12 MISC. PUBLICATION 6 2 6, U. S. DEPT. OF AGRICULTURE 



Figure 21. — Webbing spun by the two- 

 spotted spider mite on a" chrysan- 

 themum plant. 



crowns of various perennials and weeds, 

 and attacks the new growth as soon as 

 it starts in the spring. Certain other 

 species hibernate in the egg stage on the 

 bark and under the bud scales of various 

 trees and shrubs which they infest. 



Treatment. — Spraying with a com- 

 bination of derris and sulfonated castor 

 oil (p. 99) is very effective. The 

 thiocyanate sprays are also satisfactory, 

 but they should be followed by syring- 

 ing with water an hour or two after 

 application to avoid injury, especially 

 on young and tender plants. White-oil 

 emulsions used as directed by the 

 manufacturer will give good control and 

 may be used on the hardier plants. 

 Dusting with dusting sulfur is effective 

 during the summer, but in extremely 

 hot weather it may burn the leaves of 

 tender plants. Several applications of 

 the insecticide selected are usually 

 necessary and should be made with an 

 interval of a week or 10 days between 

 treatments. Frequent syringing or 

 washing with a stream of water applied 

 with force from several angles is of 

 considerable value but should not be 

 depended on for complete control. 



Prevention. — Cleaning up the gar- 

 den is the first step to be practiced, 

 including the gathering of all litter, old 

 leaves, weeds, and dead, dying, or 

 heavily infested plants, and burning 

 them. This is especially true for the 

 common red spider, which overwinters 



in the litter and in the crowns and buds 

 of various host plants. Much damage 

 can be prevented if such clean-up meas- 

 ures are carried out and if treatments 

 are started early in the spring on the 

 first evidence of red spider injury. 



Glues are recommended by~ some 

 authorities as a safe spray for use on 

 most plants, particularly evergreens 

 which are subject to injury where dor- 

 mant oils or sulfur sprays are applied. 

 A spray may be prepared by dissolving 

 1 pound of cabinetmaker's glue in 10 

 gallons of water. 



ANTS 



Ants are frequently annoying and 

 occasionally injurious in flower gardens. 

 Sometimes they damage plants by 

 nesting among the roots and exposing 

 them to drying. Some ants may also 

 steal newly planted seeds. Sometimes 

 they are injurious through colonizing 

 and protecting aphids, mealybugs, and 

 certain scale insects. Often, however, 

 they are merely annoying, being at- 

 tracted to plants by the presence of 

 aphids or other sucking insects which are 

 excreting quantities of honeydew, a 

 liquid much sought after by ants and 

 other insects as food. Ants are also 

 attracted by souring sap from tree and 

 plant wounds, and by sweet secretions 

 of certain parts of plants, such as the 

 flower buds of peonies. 



Treatment and prevention. — 

 When honeydew is responsible for the 

 presence of ants, the insects supplying 

 this material should be combated. 

 Spraying the infested portions with a 

 nicotine sulfate and soap solution or a 

 strong pyrethrum spray is of consider- 

 able value. Where wounds or hollows 

 are the attraction the infested plants 

 should be destroyed, or in the case of 

 woody shrubs the wounds should be 

 cleaned and protected by a thin 

 coating of shellac, white-lead paint, or 

 grafting wax. 



Ants are difficult to control, and no 

 entirely satisfactory remedy is avail- 

 able that will serve under all conditions 

 and for all species. Several methods of 

 control are therefore suggested. Per- 

 manent control depends upon locating 

 the nest and destroying the colony 

 therein, especially the reproductive 

 forms and the young. These forms are 

 located deeply within the nest, and if 

 they are not killed the trouble will 

 occur again. When the nests are in the 

 soil of the lawn or garden, the individual 

 anthills or infested area should be 

 treated with carbon disulfide, according 



