812 



INSECTS 



INULA 



In the aggregate, the damage done by plant-lice is 

 very great. At times hundreds of acres of peas have 

 heen ruined by an aphid. Nursery stock often suffers 

 severely, but bearing fruit trees are not often seriously 

 injured by them. About 40 different kinds of aphides 

 live in greenhouses, where a perpetual warfare has to 

 be waged against them. In 4 years we have reared nearly 

 100 generatious of a common aphis in greenhouses, 



and there were no in- 

 dications of any egg- 

 stage or of male forms 

 during this time, so that 

 they may thus breed 

 indefinitely in bouses, 

 their y()ung being born 

 alive anil no males ap- 

 pearing. 



The standard reme- 

 dies for plant-lice are 

 whale-oil soap, kero- 

 sene emulsion, kero- 

 water, and tobacco in 

 various ways (as a de- 

 coction, dry as a dust, 

 or the "Roseleaf" or 

 similar extracts), and 

 these are successfully 

 used to kill the aphides 

 in all situations. 



S c ale 1 }t s f c f s.— 

 Since the recent ad- 

 vent of the San Jos^ 

 scale into the eastern 

 United States, scale In- 

 sects of all kinds have 

 attracted world - wide 

 attention. They are all 

 small Insects, and de- 

 rive their name from 

 the fact that their ten- 

 der bodies are protect- 

 ed by hard, scale-like 

 coverings secreted by 

 the Insects. Thus pro- 

 tected, they are difficult 

 Insects to kill, and as 

 they are easily trans- 

 ported on nursery 

 stock, buds or cions, 

 and also multiply raji- 

 idly, the scale Inserts 

 are justly to be consid- 

 ered as among the most 

 dangerous aTid destrnr- 

 tive of injurious In- 

 sects. A single female 

 San Jose scale may 

 rear a brood of from 100 to GOO young, and there may be 

 four or five generations a year; and more than 2,00(i 

 eggs have been laid by a single Lecanium scale. 



The scale Insects, the dreaded San Jose species in- 

 cluded, can be successfully controlled by judicious, in- 

 telligent and timely work with sprays of whale-oil soaii. 

 kerowater, crude petroleum, or hydrocyanic acid gas, 

 which shouhl be used in the case of nursery stock. 



Since 188!* fumigation with hydrocyanic acid gas has 

 been extensively practiced in the citrous orchards of 

 (Jalifornia, and now Florida and South African fruit- 

 growers are also using it in their orchards. Large gas- 

 tight tents or boxes are placed over the trees and the 

 gas then generated within. Much niirsei'y stock is now 

 treated with the gas in tight boxes or houses ; this is 

 required by law in Maryland and the province of Ontario, 

 and it should be practiced in other regions. Recently 

 greenhouses, railway coa(dies, rooms in private houses, 

 and whole flouring mills have been eifectively fumigated 

 with this gas. It is generated with water, a good grjide 

 of commercial sulfuric acid, and potassium cyanide 

 98 to 90 per cent pure. The acid is poured into the water 

 in an earthen jar or crock and the cyanide then dropi>ed 

 in. In fumigating trees, rooms or flouring mills, I ounee 

 of the cyanide, 1% fluidounces of sulfuric acid, and 2H 

 ounces of water are used for everv 125 cul)ic feet of 



1 162. A spreading board for drying 

 soft-winged insects. 



space ; for nursery stock use the same amounts for each 

 100 cubic feet of space ; in greenhouses the gas is used 

 about one-half as strong, or even less for some kinds of 

 plants. Nursery stock, trees and plants in greenhouses 

 are usually subjected to the gas for from 30 to 60 

 minutes ; mills are usually kept closed 12 to 24 hours. 

 As potassium cyanide and hydrocyanic acid gas are 

 among the most deadly poisons, fumigation should be 

 under the direct supervision of competent persons. 



Insects are preserved in collections by securing them 

 in tight cases by means of a pin inserted through the 

 thorax, or through the right wing if the subject is a 

 beetle. Moths and butterflies are pinned in position on 

 a spreading-board until thoroughly dried. .See Figs. 

 1159-1163. Every horticulturist should make a collec- 

 tion of injurious Insects. 



I H. sect Litcrutiire for Sorticnif wrists . —Horticultur- 

 ists should keep in close touch with the experiment sta- 

 tions and state entomologists of their own and of other 

 states, and also with the Department of Agriculture at 

 Washington; for it is from these sources that the best 

 and latest advice regarding injurious Insects is now be- 

 ing disseminated free, either by personal correspon- 

 dence or by means of bulletins. Among the books, onp 

 or more of which may well find a place in a horticul- 

 turist's library are the following : Weed's "Insects and 

 Insecticides," Sempers' "Injurious Insects and the Use 

 of Insecticides," Lodeman's "The Spraying of Plants," 

 Saunders' "Fruit Insects," and Smith's "Economic 

 Entomology." m. V. Slingerland. 



Inula (ancient namej. Composite. This genus in- 

 cludes some hardy herbaceous plants of the easiest cul- 

 ture and of rather coarse habit, with heads of yellow or 

 orange, each 2—4 in. across, borne in summer. There is 

 such a great abundance of autumn-flowering yellow 

 composites in the hardy border that only those Inulas 

 that bloom in early summer are particularly desirable. 

 Elecampane, /. Helenium, is probably also cultivated 

 for medicine. A preparation of the mucilaginous roots 

 is common in drug stores. Inula flowers have as many 

 as 40 linear rays. The plants like a sunny position in 

 any garden soil, and are prop, by division or seed. 



inula is a genus of about 56 species, found in Europe, 

 Asia and Africa: herbs, usually perennial, glandular, 

 hairy: Ivs. radical or alternate, entire or serrate: heads 

 large, medium or small, solitary, corymbose, panicled or 

 crowded at the crown: rays yellow, rarely white. 



A. Stems pnvirJed or corijnihose. 

 Helenium, Linn. Elecampane. Fig. 1164. Tall, 

 thick-stemmed : Ivs. unequally dentate-serrate : root- 

 Ivs. elliptic-oblong, narrowed into a petiole; stem-lvs. 

 half -clasping, cordate-oblong: outer involucral parts 

 leafy, ovate. Wet, sandy and mountainous regions. 

 Eu., N.Asia. Naturalized in Amer. D. 1G3. — For medic- 

 inal purposes, 2-year-old roots should be dug in August. 

 If older they are likely to be stringy and woody. 



1163. A cross-section of spreading board in front of 

 the cleat "d." in Fie- 1162. 



AA. Stems 1-fld., or with at most 2 or 3 heads. 

 B. Oitfer invoJucral parts linear and numerous. 

 grandifldra, Willd, Height 2-3 ft.: Ivs. elliptic-ob- 

 long, serrulate, all sessile; upper ones subcordate; 

 lower ones 2-4 in. long: glands numerous: heads 

 3^4-4 in. across. Himalayas, Caucasus. G.F. 6:406.— 

 Cult, but not advertised." Earliest blooming Inula iu 

 cult. Bears orange-yellow fls. 5 in. across in June, and 

 has bold but not coarse habit. 



