178 INTERNATIONAL CONGRESS OF VITICULTURE 



section of the country about Fresno. There are several different species of 

 cut worms, but the two most common occurring in the Fresno section 

 are probably "Paragrotis messoria," and "Peridroma margaritosa sauci." 

 Cut worms appear in the early spring and eat off the expanding buds. They 

 also feed upon the young leaves as they appear, but an early attack on the 

 swelling buds is when the most serious damage is done because the removal 

 of the principal buds destroys the fruit and the later buds usually produce 

 sterile shoots. The eggs are laid mostly on the stems of grasses near the 

 ground. The larvae hatching from these feed near the ground, and since they 

 work mostly at night they are not readily seen in their concealed situations 

 during the day. Since there is plenty of vegetation they do not do conspicu- 

 ous injury to the crop. A second generation appears in midsummer and 

 these feed upon the grass and other vegetation similarly to the first genera- 

 tion, and when winter sets in they are but partly grown. It is in this partly 

 grown larval stage which they spend the winter in a more or less dormant 

 condition. When the buds begin to expand on the vines and fruit trees, 

 these partly grown larvae become very active and climb into the vine or 

 fruit tree and very voraciously feed upon buds. 



The most satisfactory control measure for these insects is an application 

 of poisoned bait about the ground just at the base of the vine. During the 

 day the worms will be found just below the surface at the base of the vine 

 and come out at night to feed upon the buds or leaves. When they emerge 

 at night they will come in contact with the poisoned bait and will be satisfied 

 with that rather than climbing into the vine. In the case of vines which 

 are pruned high and where there is more or less trunk to the vine, the worms 

 will not always go down to the ground to remain concealed during the day, 

 but will secrete themselves under the bark on the trunk of the vine. In 

 such cases it is necessary to apply the poisoned bait in the crotch of the vine 

 as well as on the ground. 



In certain limited sections and during occasional years, vineyardists are 

 obliged to combat the army worm. This is an insect very closely related to 

 the cut worms just mentioned, but is a distinct species, being the well known 

 army worm which occurs more abundantly in the Eastern States than in 

 California. The second generation of the army worm in California appears 

 about the first week in August, and since at this time the grain fields upon 

 which it has been feeding previously, afford very little succulent growth, 

 they leave such situations and acquire the migratory habit, and march off 

 in a definite direction in enormous numbers. Where an outbreak of these 

 army worms is discovered in a neighboring grain field, they can be very com- 

 pletely prevented from entering the vineyard by plowing a furrow with the 

 vertical side of the furrow next to the vineyard to be protected. The army 

 worms marching into this furrow, will be unable to ascend the vertical side 

 and they may be killed in this furrow in any way which seems most feasible. 

 Usually holes are dug every twenty or thirty feet in the furrow and the 

 worms, unable to scale the side, will crawl along the furrow and drop into 

 these holes where they may be destroyed by sprinkling with a little gasoline 

 and dropping in a lighted match. If they are already in a portion of the 

 vineyard, the furrow may be made in the same way to protect the portion 

 not yet reached. The vines already attacked can scarcely be saved from 

 defoliation because of the very great numbers of the worms, but they may 



