14 
BULLETIN 98 . 
About the 10th of August, 1899, the worms of this insect 
seemed suddenly to appear in fields of sugar beets about Grand 
Junction. Many acres of beets had their tops all eaten away and 
then the worms turned their attention to the beets themselves 
eating them out below the crown. Mr. H. H. Griffin, then at 
Rocky Ford, reported this insect as doing some injury to experi¬ 
mental plats of sugar beets in that locality. Since 1900 this 
worm has been reported as doing some injury to beets in the 
Arkansas valley, but it lias not been reported in injurious numbers 
since 1899 at Grand Junction. 
LIFE HABITS OF THE INSECT. 
The worms that were so numerous in the Grand Valley in 
1899, burrowed into the ground to the depth of about an inch 
when they became full fed, formed an earthen cell about them¬ 
selves, apparently without spinning any cocoon, and from these 
cells the moths appeared in great numbers during the latter part 
of August and September. The moths appeared so late that it 
seems probable that they hibernate during the winter in that 
stage, but of this I have 110 positive knowledge. I was shown in¬ 
juries done to beets by this worm during June of the same season 
at Grand Junction, so there are two, and possibly three broods of 
this insect in a year. 
I11 June 1900 Mr. E. I). Ball visited Rocky Ford where this 
insect was doing some injury and learned that the worms began 
hatching about June 1st, and that the moths were noticed in the 
fields two weeks prior to that date. He also noted that early 
planted beets suffered most and the application of Paris green had 
proven a satisfactory remedy*. 
The following life history notes are extracted from breeding 
cage records kept by Mr. Ball upon the development of worms of 
all sizes taken by him at Las Animas, July 16, 1901, while an 
assistant in this department: 
July 22, 1 chrysalis, (or pupa.) 
July 24, another worm in earthen cell ready to pupate. 
July 27, several worms have pupated in the last few days. 
July 29, all have changed to pupa?. 
Aug. 5, first moth emerged. 
Aug. 6, another moth. 
Aug. 7, another moth and a parasite from July 22, pupa. 
Aug. 8 to 14, one to 4 moths each day. 
Aug. 9, four moths that hatched today were put in a cage with 
sweetened water which they ate freely. 
Aug. 14, 552 eggs have been laid upon under side of leaves and 
upon sides of cage. They are in groups of from 12 to 50 and each group 
is coated with a white downy secretion. 
Aug. 15, some of the eggs are looking darker. 
*See 13th Annual Report of Colo. Agrl. Uxp. Sta. p 128. 
