CONTROLLING GRAPE LEAF-HOPPERS IN 1912.* 



F. H. HALL. 



Many growers in the Chautauqua grape belt 

 Weather aids feared very extensive damage from leaf-hop- 

 in contest. pers in 1912, for millions of those insects 

 went into winter quarters in the fall of 1911. 

 In spite of seemingly unfavorable hibernating conditions — heavy 

 rains, sleet storms and wet snows to beat down the winter refuges 

 of the insects and severe cold to freeze them and keep them frozen 

 in their icy beds for months, no notable diminution of the numbers 

 was observed when they emerged in the spring. But the remark- 

 ably cold summer and the long-continued, wet weather in late 

 summer and early fall proved fatal to the nymphs, so that far less 

 damage was done to vineyards as a whole than was feared, though 

 many suffered severely and enough of the tiny pests matured and 

 went into hibernating quarters in the fall of 1912 to threaten 

 serious injury in many vineyards in 1913 unless active measures 

 are taken to combat them. 



No really new method was worked out in 

 Destroy 1912, but those recommended in Bulletin 



hibernating 314 proved very effective when thoroughly 

 quarters. applied. The experience of this season em- 



phasizes the necessity of destroying the winter 

 refuges of the insects, for whenever there were left undisturbed, 

 to shelter the hoppers, patches of weeds along the fences, a grassy 

 headland in the vineyard, a raspberry or blackberry patch adjoin- 

 ing it, underbrush with collected leaves in adjacent woodlands or 

 similar rubbish in ravines or swales near at hand, the tiny pests 

 would be found swarming in the edges of the vineyards, but gradu- 

 ally decreasing in number until at the center or opposite side there 

 might be few or none of them. Thorough cleaning up of such 

 places, especially by fire after the adult hoppers have gone into 

 winter quarters, is one of the most effective measures to be taken ; 

 for this not only destroys millions of the insects but it also re- 

 duces materially the supply of spring food plants and thereby 

 discourages the survivors when they emerge in the spring. No 

 collection of rubbish should be overlooked if it can with any ease 

 or safety be burned, for thousands of the pests may collect in a 

 small accumulation of leaves that have piled up about a broken- 



* Reprint of Popular Edition of Bulletin No. 359; see p. 287 for Bulletin. 



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