-22 PAPERS OX INSECTS AFFECTING VEGETABLES. 



sell, at Cutler, Fla.. March 23-29, 1909. It is interesting to remark 

 that Mr. H. O. Marsh has found this species ver}~ destructive to sugar 

 beets in Hawaii, and has made a special study of it for the Bureau 

 of Entomology. 



An agromyzid fly was reared February 17, 1909, with this beet 

 webworm from material received from Mr. H. M. Russell on beets 

 and Amaranthus collected at Boynton, Fla. 



P(gomya rujiceps Stein, an anthomyiid fly, was reared under prac- 

 tically the same conditions as the moth Hymcnia fascialis Cram., 

 above mentioned. 



REMEDIES. 



The remedies that have been advised for use against the garden 

 webworm (Loxostege similalis Guen.) should be found about equally 

 effective against the present species. In any case their use is advised 

 until more is learned of the habits of the southern beet webworm. 

 These remedies are given below. 



Paris r/zw??.— Paris green is applied at the rate of 1 pound to from 

 75 to 100 gallons of water, or dry, distributed with a powder gun, as 

 practiced in the South. The latter method, however, is inferior to 

 spraying. Since the two sjieeies share common natural food plants 

 (Amaranthus), the usual care should be exercised to avoid planting 

 beets in fields which have grown up in this weed until after thorough 

 fall or spring plowing. 



The experience which Mr. H. O. Marsh has had with the related 

 Hawaiian webworm conclusively shows the value of Paris green. He 

 states, in brief, that a spray of Paris green at the rate of 2 pounds of 

 the arsenical and whale-oil soap, 8 pounds in 100 gallons of water, 

 proved absolutely effective and did no injury to the plants on which 

 it was applied. The spray was applied to the underside of beet 

 leaves. 1 More complete information hi regard to this is given in 

 Part I of the present bulletin. 



It should be added that a mixture composed of nicotine sulphate, 

 1 fluid ounce, with whale-oil soap, 4 ounces, in 4 gallons of water, 

 was used by Mr. Marsh against a number of noxious lepidopterous 

 larva?, and although this formula was not tested on the Hawaiian 

 beet webworm, he believes that it would prove entirely effective. 



Dragging the log. — In the case of a bad attack of the garden web- 

 worm in Oklahoma in 1903, a satisfactory barrier to migration was 

 employed, consisting of a dust furrow in which a log was dragged. 

 This might be used in case the webworm under discussion should 

 occur in great numbers before its presence is discovered — something 

 that is likely to happen, as in the case of species of related habits. 



i For some reason arsenate of lead applied to both sides of Amaranthus leaves was found ineffective and 

 no explanation could be made of this, but the chemical was probably not pure. 



o 



