Order RHYNCHOTA. 



Suborder HETEROPTERA. 



Family PENTATOMIDtE. 



The family Pentatomidce is the largest in the Heteropterous 

 Rhynchota, and some of its subfamilies are represented in all parts 

 of the world where the Ehynchota exist. They are easily recog- 

 nized insects, having a somewhat common facies, and comprise 

 some of the best known and most handsome species in the whole 

 Heteroptera. It is probably owing to their conspicuous colora- 

 tion that we know so much of the family as we do, collectors 

 always sending specimens home with other insects. Of their habits 

 much is still to be learned, and a knowledge of their life-histories 

 during their incomplete metamorphoses will probably be of the 

 greatest value to farmers and horticulturists. Many species 

 possess a very puugeat odour; but the purposes of this attribute 

 are little understood, and await the explanation only to be ob- 

 tained by systematic and detailed observation. Another feature, 

 still unexplained, is the resplendent coloration of some species 

 compared with the more modest and dull appearance of many of 

 their congeners. A theory of " warning colours " is usually pro- 

 posed to account for such peculiarities, but this theory, or rather 

 suggestion, still requires confirmation. 



The structural characters of the Pentatomidae have been well 

 enumerated by Stal, and there is little to add to his diagnosis. 



Head frequently clypeated. Antennae three-, four-, or five- 

 jointed, inserted on the lower side of the head below the lateral 

 margins. Rostrum of four joints, inserted usually near the labrum 

 towards the apex of the head, rarely towards the base of the same. 

 Scute] lum variable in size, very large or mediocre, reaching at least 

 to the base of the membrane. 



The number of subfamilies to be recognized is largely a matter 

 of opinion. The latest standard publication is the Catalogue of 

 Lethierry and Severin (not yet completed), in which fifteen 

 subfamilies are adopted, of which eleven are found in the fauna of 



TOL. I. B 



