486 Phylum Arthropoda 



the cages or grown with the wheat. Mating took place in the cage and 

 the females oviposited freely on the growing wheat stems. The female 

 usually chooses the largest and healthiest stems in which to oviposit. 



Bibliography 

 Rncs, D. T. 1926. J.Agric.Res. 32:277. 



Reference 



Family Crabronidae 



For the rearing of Crabro see p. 517. 



Families diprionidae and tenthredinidae 



A METHOD OF BREEDING SOME DEFOLIATORS 



S. A. Graham, University of Michigan 



IN REARING various species of defoliating insects, it has been found 

 that the greatest success has almost always been attained by placing 

 the insects under as nearly natural conditions as possible. Rearing on the 

 living tree, in such a manner that an adequate supply of suitable food is 

 always available, usually works out well for the feeding stages. When, 

 however, it is necessary to use cut foliage, it is essential that it be kept 

 green by placing the cut ends of the branches in water, and by providing 

 fresh foliage every day or two. If kept under cover, the insects should 

 be provided with necessary water by sprinkling a little on the food 

 each day. In the open this need is usually satisfied automatically by 

 rain and dew. Many adult insects require drinking water even though 

 they do not eat. Therefore it is always best to sprinkle a little water 

 daily in all cages kept in the laboratory or insectary. 



THE LARCH SAWFLY, LYGEONEMATUS ERICSONII 



This technic for handling the larch sawfly has proved very satis- 

 factory and has made possible the maintenance of the insect for genera- 

 tion after generation. 



Oviposition. Because this insect will oviposit only on newly expand- 

 ing shoots of larch, it is necessary to confine the females on such suit- 

 able developing shoots. The best results were obtained when they were 

 caged on living trees. For this purpose wire cylinders about 1% inches 

 in diameter and 6 or 8 inches in length were used. After the shoot to 

 be enclosed was inserted in the cylinder the proximal end was closed 

 with a split cork, appropriately notched on the split surfaces to admit 

 the stem. 



The insects were then placed in the cage, and the distal end closed 

 with a piece of cloth fastened with a string and made doubly safe by 



