IOWA ACADEMY OF SCIENCES. 211 



Adult Fig. 10. (a, dorsal view; b, side view; c, tarsus.) 

 Widest at base of elytra and tapers strongly toward either end; 

 shining black, glabrous; numerous medium sized punctures 

 on the thorax and between the striae of the elytra. Snout 

 about 1-24 inch long, curved, usually extending directly 

 downward, but sometimes drawn backward or slightly pro- 

 jected forward. Thorax narrows perceptibly toward the head. 

 Tarsi strongly pubescent beneath, claws strongly curved, 

 diverging. Elytra emarginate at tip, making the tip of 

 abdomen more distinctly visible from above. 



REMEDIES. 



Collecting and burning the old root-stocks and stems in early 

 autuma will be the most effective treatment that can be sug- 

 gested from present knowledge of the species. 



AN INSECT OCCURRING IN WATER TANKS AND RESERVOIRS. 



{Chii'onomus sp ) 

 Early in July I received some sp :cimens of a slender red 

 larva from Boone, with the f'jllowiug letter: 



Professor Osborn: 



Dear Sir— Enclosed I send a sample of the worm that appeared in our 

 city water about a week ago iu countless numbers. Would like to know 

 what they are and where they would be likely to come from. The water we 

 use comes from a 3,0j0-foot well, but about two weeks ago our pumps failed 

 and we were supplied with water from a forty-five foot vein owned by the 

 C. & N. W. Ry. Co., and pumped to our reser/oir through a hose. 



Yours truly, E. E. Chandler, 



Chairman Water Committee. 



Boone, Iowa. 



The li,rva3 were evidently Chironomus, and in replying to the 

 letter it was so stated and that in themselves they could be 

 considered harmless, though oi course the presence of masses 

 of such ugly looking creatires wou'd be objectionable, and if 

 dying in the water taey might become a source of pollution 

 Also that the larvse must have gained access to the water from 

 the eggs of the adult mosquito- like insect being deposited in 

 the reservoir or the mains by which it was filled. They could 

 not be derived from a deep well. It was suggested that pro- 

 vision be made to exclude the insects from the water to prevent 

 deposition of eggs. 



The larva3 (Pig. 12) (/ and h , which are an inch or a little 

 more in length and of a light red color with green reflections 

 on the sides near the head, construct a tube at the bottom of 



