58 



MISC. PUBLICATION 318, U. S. DEPT. OF AGRICULTURE 



PLECOPTERA.— Plecos (plaited), pteron (a wing). 

 Four netted, veined wings, front pair narrow, hind pair 

 very broad and folding like a fan, folded flat on abdo- 

 men when at rest. Mouth parts for chewing. Life 

 changes incomplete. Stoneflies. 



MECOPTERA.— Mecos (length), pteron (a wing). Four 

 long, rather narrow wings, with numerous cross veins. 

 Mouth parts elongated into a snout three times as long as 

 width across the eyes; chewing portion of mouth parts at 

 end of snout. Life changes complete. Scorpion flies. 



Figure 131. — Scor- 

 pion fly. 



Figure 133. — Twisted- 

 wing parasite. 



COLLEMBOLA.— Colla (glue), embolon (a bolt or bar). 

 Tiny, primitive, wingless insects. Mouth parts for chewing, 

 sunken into head. Never more than six abdominal segments. 

 First segment with a forked adhesive organ or ventral tube. 

 Fourth segment with a forked spring, which the insect uses 

 to flip itself along. No metamorphosis, that is, no changes in 

 form during the life cycle. Springtails. 



STREPSIPTERA.— Strepsis (a turning or twisting), 

 pteron (a wing). Four wings, front pair reduced to 

 mere clubs, hind pair triangular. Eyes stalked, degen- 

 erate. Mouth parts for chewing. Mouth parts mere 

 vestiges. Wormlike insects, living throughout life in the 

 interior of other insects. (Females without wings, eyes, 

 or antennae.) Twisted-wing parasites. 



CALENDAR OF ACTIVITIES, THIRD YEAR 



Meetings 



Telling others about 

 insects 





Organization. 

 Outline work. 



[Playlets. Surveys. 

 [Demonstrations. 

 [Exhibits. 

 [Fall surveys. 

 } Playlets. 



Second, March 



Third, April _ . . 



Fourth, May _. 







Seventh, August 







Eleventh, December 





PLAYLETS 2 



Playlets can be effective teaching devices. There is no question that 

 through playlets many people can be "shown the light" to better insect 

 control when dramatic situations dealing with the solution of some 



2 Playlets may be given at the April, May, December 

 calendar of activities for third-year Avork. 



and January meetings. See 



