ENTOMOLOGY 57 



through the winter. These eggs are pearly white, and may be seen 

 as tiny specks on the under surface of the leaves. 



AYhen first hatched from the egg this mite, like the species pre- 

 viously treated, has only six legs, the fourth pair developing with 

 the first moult. They are somewhat smaller than the brown mite, 

 usually green in color while feeding upon the foliage of trees, with 

 minute black dots on the dorsum of the abdomen. When feeding 

 ceases in the fall, and they begin their downward migrations to the 

 soil, they become an orange, or red color. Unlike the brown mite, 

 the red spider has the power of spinning a web, and may easily 

 be detected, when prevalent, by the presence of these webs on the 

 foliage, or branches of infested trees. The appearance of injured 

 peach foliage is not unlike the appearance of that injured by the 

 brown mite, but is more inclined to turn yellow in patches. A sul- 

 phur spray, the same as is recommended for the brown mite, is 

 probably better than anything else that could be used during the 

 summer months-. (Bui. 169 Col. Exp. Sta.; Bui. 152 Col. Exp. Sta.) 



California Peach-Tree Borer. The most injurious insect in the 

 Santa Clara Valley is generally conceded to be the California poach- 

 tree borer. This insect is most abundant on peach and apricot trees, 

 or on prune trees growing on peach and plum roots. It bores into 

 the bark just beneath the surface of the ground, and is most easily 

 recognized by the very characteristic masses of gum that exude from 

 the tree at the point of attack. These borers often become so abund- 

 ant as to entirely girdle large trees, causing their death; and even 

 when not so deadly their attack seriously cripples the tree. The 

 labor necessary to dig out or otherwise destroy these insects amounts 

 to a great deal. This insect is best known in its winter quarters, be- 

 cause it is during the winter that practically all of the work for its 

 repression is done. 



With the commencement of the flow of the sap in the spring, 

 the older larvae proceed to the formation of their transformation tubes. 

 These are sometimes, indeed quite commonly, formed within the 

 burrows, especially if the amount of gum has not been excessive. 

 In other cases they will be upon the surface of the bark at, or near, 

 the mouth of the burrow. The most evident sign that the worm is 

 working in the bark of the tree is the exudation of a greater or less 

 mass of gum from the burrow. 



Ordinarily, there seems to be a great deal of variation in the 

 shape and direction of the burrow about as many burrowing up 

 as down. The general direction of the burrow is usually more nearly 

 vertical than horizontal, though a few may go directly around the 

 tree. The remedy, upon which the most dependence is placed in 

 fighting the Eastern peach-tree borer, is that of digging out the 

 worms. 



The time of the digging-out is almost always made a matter of 

 convenience, and the facts we have so far learned in regard to the life 

 history do not, as yet, prove that better results would follow a dif- 

 ferent practice. An important feature of the digging-out method is 

 that it is extremely difficult to find all, or even the larger worms, !ii a 



