26 THIRD ANNUAL REPORT OF 



requires to undergo its transformations and issue as a beetle, this, its 

 deadly foe, gnaws a hole through its cocoon and issues to the light of 

 day as a black four-winged fly (Fig. 7, a male ; b female). In the 

 vicinity of St. Louis, this fly was so common the past season that af- 

 ter very careful estimates, I am satisfied three-fourths of all the more 

 early developed Curculio larvae were destroyed by it. On the 17th 

 and 18th of April, in that locality a severe frost killed the peach buds 

 on all but a few of the young and most vigorous trees of Hale's Early 

 and Crawford, so that instead of a large and abundant crop of peaches 

 to depredate on, the little Turk had to concentrate its attacks on the 

 few peaches that were left; and no one expected that any fruit would 

 be saved. Yet the work of this little parasite was so effectual that, 

 wherever fruit set, a fair crop was gathered even by those who made 

 no effort at all to protect their trees ! 



While visiting Dr. Fitch last August, at his house in Salem, N. Y., 

 I compared my bred specimens with his species, and found them 

 identically the same; but a full description of it will be found below, 

 and it is not necessary at present to dwell upon its characters. 



As Mr. Walsh bred this same parasite from the larvae of his little 

 Plum Moth, it doubtless attacks other soft-bodied larvae and does not 

 confine itself to the Plum Curculio. This is the more likely as it would 

 scarcely pass the winter in the fly state. The female, with that won- 

 derful instinct which is exhibited in such a surpassing degree in the 

 insect world, knows as well as we great Lords of Creation what the 

 little crescent mark upon a peach or plum indicates ; and can doubt- 

 less tell with more surity, though she never received a lesson from 

 her parents, whether or not a Curculo larva is drilling its way through 

 the fruit. When she has once ascertained the presence of such a 

 larva by aid of her antennas — which she deftly applies to different 

 parts of the fruit, and which doubtless possess some occult and deli- 

 cate sense of perception, which, with our comparatively dull senses, 

 we are unable to comprehend — then she pierces the fruit, and with 

 unerring precision, deposits a single egg in her victim, by means of 

 her ovipositor. 



Now there is, as I shall show in the description, a variety (rufus) 

 of this parasite, with the ovipositor nearly one-fifth of an inch long, 

 but in the normal form the ovipositor is only twelve-hundredths of 

 an inch long, and the Curculio larva must therefore be reached soon 

 after it hatches, or while yet very young. Consequently we find that 

 the earliest Curculio larvae, or those which hatch while the fruit is 

 yet small, are the most subject to be parasitised, and while from larva 

 obtained early in the season, I bred more parasites than Curculios, 

 this order of things was reversed a little later in the year. Some 

 persons will no doubt wonder how such a large fly can be developed 

 from a Curculio larva which is stung while so young; but we do not 

 know how long the parasitic egg remains unhatched, and it must be re- 



