90 



GEOLOGY OF LA SALLE COUNTY. 



in a knot composed of three or more leaflike pieces. 

 Here we find the May beetle or June buo-, Lachnos- 

 terna quercina, also Cetonia, frequently seen here, and 

 Elaterid^ or spring- beetles, or snapping- bug- — Klater 

 oculatus is marked with two velvety, dark, eye-like 

 spots. Our most common one is horn-brown, three- 

 fourths of an inch long-, and very plenty. Another 

 species is lig-ht horn-brown, has a red head, and is one 

 and one-half to two inches long-. We have seen but 

 few of these. The larva live in rotten wood. The 

 Curculionidse or curculio is well known from his work, 

 if seldom seen. He is very small and very sly. They 

 have a long- snout, long for their size. The Pea Wee- 

 vils belong- here, as do the other wxevils. The Clytus, 

 C. flexuosus, banded with yellow and black, the lo- 

 cust borer is another destructive beetle. 



The chrysmelidse are usually small, long-er than 

 wide, and variously striped. Among- them is the 

 squash bug-. 



The coccinellida^ or lady bug's are round or oval, 

 with convex backs, and are beautifully spotted with 

 ])rig-ht colors. They eat plant lice, and are useful. 

 We have several species, most common, a red one with 

 thirteen B. spots on the back. 



The hemiptera have the mouth in form of a beak, 

 which is folded back under the thorax when not 

 in use. The most important members of this subordes 

 , are the Harvest flies, cicadas or locusts — the seventeen 

 year — not a locust, nor even second cousin to a locust, 

 the Treehopper — cecropidae — of which we have several 

 species; the Plant lice or Aphidse; the boat flies or 

 Notonectidae, aquatic insects which swim on their backs 

 and leaving- the water at nig-ht fly about. The Hvdro- 

 metridae walk on the water. The corcidai or squash 

 bug-, which attack the squash, and Cimicedae or Bed- 



