Pests and Diseases of Plants 245 



tion agair.st this and more or less of a cure also. Furthermore, 

 borers may be the cause, which can be determined bj' examining 

 the points where the gum exudes, seeing if any wood grains are 

 present. These borers should be dug out and whitewash applied, 

 which latter also protects against this trouble. Lastly, your ground 

 may be drying out, which also you can determine and remedy. 



Borers in Olive Twigs. 



There are quite a number of olive trees in this locality that have 

 something ivrong with them. They make a growth of iii>e or six inches 

 and the center tzvig dies back, then it sprouts out at the sides and makes 

 another growth in the same way. This makes a thick bush instead of 

 the tree coining up as it should. 



The dying back is caused by a beetle which bores into the twigs. 

 The twigs above the point where the beetle enters dies and then, 

 of course, buds come out from healthy wood below. No treatment 

 has been devised against it, though its breeding ground is limited 

 if all dead wood and brush and litter is cleaned up and twigs are 

 cut ofif below the point of injury whenever the work of the insect 

 is seen. 



Raspberry Cane Borer, 



Can you tell me zvhat to do for my Loganberries and raspberries? 

 A small worm got into them in the nezv grozvth of zvood last summer, 

 right in the tips of the nezv growth of zvood, and then worked down 

 through the pith of the wood, and as fast as they worked down the 

 can zvilted. 



This is the raspberry horn-tail, or the cane-borer. The adults 

 are wasp-like insects about a half-inch long and very active. They 

 come out of the canes in spring and the females soon lay eggs in 

 the tender tips of the young shoots. These eggs soon hatch and 

 the larvae eat their way up toward the tip, which causes it to wither 

 and die. It is this injury that causes much notice. As the tip dies, 

 the larvae turn and go down into the canes, as in the sample sent, 

 also injuring them greatly, though possibly not killing them for 

 some time. The only way to attack them is to pinch the spots where 

 the eggs were laid; then those that escape and cause the tips to 

 wilt should be destroyed by cutting off the tips below the point of 

 injury or cutting off the canes when they show damage. Likewise, 

 the insects work on the wild rose, and cutting all those out around 

 a place will prevent enough adults from developing to permit little 

 damage to be done, always provided the berries are well looked 

 after. 



Control of Red Spider. 



Can you give directions for the prcz'cntion of injury by the red spider 

 to almond and other trees in the Sacramento valley? 



The red spider on almond and prune trees is usually controlled 

 by the thorough application of dry sulphur to the foliage. On 

 almonds the first sulphuring should be done as soon as the leaves 



