232 



BUIvI^ETlN OF THE BUREAU OF FISHERIES. 



Ameinrus meias^ contained 6 Enallagma hageni images, and the stomach of a largemouth 

 black bass contained 22 Enallagma antennatum imagos. 



In a record made by Mr. Schradieck of the food of the largemouth black bass in 

 ponds 2 and 3 D, a fish 48 mm. in length had for its stomach contents 95 per cent damsel- 

 fly imagos and 5 per cent Chironomid larvae. Another fish, 82 mm. long, contained 

 nothing except a few damselfly imagos; a third, 65 mm. long, contained 50 per cent 

 damselfly imagos and 20 per cent ©donate eggs. 



H. L. Canfield, superintendent of fish culture at the Fairport station, told the 

 author that he had fed Anax imagos to largemouth black bass at Homer, Minn. The 

 fish seized them avariciously and apparently swallowed them, but in a moment or two 

 spit them out again. Perhaps the- Anax was too large a mouthful for them, for the 

 bass at Fairport certainly swallowed imagos of L. luctuosa, Erythemis, Plathemis, and 

 Leucorrhinia and kept them down. 



STOCKING THE FISHPOND. 



Having tried to show, it is hoped with some success, that dragonflies and damsel- 

 flies and their nymphs are not only desirable additions to the fauna of fishponds but 

 that they may even prove of considerable importance, there remains the problem of 

 obtaining a sufficient number of the right kind with which to stock a pond. How 

 can this best be accomplished ? With reference to the dragonflies several methods may 

 be suggested and briefly discussed. Embody stated in The Farm Fishpond (191 5, 

 p. 242) that after the pond has been completed and filled with water: 



The aquatic plants should be the first /Drganisms to be put into the pond * * * forage 

 animals should be collected next. As has been stated, until more is known about the propagation of 

 aquatic insects it will be impossible to give definite and reliable directions for their introduction. 

 Certain desirable forms will naturally be attracted to the pond for egg laying, and for the present this 

 natural method of propagation is the only one to be depended on. 



Of course dragonflies will be among the insects naturally attracted to the pond 

 for egg laying, but it is desired that the pond be stocked at once and witH the kinds 

 most available for forage food. The author believes that, so far as the odonates are 

 concerned, we already possess sufficient knowledge to enable us to take the initiative, 

 and not only to introduce desirable species, but also to exercise considerable control 

 over their subsequent abundance. 



Choice of DragonfIvY Species. — ^The species of dragonfly best suited to any 

 particular fishpond is not by any means necessarily the one that has been tried success- 

 fully elsewhere. The condition of the pond and its environment will have as great an 

 influence upon the dragonflies as upon the fish with which it is stocked. In general, a 

 common local species of dragonfly will be far better than one imported from a distance. 

 A visit to neighboring ponds and quiet streams and a careful comparison of their con- 

 ditions and surroundings with those of the proposed fishpond will be the proper 

 method of choosing the species. Find a place as close to the fishpond and as similar 

 to it as possible, and use this as the source from whence to obtain the stock material. 



In 1889 Dr. P. R. Uhler, at that time one of the best authorities upon the dragon- 

 flies, wrote the following to Dr. Robert H. Lamborn (1890, p. 12) in reference to the 

 breeding of dragonflies for the purpose of killing off mosquitos : 



As I have raised all the common forms of our Atlantic coastal-plain region, I know that the dragonfly 

 larvae can be reared in vast numbers. Of course, you know that each locality supports its own species. 



