BULLETIN 192. INSECTS INJURIOUS TO THE VINE. Ill 



The method of using the bisulfid is as follows: Place the cuttings in a 

 barrel, vat, or box made tight by means of a thick coat' of paint, or of 

 paper pasted on the inside. On top of the cuttings place a saucer or 

 other shallow dish, and into this pour the bisulfid of carbon. An ordi- 

 nary saucer will hold enough for a box three feet cube or a two-hun- 

 dred-gallon vat. For larger receptacles it is better to use two or more 

 saucers. Deeper vessels will not do, as the saturation is not sufficiently 

 rapid. After pouring the bisulfid into the saucer, cover the box with 

 an oiled canvas sheet or other tight-fitting cover, and allow to stand 

 for from forty-five to ninety minutes. At the end of this time there 

 should be a little of the bisulfid left. If it has all evaporated this is 

 proof that insufficient was used. No flame lights should be used, as 

 the liquid burns easily and the fumes form an explosive mixture with 

 the air. Care should be taken not to spill any of the liquid on the cut- 

 tings, as it may kill them. It is advisable to cut off about half an inch 

 of the lower end of the treated cuttings before planting, as the vapor 

 injures the open pith. Besides disinfecting the cuttings in this way, all 

 the packing material in which they come should be burned or, if valu- 

 able, dipped in boiling water. Practically, it is impossible to disinfect 

 rooted cuttings satisfactorily on account of the difficulty of killing all 

 the phylloxera without seriously injuring the vine roots. 



THE VINE HOPPER. 



(Typhlocyba comes Say.) 



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 injury. 

 Another larger species (Tettigonia atropunctata) occurs in these local- 

 ities and sometimes does considerable injury in the early part of the 

 season. 



The principal injury occasioned 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. The first evidence 

 of injury is a pale spot around the point of puncture. As these spots 

 become more numerous the leaf assumes a variegated appearance, due 

 to these pale spots, which indicates a lack of chlorophyll or green mat- 

 ter. As the injury increases the leaf becomes pale yellow in color, and 

 later dries up and falls to the ground. The leaves first attacked, and 

 those which suffer most throughout the season, are about the crown of 



