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Kansas State Board of Agriculture. 



GARDEN WEBWORM. 



(Loxostege similalis Gn.) 



Small, green, black-dotted web-spinning caterpillars, appearing in June, 

 July and August, and binding up the alfalfa plants with webs. 



Distribution. 



Although this insect occurs throughout the United States, it is most 

 serious in the central Mississippi states. Several times it has proven a 

 serious enemy to alfalfa in this state. The larvae feed normally on the 

 pigweed or careless weed, from which they sometimes receive the local 

 name "careless worm." Usually it is only when they become abundant on 

 the weeds that they migrate from them to attack crops, such as alfalfa, 

 corn and garden truck. 



Habits and Life History. 



The moth is yellowish, buff, or grayish-brown in color, with a wing 

 expanse of about three-quarters of an inch. The eggs, which are laid on 



the food plants, soon hatch, and the 

 tiny worms begin feeding. In feed- 

 ing the worms spin a fine web, which 

 gradually envelops the plant, of 

 which nothing is left but the skeleton 

 of the leaves when the worms are 

 abundant. The worms vary in color 

 from pale and greenish-yellow to 

 dark yellow, and are marked with 

 numerous black dots. (Fig. 332.) 

 The worms become full grown in 

 about three weeks in summer, when 

 they descend to the ground and 

 pupate in small silken cells on or 

 just below the surface. The moths 



emerge in about one week, so that In midsummer the complete life cycle 

 occupies about one month. In Kansas there are three or four genera- 

 tions a year, the last generation passing the winter either as larvae or 

 pupae in silken-lined cocoons in the soil. 



Methods of Control. 



Usually the farmer does not notice the trouble until the plants are 

 covered with webs and are seriously injured. Just as soon as the worms 

 are noticed the alfalfa should be cut in order to save as much of it as pos- 

 sible for hay. If it is full of the web and the droppings of the worms it 

 should not be fed to horses, but may be fed to cattle. In raking and 

 handling the hay many of the worms will be killed, while others will 

 perish in the hay. 



The plowing of infested weed fields in late fall or winter and thorough 

 disking of alfalfa will be found largely to control the pest. When it 

 appears on garden crops it may be readily destroyed by at once spraying 

 or dusting with Paris green or lead arsenate. The destruction of the 

 weeds upon which it feeds is very important in preventing the undue in- 

 crease of the pest. 



Fia. 332. Garden webworm (Loxo- 

 stege similalis). a, male moth; b, c, 

 larvae ; d, anal segment of same ; e, ab- 

 dominal segment of same from side; /, 

 pupa; g, tip of abdomen of same; a, b, c, 

 f, somewhat enlarged; d, e, g, more en- 

 larged. (After Riley and Chittenden, U. 

 S. Dept. Agr.) 



