1882.] 



THE LANCASTER FARMER. 



73 



operation tliey are transplanted ap^ain at a 

 distance of froii) fourteen to twenty inclies, 

 according to tlieir streni;tli. Each trans- 

 plantation rtHiuircs, of course, a new water- 

 ing, which, however, should only he moder- 

 ately ajiplied. The blossoming of the Pyreth- 

 runi coniniLnces the second year, [toward the 

 end of May, and continues to tlic end of 

 September." Mr. Willemot also stales that 

 the plant is very little sensitive to cold, and 

 needs no shelter, even during severe winters. 



The above-quoted directions have reference 

 to the climate of France, and as the cultiva- 

 tion of the plant in many parts of North 

 America is yet an experiment, a great deal of 

 independent judgment must be used. The 

 plants should be treated in the same manner 

 as the ordinary Asters of the garden or other 

 perennial Coniposita^ 



As to the Dalmatian plant, it is well known 

 that Mr. G. N. Nilco, a native of Dalmatia, 

 has of late years successfully cultivated Pi/rc- 

 thrum einerarirpfoliiimxient Stockton, Cal., and 

 the powder from the California-grown plants, 

 to wliieh Mr. Milco has given the name of 

 "Buliach," retains all the insecticide qualities 

 and is far superior to most of the imported 

 powder, as we know from experience. Mr. 

 Milco gives the following advice about plant- 

 ing — advice which applies more particularly 

 to tlie Pacific coast: " Prepare a small bed of 

 fine, loose, sandy, loamy soil, slightly mixed 

 with fine manure. Mix the seed with dry 

 sand and sow carefully on top of the bed. 

 Then with a common rake disturb the surface 

 of the ground half an inch in depth. Sprinkle 

 the bed every evening until sprouted; to much 

 water will cause injury. After it is well 

 sprouted, watering twice a week is sufficient. 

 When about a month old, weed carefully. 

 They should be transplanted to loamy soil 

 during the rainy reason of winter or spring." 



Our own exi)erience with Pyirthntm roaeum 

 as well as Pynthrum cinerariafoliiu in Wash- 

 ington, D. C, has been so far quite satisfac- 

 tory. Some that we planted in the fall of 

 1880 came up quite well in the spring, and a 

 few plants bloomed in November of 1881, 

 though such blooming was doubtless abnormal. 

 The plants from sound seed which we planted 

 this spring are also doing finely, and as the 

 soil is a lather stiff clay and the rains were 

 in early summer many and heavy, we conclude 

 that Mr. Willemot has over stated the deli- 

 cacy of the plants. We have observed further 

 that the seed often lays a long time in the 

 ground before germinating, and that it ger- 

 minates best when not wat red to heavily. 

 We think that the too rapid absorption of 

 moisture often causes the seed to burst pre- 

 maturely and rot. where slower absorption in 

 a soil only tolerably moist affords the best 

 conditions for germination. 



Preparation of the Plants for Use. 



In regard to manufacturing the powder, the 

 tiower-heads should be gathered during fine 

 weatlier, when they are about to open, or at 

 the time when fertilization takes place, as the 

 essential oil that gives the insecticide quali- 

 ties reaches, at this time, its greatest develop- 

 ment. When the blossoming has ceased the 

 stalks may be cut within about four inches 

 from the ground and utilized, being ground 

 and mixed with the flowers in the proportion 



of one-third of their weight. Great care must 

 be taken not to expose the flowers to moisture, 

 or the rays of the sun, or still less to artificial 

 heat. Tliey should be dried under cover, and 

 hermetically closed up in sacks or other ves- 

 sels to prevent untimely pulverization. The 

 finer the flower-heads are pulverized the more 

 effectually the powder acts and the more 

 economical is its use. Proper |iulverization 

 in large quantities is best done by those who 

 make a business of it and have special mill 

 facilities. Lehn & Fink, of New York, have 

 furnislied us with the most satisfactory pow- 

 der. For his own use the farmer can pul- 

 verize smaller (pianties by the simjile method 

 of potmding the flowers in a mortar. It is 

 necessary that the mortar be closed, and a 

 piece of leather through which the pestle 

 moves, such as is generally used in pulverizing 

 pharmaceutic substances in a laboratory, will 

 answer. The (piantity to be pulverized .should 

 not exceed one pound at a time, thus avoid 

 ing too high a degree of heat, which would be 

 injurious to the quality'of the powder. The 

 pulverization being deemed sufficient, the 

 substance is sifted through a silk sieve, and 

 then the remainder, with a new addition of 

 flowers, is put in tlie mortar and pulverized 

 again. 



The best vessels for keeping the powder are 

 fruit jars with patent covers, or any other 

 perfectly tight glass vessel or tin box. 



The Use of Pyrethrum as an'Insecticide 



Up to a comparatively recent period the 

 powder was applied to the destruction of 

 those insects only which are troublesome in 

 dwellings, and Mr. C. AVillemot seems to have 

 been the first in the year 1857, (?) to point 

 out its value against insects injurious to agri- 

 culture and horticulture. He goes, however, 

 too far in his praise of it, and some of his 

 statements as to its efficacy are evidently not 

 based upon actual experiment. Among others 

 he proposes the following remedy: "In order 

 to prevent the ravages of the weevil on wheat 

 fields, the powder is mixed with the grain to 

 be sown, in proportion of about ten ounces to 

 about three bushels, which will save a year's 

 crop." This is simply ridiculous, as every 

 one who is familiar with the properties of 

 Pyrethrum will understand. We have during 

 the past three years largely experimented with 

 it on many species of injurious insects, and 

 fully appreciate its value as a general insecti- 

 cide, which value has been greatly enhanced 

 by the discovery that it can be most econom- 

 ically used m liquid solution; but we are far 

 from considering it a universal remedy for all 

 insects. No such universal remedy exists, 

 and Pyrethrum has its disadvantages as has 

 any other insecticide now in use. The follow- 

 ing are its more serious disadvantages: 1, the 

 action of the powder, in whatever form it 

 may be applied, is not a permanent one in the 

 open air. If e. g., it is applied to a plant, it 

 immediately effects the insects on tliat plant ! 

 with which it comes in contact, but it will 

 prove perfectly harmless to all insects which 

 come on to the plant half an hour (or even 

 less) after the application; 2, the powder acts 

 in the open air— unless, perhaps, applied in 

 very large quantities— only upon actual con- 

 tact with the insect; if c. 3., it is applied to 

 the upper side of a cotton leaf the worms that 



may be on the underside arc not affected by 

 it; 3, it has no eflect on insect eggs, nor on 

 pupa- that are in any way protected or 

 hardened. 



These disadvantages render Pyrethrum in 

 some respects inferior to arsenical poi.sons, but 

 on the other hand, it has tlic one over-siiadow- 

 ing advantage that it is pcu-fectly harmless to 

 plants or to higher animals; and if the culti- 

 vation of the plants in this country should 

 prove a success, and the price of the powder 

 become low enough, the above-mentioned dis- 

 advantages can be overcrmie, to a certain 

 degree, by repealed ai)plicati()ns. 



In a closed room the effect of Pyrethrum 

 on insects is more powerfid than outdoors. 

 Different species of insects are diflerently 

 afleoled by the |)owder. Some resist its action 

 most effectually, e. <j., very hairy caterpillars 

 and especially spiders of all kinds; while 

 others, especially all Ilymenoptera, succumb 

 most readily. In no ca.se are the insects killed 

 instananeously by Pyretlirum. They are ren- 

 dered perfectly helpless a fevv minutes after 

 application, but do not die till some lime after- 

 ward, the period varying from several hours 

 to two or even three days, according to the 

 species. Many insects that have been treated 

 with Pyrethrum show signs of intense pain, 

 while in others the outward symptoms aie 

 much less marked. Differences in tempera- 

 ture and otlier meteorological clianges do not 

 appear to have any influence on the effect of 

 Pyrethrum. 



Modes of Application. 



Pyrethrum can be applied — 1, as dry pow- 

 der; 2, as a fume; 3, as an alcoholic extract 

 diluted ; 4, by simple stirring of the powder 

 in water ; 5, as a ti;a or decoction. 



The following recommendations are bassd 

 on repeated experiments in the field : 



1. Aiqilicntions of PijnthruDi an n dry 

 Po(uc?er.— This method is familiar to n.ost 

 housekeepers, the powder being us d by means 

 of a small pair of bellows. It is then gen- 

 erally used wiihout diluent, but if it is un- 

 adulterated and fresh (which cannot be said, 

 in many instances, of the powder .sold at re- 

 tail by our druggists) it may be considerably 

 diluted with other pulverized mateiial with- 

 out losing its deadly effect, the use of the 

 l>owder thus becoming much cheaper. Of 

 the materials which can be used as diluents, 

 common flour seems to be the best, but finely- 

 sifted wood-ashes, saw-dust from hard wood, 

 etc. — in short, any light and finely-pulverized 

 material which mixes well with the Pyreth- 

 rum powder will answer the purpose. If the 

 mixture is applied inunediately after prejiara- 

 tion, it is always less efficacious than when 

 left in a perfectly tight vessel for about 

 twenty-four hours, or longer, befoie use. 

 This has been proven so far only with the 

 mixture of Pyrethnmi with flour, but holds 

 doubtless true also for oilier diluents. Mr. 

 E. A. Schwarz exiierimented largely under 

 our direction with the mixture of Pyrethrum 

 and flour for the cotton worm, and he found 

 that one part of the powder to 1 1 parts of 

 flour is suflicient to kill the worms (only a 

 portion of the full-grown worms recovering 

 from the eflucts of the powder), if the mixture 

 is applied immediately after preparation ; 

 but if kept in a tight glass jar for about two 



