The Farm Fishpoxd 



2029 



their chance occurrence. A few insect forms, such as caddis flies, may' 

 flies, damsel flies, midges, and mosquitoes, will 

 undoubtedly come to the pond each year for 

 egg laying, and nearly all of their progeny will 

 probably be exterminated during the same 

 year. There is good reason for believing, 

 however, that the supply of .aquatic insects 

 can be materiall}- increased by building a few 

 small breeding ponds along the margin of the 

 main pond and excluding all fishes therefrom 

 (Fig. 187). Certain insects will naturally 

 deposit their eggs in both breeding and main 

 ponds. There are no very destructive insect 

 enemies in the former; hence there are sure 

 to emerge a goodly number of adults, which 



in turn will con- 



FiG. 188. — Caddis fly larva in 

 a case 



tinue year after year to repopulate the small 

 ponds as well as the main pond. 



Crustacea and Mollusca. — There are a few 

 forms of Crustacea and Mollusca that may 

 be successfully introduced and that will 

 naturally increase in numbers provided there is 



A.lt^ 



Fjg, 189. — Caddis fly larva in 

 a case 



Fig. 190. — Adult caddis fly 



