CHAPTER XV 



Order Rhynchota (Hemiptera) : Bugs 



(Gr. pvyxo? = a snout or beak). 



The mouth-parts in the members of this large order, which 

 includes true stinking bugs, cicadas, aphids, and scale-insects, 

 form a very characteristic beak : two pairs of wings are 

 typically present (though, as in most Orders, wingless species 

 exist) and they may both be membranous, or the front pair 

 may have the basal half thickened and hardened to form 

 a wing-sheath. The metamorphosis is usually " incomplete," 

 but in the case of the males of the scale-insects, is " complete." 



The Rhynchota live by sucking juices; the majority of 

 them live upon the sap of plants, and are responsible for 

 an enormous amount of damage to crops of all kinds, but 

 some prefer the juices of animals, and among these are 

 certain species that suck the blood of man. It is chiefly 

 these last that give the Order an interest for the medical 

 officer ; but he should also take heed of certain useful bugs 

 that destroy other insects, and particularly of those pre- 

 daceous aquatic species that may be reckoned as possible 

 enemies of mosquitoes and their larvse ; nor must certain 

 bugs that furnish useful products be forgotten. 



The mouth-parts are quite characteristic. The labium, 

 or " beak " (Fig. 85) is a segmented proboscis, usually of 

 considerable length, and in repose is bent under the head : 

 it is devoid of palps, and it is so deeply channelled along 

 its whole length as almost to form a tube. In this tube 

 the other mouth-parts lie, so that the labium is, like that 

 of Diptera, a protective sheath, though very commonly, as 

 in certain Diptera, it is also used as a dagger. The mandibles 



and maxillce — which latter have no palps, and are barbed 



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