GENERAL I XTRODLXTION. 



The Hemiptera. or R'h)iichota, are readilv disting-uished from 

 ;JI other orders of insects l)v the structure of the mouth, which 

 consists of a gTooved slieatli. usually in the form of an elongate 

 pro'boscis. 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 insects that is so directly connected with the welfare of the 

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

 terminate the enemies of Hemiptera, we ourselves should prob- 

 a1)l\- be star\-ed 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 mout'h-setae, that is so deleterious; it is the addition of 

 the 'horde of fungus spores which often subsecjuently attack the 

 wounded surface, and quickly multiplying, penetrate into the 

 tissues of the plant, causing decay and death. 



Here should be noted a comliion error among entomolo- 

 gists who are not specialists in Hemiptera. The probocis-like 

 rostrum {labium) probablv iic-L'cr penetrates the tissues, neither 

 vegetable nor animal, uidess these be alreadv lacerated bv the 

 setae; it is simplv 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 {Blissits leiicop- 

 trnis) the Bed-bug {Cliiiocoris hrfulayiiis) the Cotton Stainer 

 (Dysdcrcus siifiiirlliis), the Coffee-blight (Hclopclfis antoiiii), the 

 I'lantlice i^^phiciac). the White f\\es (Alcyrodidae) and the Mealy 

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

 nmst 'be added tke Sugar-cane Leaf-hopper {Pcrkiiisic/la sac- 

 charicida). 



Six hundred million dollars would be an exceedingly con- 

 servative estimate of the values of the damage occasioned all 

 (jver the world each year by the depredatiotis 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, w'ould in a year or two leave not a single green leaf 

 on the earth. Osborn estimates that in Xorth America, one- 



