12. MISC. PUBLICATION 318, U. 8. DEPT. OF AGRICULTURE 
The order Homoptera subdivided into some of its families, genera, ana species 
Order | Family | Genus Species 
| 
| 
| - | (gossypii. 
ALTE |) maidi-radicis . 
AS ee ee 1) pomi. 
; Tumicis. 
Aphidae=.20 Cae ARULOCDRIS HR Sa Rae ea TOSEUS. 
[i RESReICORUT Cease sae 7 eee oe + brassicae. 
ti riOSOMG c= 2a 2 Sra lanigerum. 
eenete | MEUS Spates eed Sot pen ers. cerast. 
1eadidae=- ie =e eee (Magicicada 22 septendecim. 
Homoptera - -_-------------- Cicadellidae emma: BRM aes maligna. 
i see ETULNT ONCUTE = = ee | comes. 
Membracidae__--_-_______ Ceresd Ss a et bubalus. 
WAspidiottis: 23s perniciosus. 
: |} CRIONGSTIS== =o aes Sone ae furfura. 
Coceidae____-__-_________- | pkemdosaphes= == ee uime. 
| Pulnniria- = ae | 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 i 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 
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 1 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. 
