256 INSECTS AFFECTING VEGETATION 



worms are the principal insects of secondary importance that injure 

 the root and stems of tobacco. Besides the cigarette beetle, only three 

 species are recorded as injuring cured and manufactured tobaccos. 

 These are the rice -weevil, the drug-store beetle and a dermestid 

 beetle. The remedies are the same as for the cigarette beetle. 

 (Year Book Sep. 537 D. of Ag.) 



TESTS OF HOUSE-PLANTS. 



There are but few kinds of house-plants which are not, sooner 

 or later, attacked by insect enemies. Among the most common of 

 these enemies are plant-lice, the so-called red spider, thrips, scale- 

 insects and mealy-bugs. Most housewives are familiar with the 

 small, soft-bodied green or blackish plant-lice which often multiply 

 in great numbers on certain kinds of house-plants. These lice live 

 on the juices of the plants which they suck out by means of their 

 beak-like mouth parts, which they force into the tissues in a simi- 

 lar way that a mosquito bites us. 



The so-called red spider is a minute, spider-like mite, which 

 often swarms over the undersides of the leaves, forming thereon a 

 network of silken threads. Thrips are very small, slender and active 

 little creatures which live 'mostly on the under sides of the leaves, 

 causing yellowish spots where they have fed. 



Several kinds of scale-insects infest house-plants. Some of them 

 are dark brown and the shape of a half-pea when fully grown. The 

 young of these brown scales are lighter colored and flat, closely 

 adhering to the plant from which they suck their food, like the 

 plant-lice. Palms and some other plants are often infested with a 

 smaller, round flat scale about the size of a pin-head. Coleus plants 

 and a few others are often badly infested with small, whitish insects, 

 known as mealy-bugs from their peculiar mealy or cottony appear- 

 ance. They are closely related to the plant-lice and scale-insects, 

 and suck their food from the plants in a similar manner. 



"When good water pressure is available, the simplest and usu- 

 ally an effective method of controlling most insects infesting house- 

 plants is to thoroughly spray the plants with water through a hose 

 and nozzle at frequent intervals. Take the plants outdoors, and 

 by the application of such a spray one can usually knock off most 

 of the insects, excepting the scales. Plant-lice, red spiders, mealy- 

 bugs and thrips will usually succumb to such treatment. When a 

 forceful water spray is not available, a small spray-pump may be 

 substituted and a solution of whale-oil soap (one pound in five or 

 six gallons of water), kerosene emulsion or a strong tobacco decoc- 

 tion may be used as a spray on the plants. It is necessary to aim this 

 spray so as to hit the insects. For scale-insects the housewife must 

 resort to hand work. Take strong soap-suds, or better, the whale- 

 oil soap mentioned above, and with a sponge or rag, sometimes as- 

 sisted by an old tooth-brush, thoroughly wash the infested plants, 

 thus removing the insects. It is necessary to repeat this operation in 

 a week or two to get those that were missed before with their progeny. 

 One should always thoroughly rinse off the plants with water after 



