176 A BOOK OF INSECTS 



and black, and drawn up in front of the centre of the 

 corolla, the simulation of a papilionaceous flower is com- 

 plete. The object of the bright colouring of the under 

 surface of the prothoracic expansion is evident, its purpose 

 being to act as a decoy to insects, which, mistaking it for 

 a corolla, fly directly into the expectant, serrated, sabre-like 

 raptorial arms of the simulator." 



The nymph of at least one kind of bug {Reduvius 

 per$o?iatus) has the very curious habit of enveloping itself 

 in a coating of dust and small particles of any refuse 

 among which it may chance to wander. This habit is 

 doubtless protective, but it also serves an aggressive 

 purpose. The Reduvius is a cosmopolitan species which 

 frequents the cellars and basements of dirty houses, where 

 it does good service by preying upon other insects — includ- 

 ing cockroaches and the objectionable bed-bug. It pierces 

 its victims with its sharp " beak," and extracts their juices 

 exactly as its vegetarian relatives suck the sap of plants. 



Many other terrestrial Hemiptera, and most of the 

 aquatic species, are carnivorous. Among the latter are 

 the giant water-bugs of the family Belostomidce. These 

 are abundantly represented in the warm regions of both 

 hemispheres, and some of the species attain a length of 

 nearly five inches. Their grasping fore-legs enable them 

 to hold their prey with great firmness, while their strength 

 is such that they can grapple successfully with such crea- 

 tures as frogs and small fishes. When full-grown, these 

 bugs have large and powerful wings, so that they are able 

 to leave the water and fly to great distances. Certain 

 North American species have been found in the midst of 

 cities far from ponds, and are known as "electric light 

 bugs " because they are attracted by bright lights on the 

 top of high buildings. 



In our own country, the best-known carnivorous water 



