INSECTA 273 



mantis, "devil's horse" or "darning needle," grasshoppers, katydids and 

 crickets, 



583. Order 3. — The Corrodentia have biting or rudimentary mouth parts, 

 wings alike, and development without or with little metamorphosis. The 

 group includes the highly interesting "white ants" or termites and the 

 less interesting body lice, ectoparasitic on mammals. The latter are 

 degenerate, lacking wings and having rudimentary mouth parts and eyes 

 greatly reduced. The termites are colonial and polymorphic. The sexu- 

 ally perfect males and females are winged but the wings are later cast off. 

 A third form called a worker and sometimes another form called a soldier 

 may also be found. These are individuals in which the reproductive 

 system remains undeveloped. 



584. Orders 6 and 7. — The Odonata, "damsel flies," dragon flies, and 

 Ephemeroidea, "day flies," are found only in the vicinity of fresh-water 

 ponds or streams in which the larval development takes place. 



585. Order 8. — Some of the Neuroptera, "lace wings," also develop in 

 the water as for example Corydalis whose larva is the "hellgrammite." 

 The ant lion ("doodle bug") is the larva of another "lace wing." The 

 Odonata have an incomplete, the Ephemeroidea and Neuroptera a complete 

 metamorphosis. All the remaining Orders except the last, Rhynchota, 

 also undergo complete metamorphosis. 



586. Order 11. — The large order Lepidoptera, butterflies and moths, is 

 perhaps the most readily distinguished of all. Here the maxillae are 

 modified for sucking and form a proboscis. The two pairs of wings are 

 similar and covered with scales. The prothorax is united firmly with the 

 mesothorax. The larva is a caterpillar with distinct head and jaws devel- 

 oped for biting. The head also bears two antennae and two or three pairs 

 of simple eyes. The first three segments behind the head have jointed 

 appendages and there are besides on the segments of the abdomen from 

 two to five pairs of false feet. After a time of voracious feeding and rapid 

 growth the larva attaches itself in some sheltered place or spins a cocoon 

 of silk fibres. It then undergoes a complete change of form, meta- 

 morphosis, becoming a quiescent pupa in which condition it continues 

 for a short time if it is in the summer or through the winter if pupation 

 takes place in the fall. Finally another transformation takes place, the 

 integument of the pupa bursts and the imago emerges in all respects a 

 mature insect. The life period of the imago is usually brief; the female 

 is fertilized, deposits a single brood of eggs and dies. 



587. Order 12. — The Diptera or two wings include the flies, gnats, and 

 mosquitos. They have mouth parts developed for sucking or piercing. 



18 



