430 INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



Nature of Work. — Burrows are made in the middle of the stems and 

 leaf stalks, which are occasionally cut off, causing the leaves to wilt 

 and the plants to die. Many larvae may inhabit a single plant, so the 

 signs of their work are sometimes very sudden. The white frass at 

 the entrance of the burrows is an indication of the presence of the 

 borer. Late crops are injured most. Gourds are often burrowed into. 



Distribution. — Prof. C. W. Woodworth 301 records this as a California 

 insect. Its distribution within the State is evidently limited. It occurs 

 in the United States, Canada, Mexico, Guatemala, Panama, Brazil and 

 Argentine Republic, as recorded by Dr. Dyar. 



Food Plants. 1 "- — Cantaloupes, cucumber, wild balsam apple {Ecliino- 

 cystis lobata), gourdj muskmelon, pumpkin, squash and watermelon. 

 The late varieties of squashes (Hubbard, marrow, cymlings, etc.) are 

 injured most. 



Control. — Planting early trap crops of summer squash and other 

 early varieties between the rows of the later varieties and burning these 

 to destroy larva? and eggs will greatly reduce infestation of the main 

 crops. Plantings in July are not usually severely attacked. It is 

 also advisable to kill adult moths which are sluggish and easily cap- 

 tured late in the evening. They are usually to be found upon the upper 

 surface of the leaves. All vines should be burned in the fall, as early 

 as possible, to destroy any of the larvae which have not gone into the 

 ground to pass the winter. Deep fall and spring plowing will bury 

 the over-wintering pupa?, so that the adults can not make their way out 

 in the spring. Burying the vines at the nodes, so that roots will be sent 

 out to support the shoots in case the main stalks are injured at the 

 base, is also recommended. If only a small patch is infested the vines 

 may be saved by digging out the borers, avoiding planting on or near 

 infested soil. 



THE MELON WORM 303 



Didphania hyaUnata (Linnaeus) (Family Pyralidae) 



[Glyphodes hyaUnata (Linnaeus)] 



(Phalama hyaUnata Linnaeus) 



(Fig. 43 8) 



Description. — The moths are beautiful, pearly-white with the front 

 margin and borders of the wings, tuft at the tip of the abdomen, the 

 head, anterior half of the thorax and ventral surface a rich brown. 

 The wing expanse is about 1 inch, the length of the body \ inch. The 

 eggs are small, pearly-white and laid in masses of from two to six. The 

 larvae or caterpillars are pale yellow with brown head and two white 

 longitudinal stripes down the back. When full-grown they are about 

 1] inches long. The pupae are rich brown in color and about § inch 

 long. They are enclosed in thin white cocoons spun in the folded edges 

 of the green leaves. 



Life History. — The winter is passed in the pupal stages, usually 

 upon the old vines or in rubbish or protected places about the fields. 

 Adults begin to emerge in May, June and July and lay their eggs 



301 Cal. Insects, p. 62, 1913. 



••"Chittenden, P. H.. Cir. No. 38, Bur. Ent. U. S. Dept. Agric, pp. 2-3, 1908. 

 '"Smith. R. I.. Bui. No. 206. N. C. Agrel. Exp. Sta., 1910. and Bui. No. 214, N. C. 

 Agrcl. Exp. Sta., 1911 



