MASS. EXPERIMENT STATION BULLETIN' 409 



Table 2. — Length of Life of the Larva of 



THE Grape Plume Moth. 



Waltham, Mass. 



Pupation 



When ready to pupate, the mature lar\a suspends itself posteriorly from the 

 leaf, usually within the web of its nest. Frequently it hangs downward from 

 a leaf or tendril but it may be suspended at any angle from the surface. The 

 pupation period lasts about 12 days but this may be extended by cool weather 

 as in 1940 when an average of 17.13 days was required and one insect remained 

 in. the pupa stage for 27 days. The pupation records are shown in Table 3. 



Table 3. — Length of Pupation Period of the 

 Grape Plume Moth. ^ 



Waltham, Mass. 



Number of Days 



Year — ■ — ■ — 



Ma.ximum Minimum Optimum Average 



1938 13 9 12 11.67 



1939 13 10 12 11.90 



1940 27 12 15 17.13 



Average for the three \ears 12.64 



SEASONAL HISTORY 



Contrary to several published reports (9) (12), the grape plume moth has one 

 generation annually in Massachusetts. The insect lives from mid-July to mid- 

 May, including the entire winter, as a completely developed but unhatched larva. 



Seasonal History of the Grape Plume Moth. 



