78 



This species seems to be but single brooded, as no young larvre were 

 to be found after the first of June. As, however, the spinach beds 

 were rooted out before midsummer in all the gardens of the vicinity, I 

 can not be quite certain upon this point, but could not discover it on 

 beets or any of the native Chenopodiacew. The insect is one to which 

 it is difficult to apply insecticides, as the leaves which it attacks lie 

 close to the earth and it is, as a rule, on the under side. 



New Rose Slug. 

 (Cladiiis isomera Harris.) 



Early in August a friend, residing at St. Charles, Mo., sent me speci- 

 mens of a Tenthredinid larva that was working on her rose bushes, es- 

 pecially on climbers. This species, new to me, devours the entire sub- 

 stance of the leaves, gnawing into them large ragged holes and webbing 

 them together in the formation of its cocoons, greatly injuring and dis- 

 figuring the plants. It is characterized as follows: 



Mature larva 12 mm in length, 3 mm in diameter across thorax, from 

 whence it tapers very slightly backward ; form cylindrical. Color, pale 

 bluish-green, surface clothed with tufts of soft gray hairs. Head 

 opaque, dull whitish green, under the lens densely mottled with pale, 

 ferruginous, small black dot, above which is a rectangular ferruginous 

 spot on each side. Twenty legs, concolorous with general surface. 

 Spins up between folded leaf or between two leaves, in glassy, gummy, 

 pale brown cocoon, 7 mm long, of an oblong shape, flattened on both 

 sides against the inclosing leaves and with many gummy threads 

 spreading in every direction. 



Cocoons were formed in rearing cage August 20. Mies appeared 

 August 29. On the 2d of September I detected two in the act of ovi- 

 positing, with their well developed "saws "deeply buried, one in the 

 midrib, the other in the petiole of a fresh leaf. Two or three minutes 

 were occupied in the placing of an egg and each fly put in three or four 

 without pausing to rest. By carefully detaching the surrounding fibers 

 the egg was revealed. It is oblong, scarcely l mm in length, and almost 

 transparent. These eggs failed to hatch, probably for lack of fecun- 

 dation. 



From what I have learned from my friend, and infer from the habits of 

 the insect in the rearing cage, there are an indefinite number of broods 

 during the summer, and where it has become established it is therefore 

 a more serious pest of the Ci queen of flowers " than even Selandria 

 rosce. I do not doubt, however, that by killing off the earliest broods 

 with drenchings of an infusion of white hellebore, it could be kept 

 in check and by perseverance in the treatment eventually extermi- 

 nated. I have not been informed of its occurrence in any other part of 

 the State. 



