22 CALOSOMA SYCOPHANTA. 



The beetles can be reared with fair success after some experience 

 has been obtained in properly handling them. The food supply is 

 one of the problems that causes considerable difficulty, especially 

 early in the spring and late in the summer. Before gipsy moth larvae 

 are large enough to satisfy the ravenous appetites of the beetles, tent 

 caterpillars have been used when it was possible to find them in suffi- 

 cient numbers, while after the middle of July larvae of the white- 

 marked tussock moth, fall webworm, or any other caterpillars that 

 could be collected have been used. 



Each season the continuous services of one man have been required 

 to collect caterpillars for beetle food, and at some times each year he 

 has usually found it impossible to bring to the laboratory enough 

 specimens to supply the demand. The amount of food consumed by 

 beetles or larvae is noted daily when the jars are examined, so that the 

 feeding and rearing records can be observed at one time. 



Owing to the carnivorous habits of the larvae it is usually necessary 

 to isolate them. This is especially true if detailed records are to 

 be kept, or if they have become nearly full-grown. Hot weather 

 stimulates their activity and appetite, and it is seldom possible to 

 keep several large larvae in the same jar during hot weather unless an 

 abundance of food is supplied, and even then some of them usually 

 succumb to the attacks of their comrades. The small larvae do not 

 attack each other so ferociously, but when some are practically 

 helpless at the time of molting they fall an easy prey to the others. 

 During the summer of 1909 and 1910, when large numbers were 

 being reared for field colonies, it was impossible to isolate each indi- 

 vidual, and as soon as hatching took place 10 to 15 were placed in a 

 large battery jar containing earth and an abundance of food. If 

 they were not allowed to remain more than three or four days before 

 removal, the mortality was relatively low. Later in the season, 

 after all the gipsy moth larvae and pupae had transformed in the field, 

 as many as 200 larvae were reared in box cages (PL V) having a sur- 

 face area of 2 by 3^ feet. The weather was cooler at that time, and 

 although a considerable number was killed, it did not render this 

 method of rearing impracticable for use in late summer. 



INVESTIGATION OF THE LIFE HISTORY OF CALOSOMA 

 SYCOPHANTA. 



One of the factors which renders this investigation somewhat 

 difficult is the length of life of the adults. Only a small amount of 

 data is available, because it is necessary to rear beetles in the labora- 

 tory in order to get the initial information. Many species of insects 

 die as soon as the females have deposited eggs, or the males have fer- 

 tilized the opposite sex, but this species, as well as others in the same 

 genus, have an entirely different habit of life. 



