58 



REMEDIES. 



The large holes made by this leaf -roller in the leaves of canna and 

 the rolled-up leaves, together with the excrement, which will be found 

 below the affected leaves, will serve to indicate its presence, and its 

 large size permits the control of the insect by hand-picking. Any of 

 the arsenicals will kill it, but their use is not always desirable because 

 of the presence of children in the vicinity and the fear of their being 

 poisoned. An ordinary spra^dng with an arsenical, preferably arse- 

 nate of lead combined with Bordeaux mixture, could, however, be 

 made without any real danger of j^oisoning. After an arsenical has 

 been used, Bordeaux mixture should be tried alone as a repellent. 



THE POND-LILY LEAF-BEETLE. 



(GaleruceUa nympJuete Linn.) 

 By F. H. Chittenden. 



During the first week of August, lOOtt, this leaf -beetle became so 

 abundant in the District of Columbia that it deserted its natural 

 food plants — aquatic species of the genera Nymphsea, Sagittaria, 

 Brasenia, and Nuphar — and attacked near-by plants of other botan- 

 ical families not at all related to those which form its normal food. 

 Mr. George B. Sudworth, of the Bureau of Forestry, reported the 

 species on basket willow, remarking that it appeared capable of 

 doing considerable damage to this plant. Mr. Sedgwick N. Lander 

 reported injury to beans. In both cases numerous living specimens 

 of the beetles were furnished. August 4 Mr. J. L. Reeves visited 

 Mr. Lander's place, and with little effort obtained a thousand or 

 more of the beetles by sweeping the infested plants. In confine- 

 ment the beetles fed for several weeks on the leaves of both willow 

 and bean, gnawing minute holes from the epidermis of the upper 

 surface, thereby producing the effect of fine network. 



This species is evidently of foreign origin and is now common 

 to both continents, and its semiaquatic habits are familiar to most 

 collectors. The writer has in mind another report, made August 3, 

 1899, by Mr. E. Balluff, of injury to a native pond lily (Nymphwa 

 sp.) growing on the grounds of the Executive Mansion at Wash- 

 ington. As this leaf-beetle does not appear to have been mentioned 

 hitherto in any publications of this Department, a short account may 

 be interesting. 



The species has frequently received mention under the name Gale- 

 Tuca sagittarice Gyll. It is related to the common cucumber beetles, 

 belonging to the same tribe, the Galerucinse, of the Chrysomelida^ 

 or leaf -beetles. The beetle (fig. 19) measures about one-fourth of 



