142 



STATE BOARD OF AGRICULTURE. 



increasing in diiinu-tcv until llicy attain full size at tlic pt'iipiuMy. The eggs are laid 

 along the sides of the hrood-ciianiher and the young grubs, on hatching, commence 

 boring in the direction indicated, the regular increase in size being due to the growth 

 of the grubs as they get further and further away from the ])arental burrow. When 

 the grubs have attained tlieir full size, they go a little deeper and pupate, coming out. 

 in time, through holes bored to the surface, as adult, winged lieetles. 



In time, the ellVet on the tree of numbers of these borers is very marked, usually 

 leading to its deatli. 



The beetle (Fig l!t| that causes all this trouble looks innocent enough, little more 



Fig. 19. Fruit Bark-Beetle, Scolytus rrir/iUosus. (Original.) 



than one-sixtoeiitli of an inch in length, almost black, somewhat cylindrical, and covered 

 with minute punctures or pits. It belongs to the family of bark-borers or scolytidae. 

 The insignificant size of these little fellows almost makes them appear unworthy of 

 notice, but we have most of us learned by this time that the very small pests are 

 the most difficult to control, because they are usually present in such great numbers. 



REMEDIES. 



Most members of this family of insects greatly prefer to work in trees that are 

 dying or that for some reason are not in a very vigorous condition at the time; hence 

 when this insect is present it is imperative to keep trees especially well fertilized and 

 in prime condition. When a tree is badly attacked, the cheapest course is usually 

 to remove and burn it, as it merely serves to breed the pests and to furnish a source of 

 infestation for the rest of the trees. Advantage may be taken of the preference of 

 the beetles for sickly or dying trees, and if any worthless or comparatively poor trees 

 are in the orchard, they may be girdled in midsummer 'in order to ind\ice the beetles 

 to take possession. This will serve as a trap to entice numbers of the beetles to the 

 same spot. Of course the tree will have to be cut down and burned before the beetles 

 emerge, which is said to take place in other states about the middle of June. The 

 insect matures several broods during the course of a season. 



When a tree is slightly attacked, the bark may be pared out where the tunnels 

 occur, or the tree may be coated with whitewash to which a little Paris green has 

 been added; this will tend to prevent any further infestation, and if the practice is 

 persistently followed up it is said to be very useful as a preventive. The wash should 

 be applied to all the trunks and limbs in the orchard. 



Prof. John B. Smith, Entomologist of the New Jersey State Experiment Station, 

 has carried on a number of successful experiments with hydraulic cement and milk 

 for the peach-borer and it may be possible to use it against the fruit-bark beetle. The 

 cement, when used with milk, makes a thin hard shell around the ])arts treated, which 

 prevents the laying of the eggs. While it is not perfectly safe to recommend this 

 remedy for the bark-beetle without careful trial, it is very probable that its use will 

 be attended with considerable benefit. 



