412 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
tions, the elimination or reduction of the more favored food species 
will conform to desirable silvicultural practices. 
Behre, Cline, and Baker (27) conclude: 
Information based on averages over a period of many years and secured from 
a large number of woodland plots shows that in mixtures of hardwoods serious 
defoliation is not likely to take place where the volume of favored food tree 
foliage constitutes less than one-half the total, but, where the protection of conifers 
is involved, a somewhat greater reduction is recommended. Where conditions 
are particularly favorable for increase of the insect, it may be advisable to reduce 
still further the volume of favored foliage, perhaps even to the extent of complete 
elimination, 
Ege clusters can be destroyed by saturating them with a creosote 
mixture commercially pr epared for this purpose. 
Spraying with lead arsenate (p. 53) was for many years the most 
eifective measure for destroying the larvae. Recently, airplane spray- 
ing with DDT has proved 
to ‘be much more effective 
and cheaper. In some 
cases, particularly where 
a few ornamental and 
shade trees are concerned, 
a burlap band may be 
tied around the tree trunk 
and folded down at the 
middle of the band. This 
affords shelter for the 
larvae during the day- 
time. These bands 
should be examined fre- 
quently, and the larvae 
congregated beneath 
them destroyed. 
The Brown-Tail Moth 
The brown-tail moth 
(Vygmia phaeorrhoea 
(Donoy.) ) is pure white 
except the tip of the ab- 
domen, which is densely 
clothed with brown hairs. 
: © The female (fig. 83, 7, 7) 
FIGURE 83.—The brown-tail moth (Nygmia phae- has a rather stout abdo- 
orrhoea) —A, Winter nest; B, male pupa: C, men anda wing expanse 
female pupa : D, cocoon in leaves; #, full- of about 114, inches. while 
grown caterpillar; /, female depositing egzs 7 
; TES (OD ; 
on a leaf; G, egg mass on leaf; H, male moth; the male (fig. 83, [T) 1S 
I, female moth. All about %4 natural size. more slender and shghtly 
smaller. The eggs are 
usually deposited on the underside of a leaf in elongate ov ral masses 
1% to 34 inch in length. Each mass contains about “300 eges, which 
are closely packed and covered with brown hairs from the abdomen 
of the female (fig. 83, 7, @). 
The full-grown larv: (fig. 83, £) is about 11% inches long, the head 
is light brown, the body dark brown to almost black, with a broken 
