80 



Table VIII. — Average Expected Increase in Yield of Winter Squashes. 



The average increase thus estimated is 4.5 tons per acre. The average wholesale 

 price of winter squashes during the sales-from-harvest period, September 1 to 

 November 15, appears to be $.03 per pound or $60. per ton.^ The vakie of the 

 expected average increase of 4.5 tons per acre is therefore $270. Subtracting from 

 this figure the cost of treatment leaves an estimated average net profit of from 

 $241.65 to $243.45 per acre. 



Summary. 



The squash vine borer is a serious native enemy of winter squashes and related 

 plants, for which no adequate remedy has previously been devised. The adult 

 insect is on the wing during July, la^dng its tiny, reddish eggs upon the squash 

 plants. The borers developing from these eggs cause the vines to droop and die 

 by tunneling in the stem and girdling the plant, throwing masses of yellow frass 

 out through holes in the stem, and causing the stem to rot. These larvae leave the 

 vines in the fall, and spin cocoons in the soil. A number of cultural practises, such 

 as fall plo^\ing of infested fields, adequate fertilization to promote growth and to 

 aid the secondary roots, and covering the runners with earth, have been recom- 

 mended, as has the practise of cutting the borers from infested vines. 



Experiments at tins Station indicate that nicotine suKate (Black-leaf "40"), at 

 the strength of 1 part in 100 parts of water, kills over 97 per cent of the eggs, and, 

 at the strength of 1 part in 250 parts of water, kills over 90 per cent of the eggs. 

 Spra^idng should be done four times, at weekly intervals beginning the first week 

 in July, using the stronger dosage with compressed air sprayers or similar machinery, 

 and the weaker dosage with barrel pumps or power spra3''ers. When thoroughly 

 done, spra5dng will largely ehminate borers from the fields. Complete extermina- 

 tion is then possible by cutting out the remaining borers during the middle of 

 August. 



The treatment is estimated to cost between $25. and $30. per thousand plants. 

 Thus intensive methods of culture and careful, economical sprajing must be the 

 rule where the treatment is to be found practicable on a commercial scale. How- 

 ever, estimates of various squash growers regarding the expected increase in yield 

 from borer-free plants indicate an average net profit of over $200. per acre from 

 the use of this treatment. For the home gardener, to whom cost of production is 

 a small item, it offers a read}'' means of successfullj^ fighting this most troublesome 

 enemy of squashes. 



1 Computed from the Boston Produce Market Reports, 1920-1923. 



