82 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. 
ment of the ovaries found in the more primitive groups, and has 
retained in both sexual forms the beak and the ability to feed. 
This at once suggests a different line of development from, that 
taken by the Eriosomatinae, although in some of its habits the 
Hormaphidinae agrees with that subfamily. In other lines, however, 
marked differences are met with here and one of the most striking 
of these is development of aleyrodiform generations, which remain 
stationary upon the host. Such a development is never met with in 
the Eriosomatinae, although the sexual forms are much more 
specialized. 
Since many of the genera of the Hormaphidinae are gall formers, 
sensoria very similar to those met with in the Eriosomatinae are 
met with here also. Indeed the same annular sensoria found in 
the Eriosomatini are even more pronounced in the Hormaphidinae 
and the sensoria on the wing bases are prominent and often, 
numerous. 
The cornicles in the present subfamily are sometimes absent or, 
as is usually the case, reduced to mere rings. In some genera, how- 
ever, they may be elevated slightly on broad shallow cones, somewhat 
suggestive of those of Anoecia. No prominent cornicles, however, 
occur. 
In the wing venation there is often a considerable reduction 
and this shows also the specialized nature of the insects. The 
venation is comparable to that met with in the Eriosomatinae. In 
the fore wings the media is either simple or once branched, the radial 
sector, cubitus, and anal are present, but the cubitus and anal are 
often fused near their bases. In the hind wings both the media and 
cubitus are sometimes present, but often only the media remains. 
Great specialization in wax-producing organs occurs. In many 
of the forms these agree with the ones found in the Pemphigini. 
In certain aleyrodiform generations and in some sexual forms 
agglomerate glands or rather groups of small glands are seen. These 
may be arranged in different ways and often are placed about the 
margin of the insect so that it possesses a distinct lateral fringe, 
very like that of an aleyrodid. In fact some of these insects on this 
account are very often mistaken for aleyrodids. 
The sexual forms are often quite small and possess large wax- 
producing areas. Others may lack these. All, however, develop 
to normal adults. 
The habit of gall formation is very marked here. Indeed, some 
species form galls on two different species of plants, migrating 
between the two. 
u 
Characters. — Aerial forms living in galls or sometimes free upon the ho^t. The 
[mesothorax in many forms altered so that its divisions are more or less unobservable, 
the entire mesothorax often showing as only one plate. Scalelike or aleyrodiform 
