HOW TO KNOW THE IMMATURE INSECTS 



2b. Antennae present 3 



3a. Antennae consisting of 10 or more segments; cerci usually multi- 

 articulate, long and filiform, or specialized into forceplike structures; 

 abdomen usually 11-segmented, without a furcula or collophore; 

 mesothorax never overlapping and concealing the prothorax. 

 Fig. 49 Order THYSANURA page 55 



They are known as 

 bristletails, silverfish and 

 slickers. About 400 spe- 

 cies have been described. 

 They are found in the 

 soil, in rotting wood, un- 

 der stones, or in leaf-de- 

 posits of forest floors, 

 and also live in the nests 

 of ants and termites. 



Fig. 49. a, Compodeo frogilis Meinert; b, L«- 

 pismo sp.; c, Jopyx minemus. 



3b. Antennae consisting of not more than 8 segments; cerci never pre- 

 sent nor specialized into forcep-like structures; abdomen 6-segment- 

 ed, if segments are visible; generally possesses a furcula and a 

 collophore may be present; mesothorax may overlap and conceal 

 the small prothorax. Fig. 50 Order COLLEMBOLA page 58 



Springtails are small insects rare- 

 ly exceeding 5 mm. in length, and 

 occur in almost all situations. They 

 are found in the soil, in decaying 

 vegetable matter, among herbage, 

 under bark of trees, etc. A few spe- 

 cies live in the nests of ants and ter- 

 mites, other occur on the surface of 

 fresh water and several are littoral 

 or marine. In habits they are sapro- 

 phagous or phytophagous. About 

 1,500 species have been described. 



Fig. 50. Entomobryo comporafa. 



30 



