ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



31 



or rolled down over the twine (fig. 38), forming a sort of inverted funnel 

 in which the worms are caught. On rough or uneven trunks it may 

 be necessary to fill in depressions under the bands with extra cotton 

 or to put a thin band of some sticky substance on the tree before the 

 cotton band is applied, to prevent the worms from crawling under it. 



Bands of sticky material (fig. 39) or of axle grease are often used. 

 They should be 3 or 4 inches wide, and are effective only as long 

 as they remain sticky. 

 Dust blown by the 

 wind or from cultivat- 

 ing operations often 

 covers these bands and 

 makes them useless. 

 They should not be put 

 on young or smooth- 

 barked trees, as they 

 roughen and may kill 

 the bark. 



Baits are very gen- 

 erally used to control 

 cutworms in gardens 

 and fields, and are 

 of some value against 

 climbing cutworms, 

 especially in moist cli- 

 mates. They are less 

 valuable in arid regions, where they dry out too rapidly. A suitable 

 bait may be made of the following materials: 



Wheat bran or shorts 25 pounds. 



Paris green or powdered white arsenic or 



sodium fluoride or sodium fluosilicate 1 pound. 



Water Enough to moisten. 



A small handful of the bait placed at the base of each tree is suffi- 

 cient. The bait is attractive only while it is moist, and a light covering 

 of grass or hay will keep it in this condition longer. Half of the 

 water used may be replaced by glycerin to prevent rapid drying of 

 the bait. Young children, livestock, poultry, or birds should not be 

 allowed to get at the bait, as it is very poisonous. Vessels used for 

 mixing it should be cleaned thoroughly before the bait dries, as they 

 are difficult to clean afterwards. 



Figure 34.— Young pears injured by tarnished plant bug. 



GREEN FRUIT WORMS 



Related to the cutworms are the green fruit worms (Graptolitha 

 spp.). When young these worms feed on buds and leaves and are 

 not often noticed, but when about half grown they begin feeding on 

 the fruit (fig. 40). They are then smooth green worms, an inch 

 or so long, which eat large holes in the developing apples or pears. 

 They are most often seen during May and June. The fruit that is 

 attacked may drop off, or if the cavities are shallow they heal over 

 and result in russeted scars. When the worms are full grown they 

 make cells in the ground, where they transform to brown pupae in a 

 manner similar to that of the cutworms. The moths emerge late in 

 the faU or early in the spring and lay eggs singly on the trees. Con- 

 trol measures are not often needed, as the sprays applied for the codling 



