PROTECTING PLANTS 205 



Pear insects. — The psylla is one of the most serious insects affecting 

 the pear tree. It is a minute, yellowish, flat-bodied, sucking insect 

 often found in the axils of the leaves and fruit early in the season. They 

 develop into minute cicada-like jumping-lice. The young psyllas 

 secrete a large quantity of honey-dew in which a peculiar black fungus 

 grows, giving the bark a characteristic sooty appearance. There may 

 be four broods annually and the trees are often seriously injured. 

 After the blossoms fall, spray with kerosene emulsion, diluted with 6 

 parts of water, or whale-oil soap, 1 lb. in 4 or 5 gal. of water. Repeat 

 the application at intervals of 3 to 7 days until the insects are under 

 control. Tobacco extracts may be tried. 



The pear slug is a small, slimy, dark green larva which skeletonizes 

 the leaves in June, and a second brood appears in August. Spray 

 thoroughly with 1 lb. Paris green, or 4 lb. arsenate of lead, in ] 00 gal. 

 of water. 



Potato insects. — The Colorado potato beetle, or potato-bug, emerges 

 from hibernation in the spring and lays masses of orange eggs on the 

 under side of the leaves. The larvae are known as "slugs" and "soft- 

 shells " and cause most of the injury to the vines. Spray with Paris 

 green, 2 lb. in 100 gal. of water, or arsenite of soda combined with 

 bordeaux mixture. It may sometimes be necessaiy to use a greater 

 strength of the poison, particularly on the older "slugs." 



The small black flea-beetles riddle the leaves with holes and cause 

 the foliage to die. Bordeaux mixture as applied for potato blight 

 protects the plants by making them repellent to the beetles. 



Raspberry, blackberry, and dewberry insects. — The greenish, spiny 

 larvaj of the saw-fly feed on the tender leaves in spring. Spray with 

 Paris green or arsenate of lead, or apply hellebore. 



The cane-borer is a grub that burrows down through the canes, 

 causing them to die. In laying her eggs, the adult beetle girdles the 

 tip of the cane with a ring of punctures, causing it to wither and droop. 

 In midsummer, cut off and destroy the drooping tips. 



Red spider. — Minute reddish mites on the under sides of leaves in 

 greenhouses and sometimes out of doors in dry weather. Syringe off 

 the plants with clear water two or three times a week, taking care not 

 to drench the beds. Red spider and black mite may be treated with 

 sulfocide. 



Rose Insects. — The green plant-lice usually work on the buds, and 



