HOW TO KNOW THE INSECTS 



22b Not as in 22a 23 



23a Small narrow insects, flattened on the sides; sucking 



mouthparts; hind legs for jumping; five tarsal segments. 



(Fleas) Fig. 60. Order XXIV, SIPHONAPTERA 



Fig. 60. The Dog Flea. 

 Curtis. 



Ctenocephalis canis 



Reddish brovm. Infests dog. cat and man. 

 Length 3-5 mm. (from U.S.D.A.) 



Fleas parasitize both the mammals and birds 

 and live by sucking the blood of their host. 

 The larvae are worm-like and live on decaying 

 organic matter. 



23b Not as in 23a 24 



24a Body thickly covered with scales, mouthparts for sucking 

 or absent. (A few female moths) Figs. 61 and 198. 



Order XXI, LEPIDOPTERA p. 89 



Fig. 61. The Spring Cankerv/orm. 

 Paleacrita vernata Peck. 



female 



Gray, covered vjith scales, 

 to April. Length 10-15 mm. 



Appear from February 



Figure 61. 



24b Not as in 24a 25 



25a Very delicate insects with chewing mouthparts and long, 

 jointed thread-like tails and antennae. (Fishmoths, bristle 

 tails, firebrats). Fig. 62. Order I, THYSANURA 



Fig. 62. The Sllverfish. Lepism.a saccharina L, 



Light silvery gray. Soft body, flattened. 

 Runs rapidly. Length about 15 mm. (from 

 U.S.D.A.) 



The members of this order are lovers of 

 starch, so are found in old papers and books, 

 under wall paper and in starched clothes. One 

 species known as the flrebrat is seen in fur- 

 nace rooms and about fire places. It apparent- 

 ly can stp.rd rather high temperatures. 



Figure 62. 



25b Not as in 25a 



26 



47 



