HANDBOOK ON INSECT ENEMIES OF FLOWERS AND SHRUBS 65 



Treatment. — Drench the soil sur- 

 rounding the plant with a solution 

 consisting of 2 , i> teaspoonfuls (12 cc.) of 

 dichloroethyl ether in 1 gallon of water. 

 Usually 1 gallon of the solution is 

 enough to treat a large palm plant. 



Prevention. — Examine all plants 

 when they are repotted and see that 

 they are free of mealybugs. 



Scale Insects 



Several scale insects attack palms 

 that are grown out of doors. These are 

 tiny sucking insects, many no larger 

 than a pinhead, that appear like small, 

 flattened, waxy scales (fig. 107) attached 

 to the leaves, stems, and trunk. Some 

 species are narrow (fig. 108), whereas 

 others are slightly larger and hemis- 

 pherical (fig. 69). The color may be 

 brown, dirty white, or purplish. When 

 extremely numerous, they encrust the 

 surface of the leaves and stems and 

 seriously weaken the plants. 



Figure 107. — Coconut scale (Aspidiotus 

 destructor Sign.) encrusting a leaf of 

 cycas palm. About 3 times natural 



Treatment. — Where only one or two 

 small plants are infested these may be 

 scrubbed with a nicotine sulfate and 

 soap solution (p. 97) and a soft brush or 

 sponge. Larger plants may be sprayed 

 with a white-oil emulsion or a thiocy- 

 anate spray diluted according to the 

 manufacturer's instructions. Following 

 any of these treatments, the plants 

 should be rinsed with clear water an 

 hour or two later. 



Other Pests of Palm 



Page 

 Mealybugs 31 



Greenhouse orthezia ., 32 



Figure 108. — Portion of palm leaf in- 

 fested with the black thread scale 

 (Ischnaspis longirostris (Sign.)). About 

 3 times natural size. 



PANSY 



Violet Sawfly 



The leaves of pansies and violets, 

 especially in the eastern part of the 

 United States and Canada, are fre- 

 quently fed upon by the larvae, or 

 false caterpillars, of the violet saw- 

 fly (Ametastegia pallipes (Spin.)) (fig. 

 109). An examination of the lower 

 leaves of the plants often reveals some 

 bluish-black, smooth larvae, about half 

 an inch long, conspicuously marked with 

 white spots on the back and sides. In 

 the earlier stages the larvae feed on and 

 skeletonize the lower surface of the 

 leaves and then eat holes in them, 

 usually feeding at night. Later they may 

 eat along the leaf edges and then com- 

 pletely defoliate the plants. Feeding 

 usuallv becomes most evident late in 



