222 STATE BOARD OF AaRICULTURB ' 



reported at Oassopolis, Michigan. Specimens were sent in, which left 

 no doubt as to the identity of the louse. On the 26th of May we received 

 specimens from Allegan and on the 25th from Paw Paw, where the louse 

 appeared in enormous numbers on alfalfa and threatened the life of 

 the plants. On the 1st, inst. (1 June) Mr. W. R. Eoach of the Roach 

 Canning Company, Grand Rapids, informed us by telephone that the 

 lice were present at Kent City and vicinity in great numbers. Thus our 

 conclusions as to the rate of progress of the season appear to be justified. 



Now, as tot he seriousness of the attack. On the 1st day of June, 

 we were informed that on the 26th and 27th of May, the number of 

 lice had noticeably decreased in the Paw PaAv region, and in connection 

 with this it is interesting to note that Mr. John Harman, Extension 

 Specialist in this department, reports, after a visit to several places in 

 the region of Paw Paw and Cassopolis, that the dwindling of the lice 

 was apparently aided b}^ four agents, namely: a large number of lady- 

 birds, two species of hymenopterous parasites, one of which is Lysiphlc- 

 hus, and to a fungus disease which we identified as Empusa aphidis. 



Of course, the onslaught by the natural enemies of this pest was 

 favored by the w^eather which had in the meantime become warm and 

 summery, it having been, previously, quite cool, the season being back- 

 ward. 



The appearance of the pea-louse in our alfalfa fields exactly at the 

 time computed appears significant. 



GRArE BERRY MOTH, 



PolycTirosis viteana. 



The summer of 1922 witnessed the most serious outbreak of grape- 

 berry moth that has ever occurred in Michigan, since our grape belt 

 took its place among the real i^roducers. 



The lite history of this insect must be somewhat variable. We belie\'0 

 that three generations occurred, all of which overlapped noticeably. 

 The pupal stage should be passed in little flaps cut in the leaves but care- 

 ful search failed to reveal more than a very few such flaps. This led 

 us to suspect the presence of the European species. However, all speci- 

 mens bred from the grape belt proved to be the common American species. 



Our recommendations provided for a spray just before the blossoms 

 open, another when the fruit is nicely set, and another spray just be- 

 fore the grapes closed in the cluster, as late as possible before most 

 of the berries touch and become tightly packed in the cluster. We also 

 recommend that the spray be shot upward from below under good 

 pressure and with liberality. This is possible only when the spraying 

 is done by the trailer method, that is, — when a man follows the spray 

 rig with an extension and a nozzle set at right angles to the extension. 

 This is held under the fruit and the spray is shot upward so as to com- 

 pletely coat each bunch of developing grapes. We also recommended the 

 application of a fourth spray, two weeks after the one just mentioned. 

 AVe intended this as an emergency measure and not for general practice. 



The cleaning up of brush and trash was strongly recommended since 

 the injury was uniformly the worst on the borders of vineyards. This 

 also helps ot control the leafhopper which was present in large numbers. 



