HANDBOOK OX INSECT ENEMIES OF FLOWERS AND SHRUBS 



GREENHOUSE LEAF TIER 



The greenhouse leaf tier (Phlyctaenia 

 rubigalis (Guen.)) is a good representa- 

 tive of a group of caterpillars that roll, 

 fold, and tie together the leaves and ter- 

 minal growths (fig. 7). It feeds on the 

 inner surface of the folded leaves but 

 may also eat into the buds and flowers. 

 Although chiefly a greenhouse pest, it 

 attacks also many flower-garden plants, 

 including abutilon, ageratum, anemone, 

 aster, canna, carnation, chrysanthemum, 

 dahlia, forget-me-not, geranium, helio- 

 trope, marigold, nasturtium, pansy, 

 peony, rose, salvia, sweet pea, violet, 

 and wallflower. When full-grown the 

 yellowish-green caterpillars (fig. 7) are 

 about % inch long. The adult is a small 

 tan-colored moth. 



Figure 7. — Terminal leaves of aster 

 folded and tied together by the green- 

 house leaf tier. Inset, full-grown cater- 

 pillar, 1% times natural size. 



Other species with similar habits, but 

 discussed elsewhere, are listed in the in- 

 dex under ''leaf tiers" and "leaf rollers." 

 Similar remedies can be used for these 

 related species. 



Treatment. — Where only a few 

 plants are infested the affected parts 

 can be pinched off and destroyed. 

 This often prevents an infestation from 

 becoming serious. If a heavy infesta- 

 tion exists, dust the plants with a mix- 

 ture consisting of equal parts of tobacco 

 dust and pyrethrum powder (contain- 

 ing about 6.9 to 1.3 percent of pyre- 

 thrins). Make two successive appli- 

 cations, separated by an interval of 



l /i hour. The first one drive- the eater- 

 pi liar-; from their place of concealment, 

 and the second one kills them. Another 

 remedy is to spray with a combination 

 of derris and pyrethrum prepared as 

 given on page 99, or a commercial prep- 

 aration of pyrethrum and rotenone. 

 Make two applications 30 minutes 

 apart. Spraying or dusting with lead 

 arsenate when the infestation first 

 starts is another means of control. 



POISONOUS CATERPILLARS 



Although most caterpillars are not 

 poisonous, those of several species have 

 bodies provided with stiff hairs or spines 

 that are somewhat poisonous. These 

 spines may inflict a painful burning 

 sensation when they come in contact 

 with tender skin. Only certain hairs 

 of the body are poisonous. These 

 caterpillars occasionally feed on and 

 injure certain garden plants, shrub-, 

 and trees. The more common species 

 are discussed in the paragraphs that 

 follow. 



Stinging Rose Caterpillar 



The stinging rose caterpillar (Parasa 

 indetermina (Bvdl.)) is sluglike and feeds 

 on rose leaves from the under side. It 

 also attacks various low-growing bushes 

 and trees, as dogwood, chestnut, oak, 

 wild cherry, hickory, pawpaw, bayberry, 

 plum, apple, and pear. It usually be- 

 comes full-grown in September, and 

 overwinters in a dark-colored cocoon 

 among leaves and other refuse on the 

 ground. The mature caterpillar is 

 about % inch long. It is rather strik- 

 ingly marked (fig. 8) with red, white, 

 and violet stripes and seven pairs of 

 large spine-bearing processes. The 

 adult, a pale cinnamon-brown moth 

 with wings branded with green and 

 brown, appears and lays its eggs in 

 Julv. 



Figure 8. — Stinging rose caterpillar. 

 About natural size. 



