March, 1919.] WEISS AND DlCKERSOX : IxSECTS OF ROSE-MALLOW. U 



habitat is the swamp or marsh it appears to thrive just as well in 

 the normal soil found in the nurseries where it has been noted to 

 vary considerably, in some instances producing flowers of a very 

 large size. 



Rhaeboscelis tenuis Lee. 



Rliccboscelis tenuis Lee, was described by Le Conte in 1863 in the 

 Smithsonian Miscellaneous Contributions, from specimens collected 

 by Mr. Ulke in Maryland and by Mr. Benj. D. Walsh in Illinois. 

 Since then it has been recorded in very few local lists and so far as 

 we are aware there has been very little or no indication of its habits 

 or food plant. In Ulke's Washington list it is recorded as being 

 taken on oak, but a more nearly accurate suggestion is made in 

 Smith's List of the Insects of New Jersey (1909), where Mr. Wenzel 

 records it from Anglesea in July on low plants in swampy glades. 



Our attention was first attracted to this insect early in the summer 

 of 19 1 7 when it was observed in the Bobbink and Atkins nursery at 

 Rutherford feeding on the leaves of the swamp rose-mallow. It was 

 apparent that this was the food plant of the adult and perhaps that 

 of the larva as well and further investigations later in the season 

 proved this surmise to be correct. 



The adults make their appearance about the middle of May and 

 continue in evidence until the latter part of July. By early August 

 they have disappeared. The eggs of this species have not been 

 observed, but it is evident from a study of the larval burrows that the 

 eggs are deposited in the upper part of the stems or even in the leaf 

 petioles, probably inserted into the bark tissue. From each egg there 

 develops an agrilid-like larva save perhaps that it is somewhat more 

 elongate as will be noted in the description which follows. This 

 larva burrows down the stem into the pith or between the pith and 

 wood, making a characteristic winding or zig-zag gallery. In some 

 cases it appeared that the larvae retraced and burrowed up the stem 

 again as pupal chambers in some cases were found pretty well up the 

 stem, too high for the larva to have reached the point by simply bur- 

 rowing downward and not enough distance having been covered for 

 the larva to have reached its full development. 



There is no external evidence on the stem to show the presence 

 of the larva within, but where burrowing occurs in the leaf petiole 



