30 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 39 



Paradichlorobenzene, called PDB, is a good f umigant to use 

 on pests in the collection. It should be used in a nearly airtight 

 chamber, such as a tight trunk, bin, or case, at the rate of 1 pound 

 of PDB to 25 cubic feet of space. The boxes of specimens, with 

 lids open or removed, should be placed in the container, the f umi- 

 gant scattered or spread on a piece of cloth or paper above them, 

 and the chamber sealed for about a week. 



IDENTIFYING THE SPECIMENS 



The complete classification of insects is quite complicated. 

 The entire insect group is first divided into orders, such as the 

 Coleoptera, or beetles, the Diptera, or flies, and the Siphonaptera, 

 or fleas. Each of these orders may contain from several dozen 

 to 25,000 different kinds of insects in North America alone. 

 These orders are divided into families, which in turn may con- 

 tain from one to many thousands of species. The family names 

 always end in idae, as in Pentatomidae, the name for the stink 

 bugs. These families are divided into genera (the plural for 

 genus), and the various species or kinds are placed in the genera. 

 Thus the house fly bears the name Musca domestica Linnaeus; 

 this means that the species name is domestica, that this name 

 domestica was first applied to the species by a man named Lin- 

 naeus and that the species domestica is placed in the genus Musca. 

 Further, the genus Musca belongs to the family Muscidae which, 

 in turn, belongs to the order Diptera. 



As an aid to the preliminary identification of his specimens 

 by the beginner and also as an aid in arranging his collection, 

 a short, descriptive synopsis is given below. In this are noted 

 the most distinctive features of the common insects occurring in 

 Illinois. There are rare and obscure forms seldom met by the 

 collector that require a most technical key for their identifica- 

 tion, but for these the collector will need to consult some of the 

 more nearly complete books listed on page 58. The collector will 

 find, however, that this synopsis will afford a beginning for his 

 classification of the common forms. 



Various characters are used to identify an insect to family, 

 genus, and species. It is always necessary to see the structure of 

 antennae, wings (if present), legs, and mouthparts. Frequently, 

 minute details of these must be examined. Hair or scales cover- 

 ing the body or wings, and the texture of these parts, are impor- 

 tant. Hence, specimens should be kept in good condition. 



