﻿I 



GENERAL INTRODUCTION. 



The Hemiptera. or R'hynchota. are readily distinguished from 

 ixll other orders of insects by the structure of the mouth, which 

 consists of a grooved sheath, usually in the form of an elongate 

 proboscis, in which lie enclosed four setae; in some respects 

 the Order is perhaps the most isolated of all true insects, and 

 is certainly in many more, one of the most interesting. 



As Dr. Sharp has very truly said, "there is probably no order 

 of in.sects that is so directly connected wit'h the welfare of the 

 human race as the Hemiptera; indeed, if anything were to ex- 

 terminate the enemies of Hemiptera, we ourselves should prob- 

 ably be starved in the course of a few months." 



It is not alone the exhaustion consequent upon the rapid 

 draining of the plant's juices by the Hemipteron's almost micro- 

 scopic mouth-setae, that is so deleterious; it is the addition of 

 the 'horde of fungus spores which often subsecpiently attack the 

 wounded sur'face, and quickly multiplying, penetrate into the 

 tissues of the plant, causing decay and death. 



Here should be noted a common error among entomolo- 

 gists who are not specialists in Hem'ptera. The probocis-like 

 rostrum (labium) probably iici'cr penetrates the tissues, neither 

 vegetable nor animal, unless these be already lacerated by the 

 setae; it is simply a sheath to protect the delicate piercing 

 organs, and more or less of a fulcrum to steady their operations. 



Such injurious Hemiptera as the Chinchbug (Blissns leitcop- 

 icrus) the Bed-bug {Clinocoris Icctulariiis) the Cotton Stainer 

 (Dysdcrcus sutuycUns), the Coffee-blight {HelopcUis antoiiii), the 

 I'lantlice (Aphidac), the White tlies (Alcyrodidac) and the Mealy 

 bugs and Scales (Coccidac), are household names and to these 

 must be added the Sugar-cane Leaf-hopper {Pcrkiiisiclla suc- 

 cliaricido). 



Six hundred million dollars \yould be an exceedingly con- 

 servative estimate of the values of rhe damage occasioned all 

 over the world each year by the depredations of the Hemiptera, 

 taking everything into consideration. 



And one cause of this devastation is the extraordinary rapid- 

 ity of increase, which were it not for restraining parasites and 

 predators, would in a year (jr two leave not a single green leaf 

 on the earth. ( ).sborn estimates that in North .America, one- 



