12 MISC. PUBLICATION 318, U. S. DEPT. OF AGRICULTURE 



The order Homoptera subdivided into some of its families, genera, and species 



Order 



Family 



Genus 



Species 





(Aphiidae 



(Aphis. . 



(gossypii. 



1 maidi-radicis . 







\pomi. 

 [rumicis. 





Cicadidae 



Cicadellidae 



Membracidae 



.Coccidae __ 









Eriosoma. __ ___ 















septendecim. 





(Empoasca 















Ceresa... 







(Aspidiotus ... _ 







1 Chionaspis 



furfur a. 





| Lepidosaphes _ 













(Pulvinaria.. . . 



vitis. 









Thus it can be seen that the cotton or melon aphid (Aphis gossypii) belongs to the family Aphiidae 

 and the order Homoptera. 



FURTHER AIDS TO IDENTIFICATION 



Anyone who is sufficiently interested in insects to want to make 

 a collection, will want to know the names of those collected. Because 

 there are so many different kinds, it is almost impossible to prepare 

 a simple key for identification that the average person can use. 



The best that can be hoped for in this publication is to acquaint 

 club members with the larger groups of insects such as the orders. 

 In some cases it is well to know the families, and, where the insect 

 is of major importance, it is very helpful to be able to identify the 

 species. 





INCHES 







|I|H|II|M 

 1 1 



MM II II 

 1 2 



Milium 

 1 3 



i.i 1 u 



Mill 

 4 



liiiiiifiliiiiiiiiiliiiiiiiiiliiiiiiiiiliiiiiiiiiL 



MILLIMETERS 



Figure 24. — Rule for measuring insects. 



Instead of the usual key, a number of pictures have been used to 

 assist in identification. In some cases the picture of a single insect 

 is shown to represent an entire order, and in other instances the pic- 

 tures represent the family also. Remember that there may be a thou- 

 sand or more insects that are very closely related to the insect shown 

 in the picture, and in many cases closely resemble it. Textbooks and 

 bulletins may be used to help further in identification. 



Since a means of measuring is not always available, the rule 

 sketched above should be useful. The upper portion is divided into 

 inches, and the lower portion into millimeters. 



