THE CANADIAN ENTOMOLOGIST 339 



feast is again repeated. This would have continued, I pre- 

 sume, till all but one were killed. To prevent it I placed in 

 their midst a young tadpole which had just died. For a short 

 time they seemed shy of it, such a feast was surely too good, 

 but when they closed in it was with a rush. Soon there was 

 nothing to be seen but a wriggling mass of fierce savages tearing 

 and biting at every available spot. As one secured a tender 

 morsel he would rush off with it, hoping to enjoy it in peace, but 

 only to be attacked by his neighbour. This fighting and scrambling 

 continued until the entire tadpole was devoured. Later in the 

 evening of the same day I gave them a dead minnow, and next 

 morning only the bones were left. In the meantime one would 

 occasionally succumb to the attacks of his neighbours, and my 

 stock was slowly decreasing in numbers. On June 28 I placed a 

 living tadpole in the aquarium, and there followed a savage attack 

 on it. The larvae seized it by the tail, mouth, and eyes, and every 

 available spot where a grip could be secured was tried time and 

 time again. It was not long before they succeeded in overcoming 

 the tadpole, and then followed a feast mingled with occasional 

 cannibalistic attacks. For sometime after this I continued to feed 

 them on tadpoles, and they seemed to thrive. 



On July 3rd one larva molted. This one was separated from 

 the rest, and an attempt made to rear it. The next day most of 

 the other larvae died on account of the extreme heat. The one that 

 had molted continued to thrive on tadpoles, snails or other food 

 which I gave it. It was interesting to see how readily it would 

 remove a snail from its shell by means of its powerful mandibles, 

 The flattened head made it easy to get under the shell, and the 

 mandibles did the rest. On July 24 this larva entered the soil to 

 pupate. It had evidently molted a second time, but I had failed 

 to find the shed skin, or else it was eaten by the larva itself. It 

 took a little over twenty-four hours to dig: out a large pupal cell 

 under a stone ;n the rearing-cage. Pupation occurred on July 26, 

 and the pupa resting in its cell is shown in figure 4. The adult 

 emerged on the 6th. The time of development is then as follows: 



Tune 25. — Young larvae began emerging. 

 July 3. — First molt occurred. 



