ECONOMIC PHASES OF THE GRASSHOPPER 29 
The grasshopper belongs to the order known as Orthoptera, 1 
(or-thop'ter-a : Greek, orthos, straight: pteron, wing). In the 
Orthoptera we find six common families: grasshoppers, 
crickets, katydids, cockroaches, walking sticks, and praying 
mantids. 
15. Economic Insects. — By economic insects, we mean 
those insects which, by their activities, are either helpful or 
harmful to man. By saying that an insect has no economic 
importance we mean that it does not harm us by eating 
things useful to us and that it does not help us in any way. 
The struggle to live is a problem for all animals, for man 
as well as for the grasshopper. All insects must eat, and 
some eat the same things we wish to eat. Such insects we 
call harmful. Others aid the growth of plants by carrying 
the pollen dust from one flower to another; others make 
honey. Such insects are useful. Certain other insects, 
like the fly, carry the germs of disease. These insects are 
particularly harmful, for they cause sickness and death. 
Certain beetles eat dead flesh or bury dead animals 
by tunneling under them. Such insects are helpful. We 
should study insects in order to find out which are our 
friends and which our enemies. It would not do to kill 
all kinds of insects, for in many cases we should harm our¬ 
selves. 
16. Economic Phases of the Grasshopper. — The grass¬ 
hopper eats the leaves of plants, and if there are many grass- 
1 grasshoppers, katydids, crickets 
butterflies and moths 
beetles 
bugs 
bees, wasps, ichneumones, gall flies 
flies and mosquitoes 
dragon flies 
May flies 
stone flies 
(straight wings) 
(scaly wings) 
(shield wings) 
(half wings) 
(membrane wings) 
(two wings) 
(teeth) 
(short lived) 
(net wings) 
(wingless) 
often called siphon-mouthed 
Orthoptera 
Lepidoptera 
Coleoptera 
Hemiptera 
Hymenoptera 
Diptera 
Odonata 
Ephemeridse 
Plecoptera 
Aptera 
Siphonaptera 
