358 



ELEMENTARY ENTOMOLOGY 



The sides of the tray are made of light six-inch boards, and the 

 bottom is formed by a piece of cheesecloth. Four-inch strips are 

 next tacked to the top of the tray, so that they project inward 

 around it. The inside of the projecting ledge formed by the four- 

 inch strips is coated with tanglefoot. The food and the larvae are 

 placed in the tray on the cheesecloth. The larvae are easily ob- 

 served all the time, and the food material may be quickly changed, 

 while the tanglefoot prevents the escape of the larvae. The larvae, 

 however, are not protected' from parasites, and the pupae must be 



removed and placed in 

 tight cages before the 

 adults emerge. 



Aquatic larvae and 

 nymphs may be reared 

 in any suitable aquarium 

 (Fig. 495), but only 

 larvae of the same size 

 should be kept together, 

 and care should be taken 

 to separate those which 

 are predacious upon one 

 another. 



Numerous cages for the study of special insects have been 



devised, as the Comstock root-cage, devices for studying the life 



history of ants, the limb cage for rearing insects out of doors in 



their natural habitat, and the breeding cage for parasites (Fig. 496). 



For further methods, consult the following books : 



L. O. Howard, The Insect Book. (Doubleday, Page & Co.) 

 W. J. Holland, The Moth Book. (Doubleday, Page & Co.) 

 V. L. Kellogg, American Insects. (Henry Holt and Company) 

 J. H. and A. B. Comstock, Insect Life. (D. Appleton & Co.) 



FIG. 496. Breeding cage for parasites 

 (After Banks) 



