No. 6. DEPARTMENT OF AGRICULTURE. 549 



For all kiuds of insects on plants above ground, use the paper tents 

 described as "Mechanical Device No. 2," and put under each about a 

 teaspoouful of carbide, either on damp soil or in water, and leave it 

 for an hour. \'egetation is not injured. 



12. Tobacco. This is a good insecticide for certain species when 

 used either as a fine dust or in a decoction. It will not injure the 

 plants, and will act as a valuable fertilizer. It should come into 

 contact with insects above ground, as thej' will not eat it. 



For insects feeding beneath the surface of the soil nothing is better 

 than tobacco stems or dust placed around the plant and stirred into 

 the soil. Thej' do not eat it, but can not avoid coming into contact 

 with it. The stems can be procured at little or no cost from cigar fac- 

 tories. Stems are as useful as any part of the tobacco plant in 

 making a tea or decoction. This should be applied as a spray. 



13. Sulphur. This is often applied as a powder, but is too expen- 

 sive for general application on a large scale. It is not necessary to 

 use the pure "flower of sulphur, or powder form, but it may be mixed 

 with several times its bulk of some kind of dust, as directed for Paris 

 green, although the proportion of the dilutant must be only about 

 one-third as great. 



14. Land Plaster. This is recommended more as a repellaut than 

 as a remedy. It is also a fertilizer. It is applied by sprinkling it on 

 the plants or sowing it broadcast over the field. When it is sown with 

 the wind it drives certain species of insects to plants and weeds to the 

 leeward. It is more eti'ective as a repellant if some turpentine or 

 kerosene be mixed with it. 



15. Air-slaked Lime. This is used as in Land Plaster (No. 14), and 

 is even more effective. The Cucumber Beetle, especially, is driven be- 

 fore it, and can be kept away from the plants by its frequent use. Of 

 course, a repellant only drives insects away, and does not kill them. 



This means that they become more abundant upon the plants to 

 which they are thus driven, but it sometimes a good plan to drive 

 them to one side of the field and there spray with some killing insec- 

 ticide, according to that recommended for the species in question. 



OTHER INVERTEBRATE ANIMALS INJURING CUCURBITA- 



CEOUS PLANTS. 



Besides the insects discussed in the preceding text, we have found 

 two species of slugs (Limax), two of Centipedes and one of Millipede, 

 iLJuring the fruits of cucurbitaceous plants by eating into them. 



