272 
HALF HOURS WITH INSECTS. 
'Packard. 
dally created to gain their livelihood by preying upon 
them. 
One of the most striking cases of mimicry is afforded by 
the caterpillar of the Tolype Velleda , as well as that of its 
ally, the lappet moth, which is found on apple trees, and 
would easily, when at rest, be mistaken for a swelling or can¬ 
kered spot on the bark (Harris’ Treatise on the Injurious 
Insects of Mass., 1862, p. 379). Miss Dix, as quoted by 
Harris on the same page, states that “ when at rest the re¬ 
semblance of its upper surface was so exact with the young 
bark of the branch on which it was fixed, that its presence 
might have escaped the most accurate investigation; and 
this deception was the more complete from the unusual 
shape of the caterpillar, which might be likened to the ex¬ 
ternal third of a cylinder. The sides of the body were 
cloaked and fringed with hairs. It was of a pale sea-green 
color above, marked with ash, blended into white; and 
beneath of a brilliant orange, spotted with vivid black. 
When in motion its whole appearance was changed; it ex¬ 
tended to the length of two inches, and two-thirds of an 
inch in breadth, its colors brightened, and a transverse open¬ 
ing was disclosed on the back, two-thirds of an inch from 
the head, of a most rich velvet-black color. It was sluggish 
and motionless during the day, and active only at night.” 
The gray color and roughened surface of many longicorn 
and Buprestid beetles which rest in the daytime on the bark 
of trees are undoubtedly protective, though why multitudes 
of these two groups of insects are, on the other hand, 
among the most highly colored and brilliant of any in exis¬ 
tence, needs further investigation. Mr. Wallace observes 
that these brilliant beetles would not be eaten by birds on 
account of their very hard, dense tegument, but this will 
equally apply to the gray and dull colored species, which are 
evidently protected by these adaptive colors. The bright 
colored species are the exception in the temperate regions, 
