42 INSECTS 



out of the cells from which the liquid matter has been 

 abstracted. More rarely a positive poisoning of the 

 tissue occurs, due apparently to the injection into it 

 of the salivary secretion of the insect, and this may 

 result in the death of all that portion of the plant be- 

 yond the puncture. That sort of injury is often pro- 



PIG. 12. Mouth parts of a plant louse a, the jointed beak; b, the 

 lancets; c, the feeler; d, the foot. 



duced on succulent plants like the Cucurbs, including 

 cucumbers, melons and the like, or Solanacea, includ- 

 ing potatoes, tomatoes, egg-plants, etc., the offenders 

 being mostly plant bugs of the families Capsidce, Lyg- 

 (zidaz or Coreidcs. 



Plant lice are universally distributed and there is 

 scarcely a plant not in some way subject to their attacks. 



