THE RELATIONSHIPS OF INSECTS 



61 



divisions of the branches are more or less uncertain. The species in 

 general, group themselves quite easily into different genera and these 

 into families; but while these last can in most cases be definitely placed 

 in their orders, their correct relation to each other is often debatable. 

 The relation of the orders to each other is far from settled, and while 

 some are evidently more closely allied than others, within certain limits 

 one order could follow another in almost any sequence without any serious 

 loss to the expression of relationships. Where orders appear to be closely 

 allied to each other, this will be indicated in connection with their 

 consideration. 



With the relations between the orders and also the families within 

 the orders, still uncertain in many cases, a tree showing these must of 

 necessity express only the views of the individual who drew it. Such a 

 tree carried to the species would be entirely too large for these pages 

 (there are about 80 families of beetles, and many of the other orders have 

 large numbers also), but one carried to the orders is given here (Fig. 34) 

 to illustrate the general idea of a tree-like classification. 



Expressed in tabular form, the classification followed in this book 

 is given below. 



CLASS SUBCLASS ORDER SUBORDER COMMON NAME, OR EXAMPLES 



Apterygota / Thysanura Silver fish, etc. 



\ Collembola Snow fleas, etc. 



Hexapoda 



Pterygota 



Ephemerida . . . 



Odonata 



Plecoptera .... 

 Embiidina. . 



Orthoptera . . . 



Isoptera 



Dermaptera 



f Rhynchophora . 

 Coleoptera< ~ , 



[ Coleoptera vera 



Strepsiptera 



Thysanoptera 



Corrodentia 



Mallophaga 



Anoplura 



Hemiptera 



Homoptera 



Neuroptera 



Trichoptera 



( Heterocera. . . 

 Lepidoptera < , , 



( Rhopalocera . . . 



Mecoptera 



Diptera 



Siphonaptera 



Hymenoptera 



. May-flies 



. Dragon-flies 



. Stone flies 



. (No common name nor 

 examples) 



.Roaches, grasshoppers, 

 crickets, etc. 



. Termites or White ants 



. Earwigs 



. Snout beetles 



. True beetles 



. Stylopids 



. Tlirips 



. Book lice; Psocids 



. Bird lice (biting) 



. Sucking lice 



. True Bugs 



.Scales, plant lice, leaf hop- 

 pers, etc. 



.Corydalis, aphis lions, ant 

 lions, etc. 



. Caddis flies 



. Moths 



. Butterflies 



. Scorpion flies 



.Flies 



.Fleas 



.Saw flies, ichneumon flies, 

 ants, wasns. hees. etr. 



