U. S. D. A., B. E. Bui. 109, Part II. T. C. & S. P. I. I., November 11, 1911. 
PAPERS ON INSECTS AFFECTING VEGETABLES. 
THE SOUTHERN BEET WEBWORM. 
{Paehyzancla bipunctalis Fab.) 
By F. H. Chittexden, Sc. D., 
In Charge of Truck Crop and Stored Product Insect Investigations. 
INJURIOUS OCCURRENCES AND NOTES ON HABITS. 
On September 24, 1906, the Bureau of Entomology obtained from 
Mr. F. W. Roeding, Wichita Falls, Tex., the larvae, pupae, and adults 
of the pyralid moth Paehyzancla bipunctalis Fab., which had been 
found operating on foliage of table beets in that vicinity. One larva 
transformed to pupa On September 25, and the adult issued October 
3, the pupal period thus having occupied eight days in an average tem- 
perature of about 70° F. From this lot imagos continued to issue 
until October 2, and a larva matured October 10 which would have 
produced an imago about October 30. 
During October, 1907, Mr. H. M. Russell observed larvae at Dade 
City, Fla., on beet tops from 6 to 8 inches high, " webbing up" the 
leaves with the edges of the leaves folded together or joining two or 
more leaves to make a nest in which to hide. From this conceal- 
ment they emerge and eat the leaf cells composing it, usually 
leaving the leaf skeletonized or very thin. In these nest-forming 
and leaf-eating habits the insect resembles the related Pyraustidee. 
Mr. E. B. Embry, located at Dade City, Fla., stated that the larvae 
of this species had injured the foliage of small beets so badly as to 
reduce his crop about 50 per cent. As late in the season as November 
29, the web worm larvae were found in another locality at Dade City, 
some of which showed parasitism. In January, 1909, larvae were 
observed attacking beets at Boynton, Fla., and in March, beets at 
Miami, Fla. 
From web worm material obtained October 18, one pupated October 
23, and the moth issued November 8. Another larva pupated 
November 6 and the adult issued on November 21, thus indicating a 
pupal period covering from 15 to 16 days, in the latitude of Washing- 
ton, D. C. In another case the pupal stage lasted from December 31 
to January 22, or a total period of 23 days. The temperature at 
Washington was moderatelv cold. 
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