93 



insects. It shows some of the same peculiarities as to abundance and 

 abilit}" to do injury, but in some regions, as at Berkeley, is practically 

 unknown. 



The Eastern peach borer, as well as the curculio, has not found as 

 yet a home in California. The former has without doubt been man}' 

 times introduced into the State on nursery stock. Why the}^ have 

 not become acclimated is very difficult to luiderstand. We have a 

 native peach borer, Sannlmi jjacifica , belonging- to the same genus and 

 with the same habits, which in its distribution is quite as mysterious. 

 This insect makes its home in the neighborhood of San Jose and has 

 undoubtedly, even to a larger extent than the Eastern species, been 

 sent in nurserj- stock over the State, but it is still quite unknown 

 except in that one region, where it is quite as much a pest as the 

 S. exitiosa has ever been in the East. 



GKAPE INSECTS. 



Since California is the only region where the European grape is 

 grown, it is onh^ with us that the phylloxera is an important insect. 

 Vineyards have been destroyed over whole valleys, as occurred in 

 Europe, but the insect proves to be very much slower in spreading 

 than in Europe, which corresponds with the difference in life history 

 in California. The winged form, being produced only after long inter- 

 vals, apparently requires conditions which in most years do not occur. 



Next to the phylloxera the vine hopper {TyjMocyha comes) (ours is 

 a variet}^ somewhat intermediate between coloradensis and the typical 

 comes) is injurious only in the great valley and in the coast region 

 north and west of San Francisco Bay. In the early spring it often 

 comes in such immiense numbers as to cause the distortion of the young 

 leaves by the partial atrophy of the vine, causing them to have some- 

 thing the appearance of curled leaf lettuce. After the first leaves 

 have become mature they insert their slender curved eggs just under 

 the cuticle of the leaves beneath, and young are produced from then 

 on continuously till the leaves fall. By autumn, if nothing checks 

 them, they are more numerous than I have ever seen them in the East. 

 They are abundant enough every spring to easily destroy all the foliage 

 before the season is over, but through disease or other calamity, 

 exactly what, I have never been able to satisfy myself, their num- 

 bers are usually reduced so that it is possible to raise grapes. 



The remedy usually suggested for vine hoppers is winter "cleaning 

 up," but the usual practice in most parts of our vineyard districts is 

 to clean up more thoroughly than would be thought possible in the 

 East. It is certain that the clean vineyards are most injured by the 

 hoppers in the spring, although by midsummer little difference can be 

 noticed. 



Another vine hopper belonging to a different subfamily, and 1 



