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UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



Here seventy-five acres of vines were completely stripped of their 

 foliage and scarcely an entire leaf was left on the area. As many as 

 one hundred and fifty full-grown larvae were counted on a single vine. 



In this case the owners were not aware of 

 the extent of the danger until the worms 

 had become nearly full grown, and most of 

 the damage done. At this time, however 

 a gang of about two hundred men was set 

 to work picking them off the vines, and 

 worms were carried away by the cartloads 

 'and burned. The species concerned here 

 was the Achemon Sphinx (Philampeles 

 achemon Drury), which is the most com- 

 mon species attacking the grapevine in 

 the State. 



These caterpillars may be found on the 

 vines late in May, and during the larger 

 part of June. The larva? are green in color, 

 like the leaf, and are therefore not readily 

 distinguishable when they are small. They 

 soon increase in size, however, and their 

 work on the leaves becomes noticeable. 

 While small, these larvae may be distin- 

 guished by a large horn on the posterior 

 end of the body, but this is lost during a molt before they are quite 

 full grown. 



Life History. These insects hibernate in the pupa or chrysalis stage, 

 and while in the ground may be distinguished as large cylindrical 

 objects of a dark brown color (Fig. 10). About the middle of May or 

 thereabouts they emerge from these chrysalids in the ground as large 

 and handsome moths (Fig. 11). These are the common moths that 

 poise over flowers at dusk. They are particularly attracted by 

 petunias, and it has been suggested that they might be captured in 

 large numbers about these flowers. 



The eggs are laid on the vine, and the larvae, upon hatching, begin 

 immediately to feed upon the grape foliage. Since they are voracious 

 feeders and grow to a very large size, three inches long or more, they 

 consume an enormous quantity of leaves. This year most of the larvae 

 were mature by the twentieth of June. When mature they repair to 

 the ground, where they pupate. In the vineyard already mentioned, 

 there appeared a second brood of caterpillars during the middle of 

 July. None of these reached their full growth, dying from some 

 unknown cause while they were but an inch and a half long. They 



FIG. 9. Hawk Moth larva. 

 (Philampeles achemon Drury.) 



