EXPLANATION OF PLATE III. 
This, and the next two Plates, are photographs of Plates illustra- 
ting Vallisnieri’s Treatise on the “ Mosca de’ Rosai” = Arge pagana, 
Pz. (all more or less reduced as to size). 
Fias. 
1-3 show the insect at work on rose-stems. 
4 is intended to give an idea of the miniuteness of the excavating 
organ. 
5-6 show eggs lying in a double row in an excavation, 
7-8 show eggs in different stages. 
. Larvae feeding on the leaves, 
10. Cocoons formed by larvae. 
11. Larva magnified. 
12. Cocoons magnified. 
13. Cocoon split open and viewed from behind. 
14. Pupa. 
15. Cast skins. 
16. ¢ of the insect. 
17. Apparently some other species; ovipositing (according to the 
author) on the midribs of the leaves only. 
No) 
