injurious and beneficial insects of California. 431 



.chiefly upon the tender young leaves, but also upon the stems and 

 older leaves. The eggs hatch in about four days and the larvae mature 

 in about two weeks. When feeding, which is done mostly at night, the 



Fig. 438. — Adult female of the melon worm, Diaphunia 

 hyalinata (Linn.). Enlarged three times. Specimen re- 

 ceived from Prof. R. I. Smith, West Raleigh, N. C. (Orig- 

 inal) 



caterpillars protect themselves by a thin web. When ready to pupate 

 they spin a white silken cocoon. The pupal stage lasts a little over a 

 week. The entire life cycle requires about one month. There are 

 three or four generations a year. 



Nature of Work. — The caterpillars destroy the foliage by eating 

 holes into the leaves or devouring them entirely. The young buds and 

 unfolding leaves are favorite portions of the plants, especially of the 

 young. They also eat holes into the young melons, cucumbers, etc., 

 thus destroying them for market purposes. 



Distribution. — The writer has been unable to find any records of 

 damage done in California by this pest, Professor C. W. Woodworth 

 records it as occurring in the State.' 104 



Food Plants. — Cushaw, cucumber, gourd, muskmelon, squash and 

 watermelon are commonly attacked by the melon worm. 



Control. — An important thing in the control of this pest is the 

 destruction of the vines, weeds and other rubbish in the fields by 

 burning in the fall and winter to kill the hibernating pupae. Deep fall 

 plowing also kills many of these. Planting early trap crops and spray- 

 ing them heavily with neutral lead arsenate (-4 pounds to 50 gallons 

 of water), or Paris green (H pounds to 50 gallons of water), will 

 destroy great numbers of the first broods. The cultivated crops should 

 be sprayed with lead arsenate paste, 3 pounds to 50 gallons of water, 

 lead arsenate powder, H pounds to 50 gallons of water, or a mixture 

 of ^ pound of Paris green and 1 pound of slaked lime to 50 gallons of 

 water. 305 In California the melon worm has not become a serious 

 pest and control measures so far have been unnecessary. 



304 Cal. Insects, p. 64, 1913. 



■""Watson, J. R., Press Bui. No. 209, Fla. Agrcl. Exp. Sta., p. 2, .1913. 



