BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [8] 



of the stream behind some sheltering rock or log, place the cage there 

 and build miniature rocky rapids inside it. In quiet waters no such 

 precautions are necessary, but where the rise and fall of the water level 

 is great it may be necessary to move cages sometimes. In general, it is 

 better to hide the cages among vegetation, away from the eyes of the 

 untutored and irreverent. For aquatic insects which pupate on land a 

 cage is easily i^lanted half in the water and half out. 



Nymphs placed inside will readily crawl up the sides to transform. 

 Young imagoes should be taken out as soon as convenient after trans- 

 formation is completed (otherwise some will fall into the water and die 

 before they are mature) and placed in paper bags with their exuvise 

 until dry and well colored. 



Collectors will find it convenient to have cages of this sort made up 

 in "nests" to fit one inside the other, the size of the mesh decreasing 

 with the size of the cage. A nest of a dozen such cages and covers 

 will be found a slight transportation incumbrance. 



One may wish to take nymphs far from their natural habitat and to 

 rear them at home with no streams or ponds near. A simple breeding 

 cage that may be used successfully under such conditions consists of a 

 rough wooden kit, or pail, or tub, or half barrel, with a loose screen 

 cover. It must be rough inside, so that the nymphs can crawl up its 

 sides. It should be half filled with water, the nymphs put in, and some 

 trash with them for them to cling to, the cover added, and the whole 

 set in a place where it will not get overheated and yet will receive the 

 direct rays of the morning sun. Conditions will be less natural in such 

 a cage as this, but if only nymphs which are well grown and require 

 little or no food are put into it, it will be found entirely satisfactory. 



A very satisfactory way to rear some of the smallest and most deli- 

 cate species of dragon flies and may flies, species requiring well aerated 

 water, is to place the nymphs in shallow, flaring dishes of unglazed 

 pottery before an open screened window in one's room. The water will 

 need to be renewed daily or oftener, because of the rapid evaporation, 

 but it will keep very sweet; and the imagoes emerging will go at once 

 to the screen and stay there, and the danger of their falling into the 

 water before maturing and dying is obviated. 



COLLECTING IMAGOES. 



The easiest way to get good specimens of the largest dragon flies is 

 to rear them. It is idle to run after them with a net; but one may 

 observe sometimes that they are flying ui3on a regular "beat" and may 

 so station himself that they will once in a while come within reach. 

 When a favorite resting place is discovered, one may wait beside it 

 sometimes to good purpose. After a noonday shower specimens are 

 frequently to be picked by hand from low bushes near the water, and 

 at dusk, also, some of the large species may be found settled for the 

 night in such places, though most of them settle so high as to be out of 

 reach. 



