224 



The Orders of Insects 



The larva; are white, fleshy grubs, usually without legs, with greatly 

 wrinliled skin, and bent bodies (fig. 123). Both they and the 

 beetles are vegetable-feeders ; many species cause great damage by 

 their attacks on the roots, leaves, and wood of cultivated plants. 

 The family is world-wide in its range. 



Scolytidae. — ^The Scolytida or Bark-beetles are small cylindrical 

 beetles which agree with the Curculionidse in the short, rigid palps 

 of the first maxillx, and in the absence of a distinct labrum, but 

 differ markedly in the slight development of the snout. The 

 strongly clubbed feelers are inserted on the sides of the head 



between the eyes 

 and the man- 

 dibles. The 

 pronotum often 

 covers the head ; 

 the legs are stout 

 with the fore- 

 shins toothed on 

 the outer edge 

 (fig. 124). The 

 larva are legless 

 grubs like those 

 of the Cur- 

 culionidx ; they 

 and the beetles 

 usually live in 

 galleries which 

 they eat out in 

 trees between 

 the bark and the 

 wood; a primary 

 tunnel is made 

 by a female who 

 lays eggs there- 

 in, and the grubs 

 when hatched 

 quickly make 

 branch -galleries 

 (see fig. 163). 



Fig. 123. — a. Grain Weevil (Calandra granaria, Linn.). 

 b. larva; c. pupa; d. C. oryzae, Fab., Europe. 

 Magnified 7 times. From Chittenden, Yearbook, 

 U.S. Dept. Agr., 1894. 



Stylopidae. — The Stylopida, the concluding family of the Beetles, 

 are so aberrant in form that by some entomologists they are 

 considered a distinct order — Strepsiptera. They are very small 

 insects whose males have the forewings greatly reduced and 

 twisted, while the hindwings are very broad and fold lengthwise. 

 The feelers are branched, and the jaws much reduced. The females 

 are blind and worm-like ; they spend their whole lives within the 

 bodies of bees and other insects whereon they are parasitic, and in 



