handbook ox insect enemies of flowers and shrubs 21 



it so frequently attacks and destroys 

 aster. It also attacks calendula, clem- 

 atis, chrysanthemum, dahlia, dianthus, 

 gladiolus, phlox, and zinnia. This 

 beetle (fig. 14. p. 7) is about half an 

 inch long and is uniformly black. It is 

 a voracious feeder and usually occurs 

 in large numbers. 



Treatment and prevention. — See 

 Blister Beetles, page 7. 



Root Aphids 



Certain species of aphids, especially 

 the corn root aphid (Anur aphis maidi- 

 radicis (Forbes)), attack the roots of 

 asters and a number of other plants, 

 including browallia, calendula, primrose, 

 and sweet pea, and frequently cause 

 extensive damage to those infested. 

 When asters are heavily attacked little 

 or no growth is made, and the leaves 

 turn yellow and wilt in the bright sun. 

 Upon examining the roots, small, bluish- 

 green aphids are usually found. These 

 pests are fostered by several species of 

 garden ants, which place the aphids 

 upon stems of desirable plants and care 

 for the eggs during the winter, later 

 transferring the young plant lice to the 

 roots along which the ants have made 

 their burrows. 



Treatment. — Root aphids are diffi- 

 cult to control on growing vegetation, 

 and no entirely satisfactory remedy is 

 known. Usually the elimination of ants 

 (p. 12) will do much toward reducing an 

 infestation. 



Where growing plants are infested, 

 one of the following measures will 

 usually be of value. A nicotine sulfate 

 solution, containing 2 teaspoonfuls to 

 each gallon of water, without soap, can 

 be applied by pulling back some of the 

 soil at the base of the plant and pouring 

 from 1 cupful to a pint or more, depend- 

 ing on the size of the plant, into this 

 depression, after which the soil is pushed 

 back into place. Fresh tobacco or 

 nicotine dust mixed with equal parts of 

 air-slaked lime can be worked in around 

 the roots of infested plants. 



Where it is necessary to plant in 

 ground previously infested, the soil may 

 in some cases be treated by applying a 

 heavy coating of equal parts of tobacco 

 dust and air-slaked lime over the entire 

 area and then spading this in, permitting 

 rains to leach the material through the 

 soil before planting; or the carbon di- 

 sulfide treatment (p. — ) can be used, 

 and may be applied only a few days 

 prior to planting. These treatments 

 are more effective when soil tempera- 

 tures are fairly high. 



Prevention. — Where a planting of 

 aster or other susceptible plant- has 

 been infested, it is advisable to rotate 

 these crops, using the ground the follow- 

 ing year for plants not closely related. 

 Thorough spading in the fall will dis- 

 turb the ant nests, where the aphid eggs 

 are found, and will destroy many of 

 these eggs by exposure. 



Asiasfic Garden Beetle 



The Asiatic garden beetle (Autoserica 

 castanea (Arrow)), which is of oriental 

 origin, has in recent years become a pest 

 of flowering and ornamental plants in 

 several localities in the Eastern States. 

 It is often found along with the Japanese 

 beetle. The beetle (fig. 34) is less than 

 half an inch long, is dull chestnut brown, 

 and looks somewhat like a coffee bean. 

 It feeds on the leaves, buds, and flowers 

 of a>ter, barberry, chrvsanthemum, 

 dahlia, rose, strawflower, sunflower, 

 viburnum, and many other plants. In 

 some cases 50 to 100 percent of the 

 blossoms are ruined. The foliage on 

 which the beetle feeds becomes ragged, 

 and in a case of heavy feeding only the 

 midribs are left. Unlike the Japanese 

 beetle, which is active in the daytime, 

 the adults hide in the soil during the 

 day but appear at dusk and feed only 

 at night. The beetles are attracted to 

 electric lights, and often they become 

 so numerous in brightly lighted places 

 that they annoy persons by flying about 

 and alighting on them. The larvae feed 

 on the roots of plants and at times 

 destroy many ornamental and vegetable 

 garden plants. 



FiGUBB 34. — The Asiatic garden beetle. 

 About 3 times natural size. 



