152 HORTICULTURAL MANUAL. 



gas in tight boxes or houses since the advent of the San 

 Jose scale east of the Rocky Mountains. 



161. Some Miscellaneous Insects. The amateur and 

 beginner in fruit-growing and home-making should keep 

 in mind the fact that about all our injurious insects may 

 be divided into two general classes. (1) Those that have 

 jaws for eating, such as the strawberry- worm, canker- 

 worm, curculio, caterpillars, and beetles can be destroyed 

 by spraying with poisons. (2) The scale insects, plant 

 lice, true bugs, mosquitoes, and all insects with mouths 

 fitted for sucking their food from the inner tissue of leaf, 

 bud, or young wood must be destroyed by some applica- 

 tion such as kerosene applied on their bodies or by some 

 deadly gas. Kerosene in emulsion of soap has become a 

 leading remedy, as it is about the only spray that will 

 penetrate the scale, and it paralyzes the young insects as 

 soon as it touches them. 



In some cases it is not advisable to use poisons to 

 destroy the gnawing insects. As an instance, the cabbage- 

 worm cannot be attacked by poisons when the worm is 

 most active. So gardeners use very hot water to destroy 

 the worms and others use a repellent that the butterflies 

 will avoid, such as water that has stood on coal tar until 

 well scented. As the worms are slimy, others dust the 

 worms with wheat flour that kills them by closing their 

 pores. Hellebore powder is also used, as it kills the worms 

 and is said to lose its strength when exposed to the air. 



The currant and gooseberry worm is destroyed by large 

 growers by spraying with weak arsenite of lime when the 

 leaves are beginning to expand and when the leaves are 

 about fully grown. But the amateur is apt to wait until 

 the fruit is half grown. In this case hellebore in powder, 

 or mixed with water, can be used as above stated. If the 



