise the diminutive male. Both of these 

 are mouthless. The antennae of the former are very 

 simple in structure, and consist of only four articula- 

 tions. The latter insect shows the recurved male organ. 

 The sizes of these sexes are, for the former, 0*02 inch, 

 0-5 mm., for the latter, 0-013 inch, 0*3 mm. They 

 were captured in December. 



Dr. P. Low, of Vienna, also experimented Avith these 

 AphideS; and confirmed the observation that the produce 

 of the winged female is mouthless, and that both sexes 

 eventually descend into the ground for hibernation; 

 a circumstance quite in accordance with Passerini*s 

 supposition that such might prove to be their habit. 

 The egg probably is consigned to a crevice in the 

 bark of the Poplar, from which the foundress of the 

 new colony emerges in the spring. 



VOL. III. ^ 



