218 PYRAUSTID. 
parts of the upper surfaces of the leaf, not touching the 
harder and more fibrous frame-work of the same. In ex- 
treme cases this green substance has been so thoroughly 
removed by the jaws of the worms that nothing remains 
but the semi-transparent epidermis below and the net-work 
of veis; in most cases, however, a little of the parenchyma 
is left, which assumes a bright russet-red color. The cater- 
pillar always covers the leaf with loose silken threads, with 
which are mixed the minute grains of the gunpowder-like 
excrement; below this covering 
it is protected and here it feeds 
singly or in groups; in the latter 
case a number of leaves are 
drawn together to give addi- 
tional shelter. The caterpillar is 
pale-brownish, about half an 
inch long, and marked with four 
conspicuous black shining tuber- 
cles, with a pale basalannulation 
near the head. The pupa is 
Fig. 206.—Canarsia Hammonai generally formed among the 
enlarged; bon jointstill moreen. leaves in a very slight cocoon; it 
Ded ake LD Cate is of a pale brown color and 
about a quarter of an inch long. In confinement the cater- 
pillars go below the surface of the ground, and in this case 
they cover their cocoons with grains of sand. The insect 
hibernates in the pupal state. The insect is shown in Fig. 
206. | 
The strangely marked moth has the fore-wings of a 
deep, glossy, purplish-gray, marked with two silver-gray 
transverse bands. 
This insect is also preyed upon by a number of parasites, 
which in Minnesota seem to be able to keep it well in check. 
A little of the arsenical poisons used in time will prevent in- 
juries, especially in our nurseries, where the insect can be- 
come a decided nuisance. 
