812 



INSECTS 



INULA 



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

 very great. At times hundreds of acres of peas have 

 been 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 

 ]i)0 generations 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 houses, 

 their young being born 

 alive and 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 

 chese are successfully 

 used to kill the aphides 

 in all situations. 



Scale Insects. 

 Since the recent ad- 

 vent of the San Jose" 

 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 rap- 

 idly, the scale Insects 

 are justly to be consid- 

 ered as among the most 

 dangerous and destruc- 

 1162. A spreading board for drying tive of injurious In- 

 soft-winged insects. sects. A single female 

 San Jose" scale may 



rear a brood of from 100 to 600 young, and there may be 

 four or five generations a year; and more than 2,000 

 eggs have been laid by a single Lecanium scale. 



The scale Insects, the dreaded San Jos6 species in- 

 cluded, can be successfully controlled by judicious, in- 

 telligent and timely work with sprays of whale-oil soap, 

 liiiie-sulfur, crude petroleum, or hydrocyanic acid gas, 

 which should be used in the case of nursery stock 



Since 1889 fumigation with hydrocyanic acid gas has 

 been extensively practiced in the citrous orchards of 

 California, 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 nursery 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 coaches, rooms in private houses, 

 and whole flouring mills have been effectively fumigated 

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

 f commercial sulfuric acid, and potassium cyanide 

 98 to 99 per cent pure. The acid is poured into the water 

 in an earthen jar or crock and the cyanide then dropped 

 m. In fumigating trees, rooms or flouring mills, 1 ounce 

 'f the cyanide, 1% fluidounces of sulfuric acid, and 2M 

 ounces of water are used for every 125 cubic feet of 



space ; for nursery stock use the same amounts for eacl 

 100 cubic feet of space ; in greenhouses the gas is use< 

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

 plants. Nursery stock, trees and plants in greenhouse! 

 are usually subjected to the gas for from 30 to (j( 

 minutes ; mills are usually kept closed 12 to 24 hours 

 As potassium cyanide and hydrocyanic acid gas art 

 among the most deadly poisons, fumigation should bt 

 under the direct supervision of competent persons. 



Insects are preserved in collections by securing then: 

 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. 



Insect Literature for Horticulturists. 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, one 

 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 T T ~~ 

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

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

 Entomology." M y SLINGERLAND . 



INUL A (ancient name). Composite. This genus in- 

 cludes some hardy herbaceous plants of the easiest cul- 

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

 orange, each 2-4 in. across, borne in summer. There 

 such a great abundance of autumn-flowering yell, 

 composites in the hardy border that only those Inul^ 

 that bloom in early summer are particularly desirable. 

 Elecampane, I. 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 ' 

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



Inula is a genus of about 56 species, found in Euro r _, 

 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 panicled or corymbose. 

 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. 163. For medic- 

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

 If older they are likely to be stringy and woody. 



ny 

 in 



pe, 



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

 the cleat "d." in Fig. 1162. 



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

 B. Outer involucral 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 

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

 Cult, but not advertised. Earliest blooming Inula in 

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

 has bold but not coarse habit. 



