Springtails (Collembola) 
of the 
St. Louis Area 
ELMER D, BUEKER 
Senior High School, University City, Mo. 
The insects may be grouped into the primitive wingless 
group, subclass Apterygota, and the winged, subclass Pterygota. 
The springtails, Collembola, and the bristle-tails, Thysanura, are 
the two orders of the subclass, Apterygota. The wingless condi- 
tion of this subclass is a primitive one and has not been acquired 
as a result of parasitic habit as in lice and fleas. Chewing mouth 
Parts, wingless condition, and young which resemble adults 
in form indicate a likely resemblance to the earliest forms of 
insect life. Florissant Colorado deposits have yielded a species, 
Planocephalus aselloides Scudder, 1890, which is related to pres- 
ent day Collembola and yet shows some affinities to Thysanura. 
Species of Collembola developed a springing organ, the furcula, 
Which is attached to the ventral side of the fourth abdominal 
Segment. This appendage is normally folded beneath the ab- 
omen. When the insect suddenly extends this organ it springs 
about; hence, the name springtails. 
