r ■ 



THE GKAPE-BEERY MOTH. 17 



are hatching in large numbers, will result in a considerable reduction 

 in the injury wrought to the grape berries by this pest. 



Recommendations offered for the control of this insect in regard 

 to the time and manner of making spray applications are based upon 

 the data obtained in the study of the life history and habits of the 

 grape-berry moth during this investigation, correlated with the field 

 experiments and observations covering that period. Since these life- 

 history studies have shown considerable deviations from those previ- 

 ously recorded in regard to the time of appearance of certain stages 

 of the insect and in the number of broods each season, it has been 

 necessary to revise our ideas somewhat as to the relative importance 

 of the spray applications formerly recommended; and since suitable 

 opportunities have not presented themselves for a thorough trial of 

 this revised spray schedule, some of the recommendations along this 

 line are offered rather in the form of suggestions than as definitely 

 demonstrated and proved methods. 



HISTORY. 



The American species, Polychrosis viteana, was first described by 

 Clemens in 1860, in the Proceedings of the Philadelphia Academy of 

 Natural Sciences. In addition to a description of the adult moth 

 Clemens makes some statements as to the habits and food plants of 

 the larva. (See discussion under Food Plants, p. 20.) 



In 1869 Packard, in his " Guide to the Study of Insects," has de- 

 scribed this insect under the name of PentJiina vitivorana. In a foot- 

 note, however, he states, "It is the Lobesia botrana of southern 

 Europe according to Prof. Zeller." 



About this date Dr. C. V. Riley sent some specimens of the Ameri- 

 can-reared species to Mr. P. C. Zeller, of Stettin, Prussia, who iden- 

 tified them as the European species Lobesia botrana and Packard's 

 footnote quoted above is doubtless the result of Zeller's identifica- 

 tion of the American specimens sent to Europe by Dr. Riley. 



From 1870 until 1903 American entomologists accepted the state- 

 xnent of Zeller that the grape-berry moth found in this country was 

 of European origin. In 1903, however, the study of this insect was 

 taken up by Prof. M. V. Slingerland in the vineyards of Chautauqua 

 County, N. Y. Owing chiefly to some variation in the habits of 

 hibernation of the American species from that of the European 

 species — namely, that it makes its overwintering cocoons on fallen 

 leaves, whereas cocoons of the European species are found upon the 

 trellis posts and the trunks of the vines — and since in addition to 

 this the American grape-berry moth is quite common in the fruit of 

 wild grapevines growing at considerable distances from cultivated 

 grapevines, Prof. Slingerland was led to surmise that the American 

 grape-berry moth is a native American species. 

 60141°— Bull. 116, pt 2—12 2 



