ROLL CALL 101 



Order 12— Thysanoptera — Thrips (Thnps, Franklinella, Crypiolhnps). 



Characteristics: Piercing mouth parts; either wingless or with two pairn 

 of long, narrow membranous wings, practically veinless; large, free pro- 

 thorax; feet clawless but possessing small protrusible membranous sacs 

 for clinging; manj^ parthenogenotic ; gradual metamorphosis. 



Order 13 — Anoplura — Sucking lice {Pediculus, I'hthirins). 



Characteristics: Wingless ectoparasitic lice with piercing and sucking 

 mouth parts; eyes poorly developed or absent; parasitic on bodies of 

 mammals ; gradual metamorphosis. At least two species, the head louse 

 and crab louse, occur on man. 



Order 14 — Hemiptera — True bugs {Artocorixa, Lethocercus). 



Characteristics : Either wingless, or with two })airs of wings ; in such cases 

 fore wings are thickened at base ; mouth parts adapted for piercing and 

 sucking; gradual or simple metamorphosis. Members of this group con- 

 tain many interesting and sometimes economically important forms. The 

 water-boatmen (Corixidae) have long, flat, fringed metathoracic legs which 

 are adapted for swimming. These peculiar forms carry a film of air about 

 body when under w^ater. The leaf bugs (Xeridae) are frequently numer- 

 ous and injurious to plants. Bedbugs (Cimicidae) have been accused of 

 transmitting various diseases. The cabbage bug does damage to garden 

 vegetables. 



Order 15 — Homoptera — Cicadas, aphids, leaf-hoppers, and scales {Euscclis, 

 Empoasca, Rhopalosiphum) . 

 Characteristics : Mouth parts adapted for piercing and sucking ; two pairs 

 of wings of uniform thickness held over back like sides of a roof. The cica- 

 das (Cicadidae) are better known as the "seventeen-year locust." Plant- 

 lice (Aphididae) are mostly small green insects that suck juices from 

 plants and have a gradual metamorphosis. 



Order 16 — Dermaptera — Earwigs (Anisolabis, Labia). 



Characteristics : Either wingless, or possessing one or two pairs of wings ; 

 in such cases fore wings are small and leathery, meeting in straight line 

 along back; chewing mouth parts ; gradual metamorphosis. Earwigs are 

 nocturnal and feed principally upon vegetation. 



Order 17 — Coleoptera — Beetles and weevils {Hydrous, Dytiscits, Photinus, 

 Anthonomus). 

 Characteristics : Either wingless or with two pairs of wings, fore wings 

 being hard and sheathlike {elytra); hind wings membranous and are 

 folded two ways under elytra; large movable prothorax; chewing mouth 

 parts; complete metamorphosis. Many forms are found in this group. 

 as the tiger beetles, fireflies, click beetles, whirligig, ladybird, and leaf 

 beetles. 



Order 18 — Strepsiptera — Stylopeds {Xenos). 



Characteristics: Mouth parts reduced or wanting; nutrition by absorp- 

 tion; males possessing club-shaped fore wings and large membranous 

 hind wings ; females wingless and legless ; life cycle complex ; para.sitic on 

 bees, wasps, and homopterous bugs. 



