Io8 SECOND REPORT OF THE STATE ENTOMOLOGIST. 



kernels be pressed, the distinction can easily be made of those which 

 have been occupied for some time and those for a short time. The age 

 also of the caterpillar within the kernel, up to a certain point, can be 

 told. If the kernel yield throughout its length under the pressure of 

 the finger, it contains a caterpillar which has nearly attained its growth, 

 or the chrysalis of the caterpillar. If at only a certain part of the kernel 

 it yields to pressure, the caterpillar has not eaten the entire substance, 

 and it has yet to grow. Another means more sure, and shorter, and the 

 more readily to know the kernels attacked by these insects or by the 

 weevil, is to throw in water the wheat or barley : all the eaten kernels 

 will float. 



When the caterpillar is hatched, it is so small that a good lens is 

 needed to distinguish it ; it is not more than three lines long when ready 

 for its metamorphosis ; it is smooth and white, its head only is a little 

 brown ; it has sixteen feet, of which the eight intermediary are so small 

 as to be hardly perceptible ; the extremity appears to be bordered with 

 brown hooks, disposed as a crown. 



A kernel of wheat or barley contains just the amount of aliment for 

 the food and growth of this caterpillar until its transformation. If one 

 be opened containing a caterpillar ready for its change, only the shell 

 will be found remaining; all the farinaceous substance has been eaten. 

 But before changing into chrysalis, this caterpillar has an important 

 work to do ; it is necessary to provide an outlet which it would not be 

 able to do when it attains the perfect state. The Alucita, unprovided 

 with teeth, would never be able to pierce the outside of the kernel for its 

 escape. The caterpillar cuts circularly a piece of the surface, so that it 

 merely holds to the kernel by a portion of its circumference, of which 

 the extent is hardly equal to the diameter of a hair ; it does not, how- 

 ever, disturb this piece, so that it does not show so long as the chrys- 

 alis is contained in the kernel; it can hardly be told when the insect 

 has emerged from it. After this operation, the caterpillar spins in the 

 interior of the kernel a silken cocoon of a very fine tissue, and changes 

 into the chrysalis. It should be observed that this cocoon does not oc- 

 cupy all the excavation in the kernel — the caterpillar setting off a 

 small space in which it places all of its excrement which it was not able 

 until then to separate. 



Messrs. Hamel and Tillet have observed that these Alucitas are usu- 

 ally seen in two seasons, in the spring, as soon as the wheat commences 

 to appear in the head, and these are from the caterpillars that have 

 passed the winter in the grain ; the others appear in the summer, in the 

 neighborhood of the harvest ; these produce the eggs for the first brood, 

 of which we have spoken, and give birth to caterpillars which are to 

 produce the moths of the following year ; some of these may appear 

 during the course of the summer, but the greater part of the number 

 have exactly this order which, however, is sometimes accelerated or re- 

 tarded by the different temperatures of the air. One thing worthy of 

 remark is, that the moths which emerge in the month of May from 

 grain in the granaries hasten to escape through the windows and to 

 gain the fields ; while those which are disclosed after the harvest show- 

 no inclination to escape. It seems that their instinct informs them that 

 they will not find at that time, in the fields, that which woufd be needed 

 for the well-being of their posterity. 



