STATE AGRICULTURAL SOCIETY. 
609 
stant succession of new individuals are coming forth as the old ones disap¬ 
pear, through the whole season. They are committing their eggs to the 
bark of the different trees to which they resort, we suppose, at all times. 
And when the young fruit comes forward, its pulp furnishing a more ten¬ 
der and delicate repast to their young than the bark does, they for a time 
eagerly resort to it, to deposit their eggs therein. When the cold of au¬ 
tumn arrives it overtakes them in all stages of their growth. Some of 
the beetles newly hatched and with their stock of eggs not disposed of, it 
is probable crawl under stones and clods of earth, or among fallen leaves, 
or in the crevices of the bark of trees, and similar sheltered situations, and 
there lie torpid during the winter, as do many other species of the weevil 
family, to come out upon the first warm days of March and April. Others 
it is probable, when cold weather arrives have recently entered the ground 
to pass their pupa state. These pupa will remain in the ground through 
the winter awaiting the warmth of spring to enable them to complete their 
transformations. Others still are in their larva state, in all the different 
stages of their growth, in the bark, as wc suppose, and also in late ripen¬ 
ing thorn-apples, as we know. I may here state a fact which has not yet 
been mentioned. After the frosts of autumn have become so severe as to 
suspend all insect life for the season, the ground beneath some of our 
thorn bushes is found covered with fallen fruit, in which curculio worms 
are sometimes met with, these worms being then of all sizes. Such worms 
will no doubt remain torpid in the fruit through the winter, and awake to 
life the following spring, when, those that are full grown will probably 
enter the ground and complete their transformations, and those that are 
small will probably perish, as the fruit after having been frozen will scarcely 
nourish them onwards to maturity. 
In view of the fact that our injurious insects are usually restrained from 
becoming excessively multiplied by their parasitic destroyers—other insects 
which are their most inveterate foes — you will be inclined to enquire, why 
do not the destroyers of the curculio fulfill their office better, and prevent 
it from being so exceedingly numerous and destructive. 
This brings me to remark, that notwithstanding all the observations that 
have been made upon this insect, no other insect has ever been discovered, 
destroying this species and repressing its numbers, till within the past six 
months a species of this kind has been brought to light. 
Mr. D. W. Beadle, of Saint Catharines, Canada West, sent to the 
Country Gentleman, specimens of a small four-winged fly, the history of 
which, as given in an accompanying letter, was as follows: — 
Early in June, observing numerous worms in the young black-knot 
excrescences on the plum trees, he placed several of these excrescences in 
a jar of moist sand, tieing some thin muslin over the top of the jar. Early 
in July, curculio beetles began to make their appearance in this jar, and 
about a fortnight later, these flies began to appear in the jar also, and spe¬ 
cimens of both the beetles and the flies continued to come out, till the 10th 
of.August, the date when this letter was written. He suspected it to be a 
[Ac. Trans.] 30 
