432 SYNOPTIC COLLECTION. 



female, inasmuch as it passes through a normal larval, 

 pupal, and winged adult stage, but it is more specialized 

 by having a quiescent pupal stage and an indirect develop- 

 ment unlike any of the insects in the large group of 

 Insecta including orders 1-9, which we have been describ- 

 ing. The quiescent pupa (fig. 8) is, in fact, here met for 

 the first time, as is also its covering or cocoon (fig. 9), 

 which in this case is made of wax so that it melts readily 

 when heat is applied. 



Associated with this specialization in development there 

 is the loss of mouth parts in the adult male (fig. 10), and 

 the reduction of the second pair of wings to organs that 

 resemble the halteres or balancers of the Diptera, the 

 most specialized order of the class of Insecta. 



Order 10. COLEOPTERA. 







The more generalized members of the Coleoptera have 

 larval characters in common with the Thysanura, while 

 the adults are similar in certain features to the Enplexop- 

 tera, Orthoptera, and Hemiptera. The most specialized 

 Coleoptera, on the other hand, have lost completely the 

 larval Thysanuriform characters and the adults are far 

 removed from their generalized ancestors. 



For the sake of clearness we will consider, first, those 

 beetles whose larvae resemble more or less the Thysanura ; 

 secondly, those which have larvae in the form of soft, 

 cylindrical, and active grubs, possessing three pairs of 

 feet ; thirdly, those whose larvae are elongated, with min- 

 ute feet, suggesting in their general aspect the caterpillars 

 of the more specialized order, the Lepidoptera; and, 

 fourthly, those whose grub-like or caterpillar-like larvae 

 have become specialized by reduction, so that they are 

 soft, cylindrical and inactive, having only vestiges of feet, 

 or in some cases being wholly without these organs. 



This arrangement not only holds good for the order 



