INSECTS DESTROYING FOLIAGE 473 



are in a blossom, it is probable that spraying may be omitted. If 

 they are more numerous, it is quite certain that spraying will be 

 required. 



Vine Hoppers. Very minute, yellowish, jumping insects infest- 

 ing grape-vines very early in the season, and multiplying rapidly. The 

 vine hopper (often called incorrectly the vine thrips) is the most 

 widely distributed and most uniformly present of all the grape insects 

 occurring in the State. It occurs in injurious numbers, however, 

 chiefly in the Sacramento and San Joaquin Valleys. It is also present 

 in the coast counties, but rarely in sufficient numbers to do much in- 

 jury. Another large species (Tettigonia atropunctata) occurs in these 

 localities and sometimes does considerable injury in the early part 

 of the season. The principal injury caused by this insect is due to 

 the extraction of the plant juices. These are sucked out by means 

 of a sharp beak or proboscis, which is inserted into the plant tissues. 



Control of the insect consists in keeping the vineyard clean of 

 weeds, which are the winter refuge of the pest thus reducing the 

 number ready for egg-laying on the vine-foliage. The next oppor- 

 tunity for effective work lies in killing the young insects, as they 

 appear from eggs placed in the leaf-tissue by the over-wintering 

 adults, before they get their wings. These young hoppers may be 

 killed by means of a spray applied to the under side of the leaves, 

 and this will be during May or the first part of June, depending 

 upon the season and locality. The exact time may be determined by 

 watching their development. When some of them have reached al- 

 most full size it is time to start the spraying. The spray to use is 

 soap-nicotine or nicodust, applied from below so as to strike the 

 under side of the leaves, for the spray will kill only such hoppers 

 as are hit. 



False Chinch-Bugs. Small, grayish-brown insects (about one- 

 eighth of an inch long when fully grown), which injure the vine 

 leaves. They drop to the ground when the vine is disturbed, and may 

 be caught or may be sprayed as for vine hoppers. 



Grasshoppers. These pests often invade orchard and vineyard, 

 and sometimes kill the plants outright by completely defoliating them. 

 This plague has been successfully met by the use of the arsenic and 

 bran remedy, prepared as already described for cut-worms. A table- 

 spoonful is thrown by the side of each vine or tree. If placed on 

 shingles about the vineyard, much of the poison not eaten may be 

 afterward gathered up and saved.* 



Red Spider and Other Mites. Very minute insects, usually dis- 

 cernible only with the aid of a magnifier, sometimes destroy the 

 leaves, causing them to lose their color and health by their inroads 

 upon the leaf surface. The red spider and yellow mite are conspicu- 



*For the protection of nurseries, orchards, and vineyards it is often necessary to 

 resort to various devices for excluding the grasshopper, or for destroying them upon 

 adjoining fields. Publications describing such devices are Bulletins 142, 170 and 192, 

 University Experiment Station, Berkeley. 



