CHARACTERISTICS OF INSECTS 5 



ally means the loss of time and money in attempting unsuitable remedies 

 or neglecting good opportunities. 



Characteristics of Insects 



The place of insects in the animal world is in a group known as 

 Ai'thropoda, a word meaning '' jointed foot." They are related on the 

 one hand to spiders, scorpions, and cen- 

 tipedes, and on the other to crabs, 

 crayfish, and the other crustaceans. 

 With these animals they have various 

 points in common ; for example, a hard- 

 ened body wall or " external skeleton," 

 jointed legs occurring always in pairs, 

 and a body made up of distinct rings or 

 segments. 



Other characteristics are peculiar to 

 insects alone, and serve to define them. 

 These are as follows : a body composed 

 of three distinct regions, head, thorax, 

 and abdomen; one pair of compound 



eyes; one pair of antennae, or "feelers"; three pairs of legs; two 

 pairs of wings ; and a peculiar, complicated type of growth, called 

 metamorphosis, by which the individual goes through three or four 

 unlike stages in its life round. 



Fig. 1. — A mite. An ar- 

 thropod, related to insects. 

 Enlarged and natural .size. 

 Original. 



