218 THE PRINCIPLES OF FLORICULTURE 



Euxoa, Feltia, and Noctua are most common. Cutworms vary 

 considerably in the details of their life history, but in general, 

 there is a similarity among the different genera and species. The 

 dull brown moths are night flying, and lay their eggs at the base 

 of the plants. They hatch into dull-colored caterpillars, vary- 

 ing in length from one to two inches. As a rule, they feed on 

 succulent vegetable tissue near the ground, but if this is not 

 available, some species will climb the stem, and feed on devel- 

 oping buds or tender foliage. Under glass, cutworms are some- 

 times' destructive to carnations. They feed on the side of the 

 bud, often making a large opening. 



249. Remedial measures. By carefully inspecting the 

 plants after dark with a light, many of the worms may be dis- 

 covered and destroyed. Since they spend the day in the soil 

 just below the surface, careful watch for them should always be 

 kept when stirring the soil in plant beds. Cutworms are not 

 active, and they will eat attractive food which is on the ground 

 rather than climb plant stems for it. A poisoned bait is, there- 

 fore, an excellent method of exterminating them. An ounce 

 of Paris green or white arsenic may be mixed with a pound of 

 bran, adding enough water to make a soft mash, and also suf- 

 ficient molasses to attract the pests. Snails and slugs may also 

 be trapped in a similar manner. 



Cutworms pass the winter in cells which they make for them- 

 selves in the soil. If these cells are disturbed by fall plowing, 

 many cutworms will be destroyed. The plowing should, how- 

 ever, be done late enough so that the worms cannot crawl back 

 into the soil before they are killed by the cold. 



250. Pests exterminated by water sprays and salt solutions. 

 The red-spider. Red-spiders attack a wide range of green- 

 house plants. They are nearly microscopic in size, and vary 

 in color from green and yellow when immature, to the bright red 

 of the adult. When mature, the red-spider spins a fine web 

 over the foliage, and under this protection, feeds on the epider- 

 mis of the leaf. Here also the eggs are laid, and the young are 

 reared. The presence of red-spiders is indicated by a yellowing 

 of the foliage. An experienced eye rarely mistakes the attacks. 



251. Greenhouse conditions which favor growth and repro- 

 duction. Hot, dry atmospheric conditions in the houses 

 favor development of the red-spider so that when plants are 

 first placed in the houses, care should be taken to syringe them 

 frequently and to moisten the walks to keep the pests from gain- 

 ing a foothold. Once established, they are difficult to exter- 

 minate, and even a damp atmosphere has little effect on them. x 



