260 



STATE BOARD OF AGRICULTURE. 



Sun-fish, sticklebacks and mud-minnows* quickly eat the larvie and 

 pupae when in aquaria. One small sun-fish, not over an inch and a 

 quarter long, was fed fourteen good sized larvss at a meal and next day 

 he ate twenty more. While the sticklebacks and mud-minnows did 

 not eat so greedily, they disposed of many mosquitoes. 



The mud-minnow, a small inconspicuous fish, was found in many 

 swales and pools, and wherever found the wigglers were fewer in num- 

 ber, however, they never seemed to be present in suflScient force to entirely 

 eradicate the pests unless introduced artificially. 



As has been stated, the season in Michigan was extremely wet. Rain 

 fell at short intervals so that in many places pools remained all summer 

 where ordinarily they dried up in June. Then too the grass Vv^as almost 



Fig. .5 ^Brook sticklebacks, male and female, slighu.v eiikuKed, oriKinal 



constantly wet, a condition very favorable to mosquito life, and while 

 many millions have been killed in the area treated, the insects have 

 drifted in from the outside. We all know that mosquitoes flourish 

 near water. They must have w^ater and ordinarily they are not sup- 

 posed to drift far from water. It is probable that the wet grass this 

 season has enabled them to drift much farther than ordinarily. 

 Mosquitoes appeared during the middle of May and continued to be in 

 evidence all through the warm w^eather. We can imagine how numerous 

 they would have been if the many millions which were killed had been 

 left to live. Another factor which worked against us was the direction 

 of the prevailing winds. Ordinarily, the wand is from the southwest. 

 Much of the time during the past summer, the wind has come from 



*The sun-flsh belns immature have not been determined. The mud minnow i.s ftnbra limi as kindly 

 determined for me by Prof. Raymond Osbnvn. The stickleback is the one known as the brook 

 stickleback, Eacalia inconstant. 



