RHYNCHOTA 



191 



engaged in sucking. Both leaf-sucking and blood-sucking 

 Rhynchota employ a proboscis of the same kind, but in the 

 latter the styles are usually stiffer 

 and stronger, while the spine- 

 like labrum generally becomes 



available for stabbing. There \ ^Mk. 



are usually three joints in the 

 tarsus, but only one in Coccidse. 

 The female often possesses an 

 ovipositor, which may be used 

 to make incisions as well as to lay 



Life-history. — The young differ 

 little from the adult as a rule. The 

 proboscis is present from the first, 

 and the mode of feeding does not 

 undergo change. As in Orthoptera, 

 the wings are developed outside 

 the body, and increase at suc- 

 cessive moults. In male coccids 

 there is a resting-stage with histo- 

 lysis, and a near approach to com- 

 plete metamorphosis. Partheno- 

 genesis occurs in aphids and coccids, 

 and in aphids there is polymorphism 

 among the individuals of the same 

 generation which, in certain cases, 

 brings about an unparalleled com- 

 plexity in the life-history. 



Mode of life, etc.^Most Rhyn- 

 chota are vegetable feeders, but a 

 good many are bloodsuckers. Many 

 make galls upon plants. Some 

 are aquatic, and even marine. 



Fig. 99.— Mouth-parts of bug. 

 Copied from Landois. 



The Sub-orders of Rhynchota (Heaiiptera) 



Sub-order I. — Heteroptera (i.e. with dissimilar wings). 

 The fore pair are tough and protective, except at the tip, 

 which is usually membranous ; when at rest they are folded 

 flat upon the back. 



