126 NEW YORK STATE MUSEUM 



one plant after another assumed an unhealthy appearance and 

 died. The attack was characterized in particular by a discolora- 

 tion of the leaves accompanied by a dark spotting, due to excre- 

 ment, and the cast skins of the young were also abundant. Th 

 general appearance of a badly infested leaf is shown on plate 3 



Life history. The breeding of this insect was placed in Mr C. M. 

 Walker's charge, but owing to pressure of other work he was 

 unable to give it all the attention desirable. He learned, however, 

 that the eggs were laid on the underside of the leaf, being thrust 

 under the epidermis along the larger leaves and veins, leaving 

 only the small, yellowish, conical cap in sight. The eggs soon 

 hatch and the young develop rapidly, since between June 11 and 

 23 a life cycle was nearly completed. The feeding of the insect 

 causes white, irregular blotches to appear, and if the attack is at 

 all severe, withering of the leaves. The various molts follow each 

 other quickly and the cast skins soon become so abundant as to 

 give the impression of a bad infestation, whereas only a few 

 bugs may be present. The insects are very active and pass readily 

 from one plant to another, though none of the adults were 

 observed to fly. 



Description. This species has been the object of considerable 

 study, and the following descriptions and the" original illustrations 

 were made under our direction by Mr C. M. Walker. It is be- 

 lieved that all stages are described below though they were not 

 obtained by close breeding. 



Egg [pl.4, fig.l]. Length about .5 mm, width .25 mm. Ovate, 

 somewhat fusiform ; visible tip truncate, collared, within which is 

 a small, yellowish, ridged conical cap which is displaced by the 

 young when it emerges. 



Stage 1. Length .5 mm, breadth one third of length ; antennae 

 stout, with numerous long spines; three segmented, the terminal 

 segment being about twice the combined length of the first and 

 second. Legs stout, and about as long as the insect. There are 

 simple spines arising directly from the body [pl.4, fig.2&], and 

 also much shorter, compound ones originating from cone-shaped 

 bases [pl.4, fig.2a]. Each abdominal segment bears on its lateral 

 margin a single somewhat trumpet-shaped, compound spine on 

 a conical base [pl.4, fig.3] . Two oval openings occur on the dorsal 

 line of the posterior margin of the third and fourth abdominal 

 segments. These may possibly be analogous to the odoriferous 

 glands which occur in certain other species of Heteroptera. 



e 



