8 NEW YORK STATE MUSEUM 
- blocks of forest and proving injurious over hundreds of acres. The 
snow-white linden moth, Ennomos subsignarius MHubn. 
was extraordinarily abundant on beech trees in the Catskills, de- 
foliating large areas in’ and about the township of Hardenburg. 
Both of these outbreaks are unusual, as neither of these species has 
been injurious in New York State for some years. Detailed ac- 
counts of these insects have been prepared and are given in subse- 
quent pages. 
Aquatic insects. The studies of our fresh-water insects have 
been continued. Prof. James G. Needham has completed his report 
on the work done at Old Forge, N. Y. in 1905, and the results 
are given in appendix C. ‘This report is particularly valuable on 
account of the new methods employed in ecological work of this 
character and because of its additions to our knowledge of the 
food of fish. There are in addition biological notes on a number 
of aquatic forms. This report also embodies a valuable addition to 
our knowledge of the midges (Chironomidae) by Dr Johannsen. 
Furthermore, the large amount of new matter, relating to stone 
flies (Plecoptera) and the caddis flies (Trichoptera), acquired at 
this time by Messrs Needham and Betten, has been withheld for 
monographic accounts of these groups. Professor Needham’s 
studies of the stone flies are nearly completed and they will prove 
an extremely valuable addition to our knowledge of this group. 
Dr Betten, who has been investigating the caddis flies for the past 
six years, has nearly completed his report upon these forms. The 
investigations of these two gentlemen, when published, will con- 
stitute in connection with bulletins previously issued by this office, 
an unrivaled contribution to our knowledge of the aquatic insects 
of the State, a group which is of great economic importance owing 
to its value as fish food. 
Gall midges. This group comprises among its members, sev- 
eral insects of prime economic importance, such as the Hessian 
fly, the wheat midge, pear midge and some other destructive forms. 
I*urthermore, there is every probability that some other of our 
native species may become destructive in the near future. Our in- 
vestigations have already disclosed hitherto unsuspected injuries by 
members of this group. We have succeeded in identifying several 
Kuropean forms not previously known to occur in this country. 
During the season we succeeded in rearing probably well over 100 
species, a considerable number of them proving to have been un- 
described. Appendix D contains descriptions of over 50 new 
