State Agricultural Society. 
529 
single very distinct nut brown line, which, upon the fore wings, is a little thicker and 
slightly flexuous and is bordered on its hind side with lilac gray, which color some¬ 
times shows a faint slender brown line along its hind edge, parallel with the preceding 
one. Back of the line across their middle the hind wings and the inner part of the 
fore wings are lilac grayish with the hind border orange. The legs are rather short, 
the thighs varying in color from orange to pale violet yellowish; the shanks and 
feet are gray-green in the live insect, fading to gray in the dried specimens, freckled 
sparsely with black atoms, their exterior side being blackish. The hind shanks are 
longer and much thicker than the thighs, and have two pairs of long stout spurs. 
The feet are distinctly five-jointed, the joints cylindric and successively shorter and 
diminishing in thickness. 
The colors and markings of some specimens vary from the description above given. 
The fore wings sometimes have all their surface back of the band darker, of a red¬ 
dish lilac color, thus corresponding with the hind wings. In the female specimen 
before me the blackish lines crossing the wings are widened to double their thickness 
in the males and are of a paler or brown color with their edges indistinct. The 
female figured by Herrich Schaffer appears to have had the second line on the fore 
wings wholly effaced. 
This is a rare insect and it is probably impossible for it to become 
so multiplied as to occasion any material injury. Should there be a 
few clusters of its larvae upon the lilacs in a particular neighborhood, 
notwithstanding the manner in which they disguise themselves, some 
bird would discover their real character, and they thereupon would all 
be speedily found and destroyed. I placed a cluster of eggs which were 
beginning to hatch, in contact with a leaf of a lilac bush. The infant 
worms thereupon were watched day after day for about a week, when 
they all abruptly disappeared. Some bird had undoubtedly discovered 
and destroyed them. I regretted the loss but little, thinking that as 
some fifty worms in the flock of the previous summer had matured 
and buried themselves in my grounds, one or more broods from them 
would in all probability soon appear upon some of the lilac bushes 
in the yard. But I was disappointed. They nowhere showed them¬ 
selves. The birds had probably learned the disguise which they 
assumed; this disguise thereupon ceased to be a safeguard, and the 
whole progeny from the previous year’s flock of worms was destroyed 
it is most likely when but a few days old. 
These facts indicate by what a very precarious tenure it is that 
this species holds itself in existence. Wherever a few families of its 
young show themselves, they are discovered by the birds and are 
immediately exterminated. Thus it seems to be only in a locality 
here and there, where the birds from not seeing any of these worms for 
some years, have forgotten the mask which they put on, that a flock 
of them is able to elude their inveterate foes and grow up to maturity. 
And thus a season will sometimes arrive when a vigilant collector 
[Ag.] 67 
