254 



STATE BOARD OF AGRICULTURE. 



GARDEN WEB-WORM. 



(Loxostege sticticalis, Linn.) 



About the first of September, complaints were received from the vicinity of Three 

 Rivers, Mich., of a "worm" that made a web in the sugar beet leaves. In some places, 

 the entire crop was threatened by the ravages of tliese insects. E.vamples of these larvae 

 or caterpillars were examined and recognized as one of the garden web-worms of which 

 there are siveral species. Specimens received were about three-quarters of an inch in 

 length, pale yellowish-green or reddish-yellow in color, with black setose spots. The 

 head is yellowish-brown marked with brown spots; the prothoracic shield a little lighter 

 in color: dorsum of first two segments each bearing four black spots; segments, three 

 to eight. e,-ich bearing six black spots arranged in two triangles, one on each side; 

 segment nine having one median large spot with two lateral smaller ones; segment 

 ten having dorsal shield dirty yellow in color with brown spots. Under side of body 

 somewhat lighter and marked somewhat similarly with dirty spots. Each spot is 

 bordered indistinctly with pale. Legs pale with darker markings. Fig. 7. Specimen 

 received August 28. 



Fig. 7. Garden Weh-yform, Loxostege sticticalis. (Original.) 



On September 8 a visit was made to the place of Mr. S. M. Constantine, of Three 

 Rivers, Mich. The field visited was about a mile out of town and was thirty-six acres 

 in extent. The worms had been noticeable for about ten days or two weeks, working 

 very voraoious'y during the dry, hot season, but not doing so much harm since the 

 abundant rains had commenced. Nearly all the beet plants were affected and many 

 riddled. The caterpillars work, either in a web spun about the tender leaves at the 

 center of the plant or else on the underside of the larger leaves, where they are 

 either protected by a slight web or without any. The holes eaten by the caterpillars 

 are irregular in form, they vary in size, most of them being between one-fourth and 

 one irch in d'ameter. In places, the tops of the beets had entirely disappeared, but 

 the beets were easily seen by pulling aside the earth, most of them showing young 

 sprints ready to come forth with the first rain. The loss of foliage in this field was 

 considerab'e, about three acres be'ng entirely denuded. At the time when the field 

 was visited, the larvae were rapidly disappearing, though a few were to be found. 

 A quantity was collected and placed on fresh beet leaves to be reared in the labora- 

 tory. A number of adults were seen and one was captured: it was kindly determined 

 for me by M'ss Mary E. Mnrtfeldt, of Kirkwood, Mo. The larvae, on reaching full 

 growth, descend into the ground and spin tubes of silk therein, where they pass the 

 winter and emerire in the spring aa winged moths, ready to propagate their kind. Ac- 

 cording to Riley and Howard.* the insect probably is two-brooded. This insect is quite 

 troiihlesome in Nebraska, where it is well known. 



* Insect Life. Vol. V, p. 323. 



