INSECTS AND OTHER SMALL ANIMALS 311 



licks the hair where the eggs are fastened, they hatch 

 and are taken into the mouth of the horse. They soon 

 find their way to the stomach, where the larvae often col- 

 lect in large numbers, fastening themselves to the 

 walls of the stomach. They are not usually dan- 

 gerous. They may be prevented by keeping the horse 

 well groomed. 



Ox warbles are a botfly that infest cattle. The eggs 

 are fastened to the hair as with the ordinary botfly 

 and reach the gullet of the animal in the same way. 

 From the esophagus the larva works its way through 

 the tissues till it comes to the hide. Here it makes a 

 small hole for breathing and for escape. It remains 

 here and causes a tumor to form under the skin. These 

 tumors are called warbles. In the early spring the 

 larva comes out, falls to the ground, and, after digging 

 into the soil a few inches, changes to the pupal stage. 

 After about a month it becomes a fly. The larva 

 causes great damage to hides by puncturing them, mil- 

 lions of dollars being lost annually on this account. No 

 satisfactory remedy has been found for the warbles. 



Butterflies and Moths (Lepidoptera, scaly-winged). 

 This order is characterized by having the wings covered 

 with feathery, overlapping scales. The mouth parts 

 are formed into a tubular tongue which, when not in 

 use, is coiled under the head. They pass through a 

 complete metamorphosis. 



Butterflies are distinguished from moths in a number 

 of ways. The most apparent differences are the fol- 

 lowing : (a) The moths are night fliers as a rule, while 

 butterflies fly in the daytime. 



(&) Moths have thicker, stubbier bodies than the 

 butterflies. 



