INSECTS. 219 



ORDER III. PSEUDOITEUROPTERA. 



These forms, like the Orthoptera, have biting mouth- 

 parts, and have a gradual change from the young to the 

 adult, but they differ from those forms in having both 

 pairs of wings alike, usually very thin and transparent, 

 with very numerous veins, and not capable of being folded 

 like those of the Orthoptera. There are two divisions of 

 these Pseudoneuroptera. In the first the younger stages 

 are passed in the water, in the second on land. 



Examples of the first are seen in the dragon-flies 

 (ODONATA); their larvae live in the water, where they 

 feed upon other insects, etc., and especially on the larvae 

 of mosquitoes. When the adult stage is reached and they 

 take to the air, they are veritable dragons, feeding upon 

 insects, which they catch on the wing. Here, too, belong 

 the May-flies or day-flies with an aquatic life of from one 

 to three years, a life in the air of but a few days, or even a 

 few hours. These May-flies often appear in great numbers 

 in the cities near the Great Lakes. 



The celebrated white ants or termites may represent the 

 forms with a solely terrestrial life-history. These are not 

 "ants" -at all in the true sense of the word, but they 

 resemble them in several points. They form large colonies 

 consisting of several distinct "castes" with different 

 structure. Only the kings and queens are winged, and 

 only these are capable of reproduction. Besides these 

 there are "workers" and '' soldiers." The workers build 

 the nests, gather the food for the whole colony, and bring 

 up the young. The soldiers have enormous heads, and 

 protect the others. The termites are miners, and make 

 their burrows beneath the earth and inside of dead wood. 

 They avoid the light, and where they cannot otherwise 



