HANDBOOK OX INSECT ENEMIES OF FLOWERS AXD SHRUBS 63 



Treatment. — Spray with lead arsen- 

 ate. The poisoned-bran mash recom- 

 mended for cutworms (p. 2) may be 

 useful, but its effectiveness has not been 

 demonstrated. 



Solarium Mealybug 



Paper-white narcissus bulbs while in 

 storage may become infested with the 

 solanum mealybug (Phenacoccus solani 

 (Ckll.)). especially in Florida, although 

 the insect also occurs in California. New 

 Mexico. Colorado. Arizona. Utah, and 

 Mississippi. The infestation may be- 

 come so abundant that the bases of the 

 bulbs become covered with cottonlike 

 masses. It is also a serious annoyance, 

 since the storage crates and the wood- 

 work of the storage houses may at times 

 become covered with masses of mealy- 

 buss. This species somewhat resembles 

 those shown in figures 44 and 51, pages 

 28 and 31. It is recorded from a wide 

 range of plants, including ambrosia, 

 aster, malva. nightshade, pansy, pea- 

 nut, potato, tomato, and various weeds 

 and shrubs. Apparently it migrates 

 from these to the roots and bases of 

 narcissus bulbs, and the infestation is 

 brought into storage when the bulbs are 

 harvested. 



Treatment. — After the bulbs have 

 been harvested and dried for at least 

 2 weeks, fumigate them with calcium 

 cyanide, using ^-ounce for every 100 

 cubic feet of space, with an exposure 

 lasting 5 hours. Follow the same pro- 

 cedure as recommended for the tulip 

 aphid (p. 87). Infested crates should 

 also be fumigated to free them of mealy- 



bug- 



; pray the woodwork with a 5- 



percent miscible oil or white-oil emulsion 

 if conditions warrant. 



Caution. — Since calcium cyanide 

 and the gas it produces are deadly 

 poisons, this chemical should be used 

 only by those familiar with the hazards 

 involved. 



Prevention. — Examine all bulbs 

 carefully as they are harvested, and if 

 infested bulbs are found, segregate these 

 from uninfested ones. As soon as the in- 

 fested bulbs have dried sufficiently they 

 should be fumigated. 



Other Pests of Narcissus 



Page 



Red spiders 11 



Flower thrips 74 



Aphids. . 9 



Leafhoppers 10 



NASTURTIUM 



Bean Aphid 



The bean aphid (Aphis fabae Scop. , 

 also known as the dock aphid, i- the 

 plant louse most often found feeding on 

 nasturtium. It is small, slaty blue or 

 black, and is seen in clusters on the 

 under sides of the leaves, on the leaf 

 -terns (fig. 103), and other parts. The 

 continuous feeding causes the leave- to 

 turn yellow and the plants to become 

 dwarfed and otherwise malformed. This 

 aphid is also common on beans and 

 other vegetable crops. In the fall it 

 migrates to dock, euonymus, and pos- 

 sibly other shrubs. The following sea- 

 son it flies back to the summer food 

 plants. 



Figure 103. — Bean aphids feeding on 

 nasturtium stem. About 3 times 



natural >ize. 



The green peach aphid (p. 88) is 

 another plant louse that occasionally 

 feeds on nasturtium. 



Treatment. — Same as for aphids 

 (p. 9). 



Imported Cabbage Worm 



The imported cabbage worm (Picris 

 rapae (L.)), the adult of which i- the 

 white butterfly seen so frequently 

 flying about on summer days, often 

 leaves its preferred food plant and 

 travels to the neighboring flower garden, 

 where it feeds on nasturtium 'fig. 104), 

 mignonette, sweet alyssum, and several 

 other ornamentals. 



The butterfly lays the eggs. The 

 caterpillars, when full-grown, are about 

 an inch in length, with a green velvety 

 body, a pale-yellow stripe down the 

 back, and some yellow spots on each 



