100 THE RAISIN INDUSTRY. 



RED SPIDER. 



Characteristics. Red or yellow mites are quite frequently injurious 

 to grapevines. These mites are small, almost microscopical, and 

 appear in enormous quantities on both sides of the leaves, especially, 

 however, on their under side. They cover the leaves, and even the 

 ground of the vineyard, with a thick cobweb, in which they live and 

 hatch. Dry air and heat promote the wellbeing of the mites, and 

 hasten the injury they do to the vine leaves, which soon dry up and 

 check the growth of the vines. On the contrary, dew and moisture 

 destroy the red mites in a short time, and in places near the coast they 

 are seldom very injurious. 



Remedies. Sprays of various kinds, such as whale-oil soap, resin 

 sprays, etc., have been used. Frequent spraying with pure water 

 will destroy the mites, but they will multiply again if the climate 

 is favorable. The best success is had with a spray of a compound 

 known as the I X I/ compound, which is used in the proportion of 

 five pounds of the compound to thirty gallons of water. One good 

 spray will destroy both the mites and their eggs. 



CATERPILLARS. 



Characteristics. The caterpillars which trouble the raisin grapes are 

 confined to three or four kinds. The most common and also the most 

 destructive are the very large larvae of the sphinx moth. The com- 

 mon grapevine sphinx (Philampelus ach&moii) is a large larva, incor- 

 rectly, called a worm, which is, when full grown, over three inches 

 long. The color varies from bluish green to brown, with several 

 lighter stripes on each side. The head is truncate, and the tail is 

 furnished with a curved horn. The pupa hibernates in the soil below the 

 vines, and is about half the size of the full-grown caterpillar. The full- 

 grown moth is about two inches long by two and one-half inches 

 between the outstretched wings. The eggs are laid by the moths on 

 the leaves of the vines. Two broods of caterpillars appear yearly 

 under favorable conditions, or else only one brood, which genera.ly 

 appears in the end of July. The caterpillars grow with great rapidity, 

 and attain their full size in a few weeks. The pupcz hibernate in the 

 soil and hatch the following summer. 



Another large grapevine caterpillar is the Deilephila striata, which 

 is about the same size as the Ach&mon. The moth has more pointed 

 wings, with narrow stripes, and the larva is brighter colored, often 

 yellowish green, with several colored stripes on the sides. The eggs 

 are not laid on the vines, but on the weeds,on the vacant lands outside 

 the vineyard, especially on species of Ep&obium, but also on other 

 weeds, and they hatch and feed on them. The caterpillars feed in 

 ordinary years only on the weeds on which they are bred, but in other 

 years which are especially favorable to their enormous increase they 

 migrate to the vineyards and feed on the vines at the most alarming 

 rate. The caterpillars of both the above large moths vary in color 

 from green to brown or violet brown, but as a rule the Deilephila is 



