42 



MISC. PUBLICATION 62 6, U. S. DEPT. OF AGRICULTURE 



ently overwinters as a full-grown scale. 

 In the Central Atlantic States there are 

 three generations, the young of the first 

 usually hatching about the middle of 

 May, the second about the latter part 

 of June, and the third in August. 



Treatment. — Apply a dormant- 

 strength oil spray just before growth 

 starts in the spring. Before spraying, 

 remove and burn all heavily infested 

 parts that can be spared. When the 

 young are hatching, as indicated above, 

 spray with a combination of white-oil 

 emulsion and nicotine sulfate (p. 101), 

 or make several applications of a nico- 

 tine sulfate and soap solution. 



Other Pests of Euonymus 



Page 



Bean aphid 63 



San Jose scale 57 



Cottony maple scale 47 



Lilac leaf miner 58 



FERNS 



Florida Fern Caterpillar 



In the Southern States a cutworm 

 known as the Florida fern caterpillar 

 (Callopistria floridensis (Guen.)) often 

 becomes a serious menace, especially 

 in the larger ferneries. The caterpillar 

 feeds on the foliage and disfigures the 

 plants. Two color phases of the cater- 

 pillars (fig. 68) are present when full- 





Figure 68. — Florida fern caterpillar. 

 About natural size. 



grown, one a pale green and the other a 

 velvety black. At this stage they are 

 nearly \ x /% inches long. Various other 

 caterpillars, including cutworms (p. 

 2) and army worms (p. 2), also feed 

 on and injure ferns. 



Treatment. — Same control as for 

 cutworms (p. 2). Pyrethrum, used 

 either as a spray or a dust, is also ef- 

 fective against the young caterpillars. 



Two-Spotted Spider Mite 



The two-spotted spider mite ( Tetran- 

 ychus bimaculatus Harv.) infests the 

 fern asparagus in Florida and can cause 

 severe injury. These mites feed in the 

 new shoots and cause them to turn 

 brown and become stunted. The foliage 

 of the Boston type of ferns is also sub- 

 ject to attack by this pest, which causes 

 the leaves gradually to turn brown and 

 die. 



Treatment. — Spraying several times 

 with the combination of derris and 

 sulfonated castor oil (p. 99), repeating 

 the application at intervals of a week, 

 is recommended. Frequent syringing 

 with water is helpful. 



Prevention. — Keep down all weeds 

 in and around fern plantings. 



Hemispherical Scale 



Several scale insects attack both 

 indoor and garden ferns, and of these 

 the hemispherical scale (Saissetia hemi- 

 sphaerica (Targ.)) is most often en- 

 countered. Like other scale insects, 

 this species feeds by sucking the plant 

 juices. This causes a weakening of 

 the portions that are attacked. The 

 large amount of honeydew which it 

 excretes forms an ideal medium for the 

 growth of sooty fungus. The blacken- 

 ing of the fronds ruins the ornamental 

 value of ferns. In addition, ants and 

 other insects are attracted by the 

 honeydew. This scale insect is similar 

 in size, color, and shape to the soft 

 scale (p. 43), except that it is more 

 swollen so that it has a hemispherical 

 appearance (fig. 69). It varies from a 



Figure 69. — Hemispherical scale on a 

 palm stem. Three times natural size. 



