DRAGONFLIES AND DAMSELFUES IN PONDFISH CULTURE. 



187 



each of them contains enough aquatic plants to make it very attractive to both dragon- 

 flies and damselflies. The distribution of fish and vegetation in and around these 

 ponds is shown in the two tables which follow. 



It may be noted that a heavy fringe of common crex grass, Car ex striata, has been 

 planted at the water's edge around each of the ponds in order to prevent wave washing 

 (PI. LXVII, fig. i). Ponds I, 2, 3, and 7 are partially covered, at the proper season 

 of the year, with a thick scum composed of the pollen of Philotria blossoms; ponds 

 4 and 8 show this scum in much smaller quantity, while it has not as yet appeared 

 in the other ponds. 



Along the north embankment of ponds i, 2, 3 and 4 runs a cinder road (PI. LXVII, 

 fig. 2), to the north of w^hich, away from the ponds, the land rises rapidly and was 

 covered during the two summers of the present investigation with a heavy growth of 

 grass, in which the dragonflies were accustomed to roost at night. This upland grass 

 field up to the time of mowing was literally filled with odonate imagos, Libellula liictuosa 

 being most numerous. Females could be found there at any time of day, and toward 

 night or early in the morning, especially after a heavy dew, both sexes were present in 

 large numbers. The algae, pondweed, and rushes around these ponds furnish exactly 

 the conditions favorable for odonate propagation, and, taken in connection with this 

 ideal roosting place, with the constant supply of fresh water, and with the abundance 

 of food, they present an exceptionally fine breeding ground for dragonflies and damsel- 

 flies. This is shown not only by the comparatively large number of species found 

 around these ponds but also by the extraordinary abundance of some of them. 



To the south of the ponds along the railroad track is a ditch which always contains 

 more or less water and which proves a favorite haunt for Plathemis lydia, Anax junius, 

 Libellula pulchella, and Pachydiplax longipennis. There is a fringe of willows along 

 the river bank opposite the ponds, and the slope of the terrace to the north of the 

 dwelling houses beyond the highway is also wooded, but there are no trees or bushes 

 anywhere in the vicinity of the ponds themselves. 



The plankton of the ponds is very rich in entomostraca and other forms of life, 

 and the water plants are covered with snails and insect larvae of all kinds, furnishing a 

 good food supply. 



Fish Distribution in Ponds of Series D, Fairport, Iowa, 1916. 



.Species. 



Pond numbers. 





2 



3 



4 



5 



6 





8 



9 





X 

 X 



X 



X 







X' 









Micropterus saimoides: Largemouth black bass, yearlings 













Micropterus dolomieu: Smallmouth black bass, adults 











X 

 X 











; xxxx; 













X 





Pomoxissparoides: Black crappie, yearlings 















Lepomis incisor: Bluegill, adults 



X 

















Lepomis incisor: Bluegill, 2-year olds 

















Ictiobuscyprinella: Red-mouth buffalofish, adults 







X 

 X 













Ictiobusbubalus: Smalbnouth buffalofish, adults 



















Ictiobusbubalus: Smallmouth buffalofish, yearhngs 









X 











Ictiobus bubalus: Smallmouth buffalofish, fry 













X 



















X 







Lepomis euryorus: Wide-eared sunfish, adults 















X 

 X 





Chaenobryttus gulosus: Warmouth bass, adults 



















Ictalurus punctatus: Channel catfish, adults 

















X 

 X 



Ictalurus punctatus: Channel catfish, fry 





































