[ 458 ] 38 



remedy for thein is the fumes of tobacco. It is a good i)lan to apply 

 the tobacco-smoke two or three successive days, as one exposure to it is 

 often found to stultify without killiug the insects. 



Second. The tici<j-lice, comprising the several species of the genus 

 Lachnus. These aie disfinguished by their six-jointed anteunfe, the 

 honey-tubes .very short or merely rudimental, and by their usually 

 dotted abdomens. These are found in flocks on the smaller limbs of the 

 hickory, the willow, and probably other trees. We have seen them on 

 youn^- ai)])le trees, but in this instance it was evident that the}' had mi- 

 grated thither from some neighboriug willows. With this accidental 

 exception we believe the species of this genus have not been found on 

 any of our fruit trees. 



Third. The root-lice^ belonging to different genera, with the an- 

 tennae still shorter, and the honey-tubes wholly wanting. These infest 

 the roots of plants, often causing their death, and they are therefore 

 much more serious pests than any of the other kinds. The root-hce 

 which infest the roots of young apple trees {Eriosoma Pyri) and those 

 found upon the roots of the grape \i.ne, {Fliylloxera vitifoUi,) are the 

 most important species in this section. Both of these species are much 

 more abundant in the southern than in the northern half of the State. 

 The best preventive of the spread of these insects is to examine the 

 roots of young trees or vines when taken up for the purpose of trans- 

 planting, and if found to be infested by the root lice, to immerse them 

 for a few minutes in hot soapsuds or tobacco water. The presence of 

 the lice is often first detected by the swellings or knots upon the roots 

 which the lice produce. 



Fourth. The gaU-lice, or more definitely, the gall-making Aphides, for 

 galls are also made by other insects, to some of which, especially the 

 gall making Acari or mites, the term gall lice would be still more appro- 

 priate. 



To this section belongs the species which is the subject of this article. 

 It is evident that gall insects, like those which inhabit the substance of 

 our fruits, must be very diflicult to contend with, for the reason that our 

 destructive applications cannot ordinarily be made to reach them, and 

 yet, if we carefully trace the history of almost any noxious insect through 

 its whole career, we can generally discover some one more weak or ex- 

 posed points in which they become subject to destructive agencies. 



Fortunately the gall-making Aphides have not as yet seriously infested 

 any of om^ fruit bearing trees, with the exception of those found on the 

 leaves of the Clinton grape vine. Galls in great diversity render un- 

 sightly the foliage of many forest and ornamental shade trees, but as a gen- 

 eral rule they are not sufficiently numerous to interfere materially with the 

 health and growth of the trees. This rule, however, has its exceptions, 



