90 
grows to its full size, being after the long enforced fast much 
more voracious than during the previous season. This great 
appetite is soon felt by the plants; many ‘canes with flowers 
and partly expanded foliage show by their small leaves and 
their yellowish appearance that they are suffering from the 
insidious enemy in their interior. Most of the canes attacked 
soon die, and are broken down by the first wind or heavy rain; 
the larger ones may remain alive for another year, but are 
certain to die later, as a hole through which the winged borer 
has issued permits the entrance of rain, and this moisture, in 
combination with parasitic or other fungi, soon starts decay, 
as may be seen by the black interior of such tunnels. 
The larva, when full grown, prepares for pupation by first 
eating a hole through the cane, so as to permit the future 
moth to escape. If this were not done the moth, which has no 
mouth, or at least only a rudimentary one, and which is conse- 
quently unable to eat its way out of the cane, cuvuld not leave 
at all. After providing for such an exit this hole is slightly 
closed from within with bits of wood, and now the larva 
changes to a chrysalis or pupa, as is shown in the illustration. 
The pupa is of a light brown color. In the illustration an 
- empty one is shown projecting from the hole or exit prepared 
by the caterpillar. The peculiar spines enabling it to move 
are also Shown. ‘The two long processes seen in the illustra- 
tion are simply the sheaths in which the long antennz were 
hidden. Before the moth issued these were soldered to the 
sides of the pupa, and were not more prominent than the 
encased wings and legs. 
Towards the end of May or during June, according to the 
climatic conditions prevailing at the time, the pupa forces its 
way partly out of the tunnel of the cane and pushes away the 
plug closing the exit. This movement of the pupa is made pos- 
sible by the rows of spines found upon its abdominal segments. 
The pupa is now partly outside of the cane and is held in posi- 
tion by its posterior portion. It now splits open in the usual 
manner upon its back and the winged moth appears. 
To this account of the life-history of this injurious borer may 
be added that no parasites have as yet been discovered in Min- 
nesota. Yet several times a silken cocoon was found in a tun- 
nel which apparently had been recently inhabited by a borer. 
The small wasp issuing from this cocoon is distinguished by 
