1917] ECONOMIC ZOOLOGY ENTOMOLOGY. 155 



the amount of iujurious infestation on all the plats was comparatively small. 

 As a result tests made of several methods of irrigation failed to give conclu- 

 sive results. It is believed, however, that the results obtained in 1914 and 

 1915 indicate that control by irrigation will be effective only in years when 

 the precipitation is not above normal. 



In tests of plats of land, three of which had been in oats the previous year 

 and six in beetss, the infestation of the beets which followed the oats was 70.3 

 per cent and the percentage injuriously infested 4.7, while of those which 

 followed beets only 28.9 per cent were infested in any degree and only 0.73 

 per cent injuriously infested. These observations support the theory that the 

 root louse usually does not hibernate in old beet fields. 



The grape leaf -folder, J. F. Stbaxjss (U. S. Dept. Agr. Bui. 419 {1916), pp. 

 16, pis. 4, figs. 6). — The author reports studies of the life history and habits of 

 Dcsmia ftmeralis made in the vicinity of Washington, D. C, during the course 

 of two years. 



The injury which it causes, principally to the foliage of the grape, has fre- 

 quently been described since 1885. The larvje of the first brood have also 

 been observed to eat the blossoms and young fruit. As soon as it is large 

 enough the larva folds the leaf, exposing the undersurface, and within the 

 protection of this fold skeletonizes the upper surface. Later in the season 

 the skeletonized leaf dries up and exposes the fruit to the rays of the sun, 

 which in case of a severe attack renders the fruit unmerchantable. 



The pest occurs in all regions of the United States where wild or cultivated 

 grapes grow, and extends into a considerable portion of Canada, but it has 

 not as yet, with occasional exceptions, assumed the proportions of a pest of 

 much economic importance outside of the Central States between the latitudes 

 of 35 and 40°. It has been collected on the fox grape {Vitis labrusca), 

 southern fox grape (F. rotundifolia), V. cordifolia, the Virginia creeper 

 (Parthenocissns quinquefolia) , and two varieties of redbud {Cercis canadensis 

 and C. chinensis). 



At Washington, D. C, the greatest number of moths issued during the early 

 part of May, but adults have been obtained the latter part of April, through 

 May, and most of June. The eggs are usually deposited singly on the under- 

 side of the leaf, along the midrib or other veins, or in the angles formed by 

 the branching of the veins, and have also been found scattered over the grape 

 canes. The eggs hatch in from 8 to 10 days. The larva, which molts six 

 times, feeds almost continuously during the first three or four days between 

 molts, being especially active at night. In the latitude of Washington, there 

 are two generations each year. The majority of the first brood larvae pupate 

 during July, the average length of time passed in the larval stage being about 

 4 weeks. The larvte of the second brood begin to pupate in September and by 

 the middle of October few, if any, are to be found in the leaves in the latitude 

 of Washington. The full-growii larvse leave their shelters and drop to the 

 ground, where they transform among fallen leaves, trash, etc., and in the case 

 of the second brood, pass the winter as pupse. 



Seven hymenopterous and 3 dipterous parasites are recorded as having been 

 reared by the author from the grape leaf-folder, of which notes are given on 

 Apanteles canarsicc, Meteorus dimidiatus, Pardianlomella ibseni, Eabrobracon 

 johannseni, and Exorista pyste. 



As regards control measures it is stated that vineyards regularly sprayed 

 with arsenicals for the control of the grape rootworm, grape-berry moth, etc., 

 will be practically free from injury by the grape leaf-folder. Where it has 

 been troublesome in previous years, it is recommended that the vines be 



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