THE AGEICULTUKAL NEWS. 



March 9. I»l8. 



INSECT NOTES, 



QUASSIA EXTRACT AS A CONTACT 



INSECTICIDE. 



An article under the above titU^ appeared in ihe/oi/r/Ki/ 

 *>/ Ai:rit! Ituri'.l A\suin/.' tor September 3, 1917 (A'ol. X, No. 

 10) describing some experiments undertaken to find out the 

 value of quai;.-ia extract a> a general insecticide lor all aphids, 

 since this extract ha.* been reported in literature as efficient 

 against the hop aphis (J'/h>/vi/i>;/ iiKiniili, Schr.). Tlie results 

 of these experiments by Messrs. N. E. Mclndoo and A. F. 

 Sievers may be of interest, and are given in the following 

 notes. 



Official quas.-iais derived from tiXktx Atsdii-ion {Picms- 

 viu) c.xahd. bwz. (family Siniarubaceae), known commercially 

 as Jamaica quassia, or from Qxcsna amira, L., a plant of 

 I lie same familx. kiioun commercially as .Surinam quassia. 

 Accorditg to the literature on this subject there are several 

 c her plants w ^ich furnish wood with similar characteristics 

 whose active constituent is identical with, or similar to 

 quassiin, the bitter principle and main constituent of official 

 quassia. These include Si)iuiri!l<a mnara, Aubl., S. vcysicolor, 

 St. Hil., .Uschrioii (I'nrnswa) i/i/assioides, Kenn., and 

 Ailaatliiis e.xcclsa, lloxb. 



The authors give a historical review of the literature 

 dealing with quassia and quaesiin, from which it seems 

 that quassia has been used in different countries as a remedy 

 for various internal disorders of man, and that from time to 

 tin e numerous experiments have been made to find out thr 

 best way to extract quassia, aE<l to determine its different 

 constituents. 



The literature on the use of c]ua.ssia extract as an 

 insecticide is also reviewed, from which it appears that 

 cj'- isiaext-act used in a spray .solution with .soap is efifective 

 against the hop aphis, but its action is slow. 



The authors used a number of aphids and other insects 

 in their experiments to determine the effectiveness of quassia 

 extract as an insecticiile. They tested the formula recom 

 mended against the hop aphis and found it efficient only on 

 the nasturtium aphis (Af'/iii i-i/mids, L.), although it was 

 tested upon six othei- species. This solution was composed 

 of 03 gram- of quassia chips soaked for twentyfour hrans in 

 2,000 c.c. of water, to which fi>li oil soap was subseijuently 

 added in the proportion of IC. fc. of soap to 100 I'nitcd 

 States gallons of water. 



This mixture was also sprayed upon caterpillars of the 

 fall web worm (//!//'(?/'//•/" tv '/('(', I )ru.), and larvae of the 

 potato beetle {Lcplhidlnrsn <lcc(mli>iiala, .Say.), but these 

 were merely reduced to a state of stupor, from which they 

 recovered the following day. t^nassiin powder dusted on 

 web-worms had the .same effect on them, but caterpillars of 

 Jiomhw iiKiri, L., th>' silk-worm, were killed. 



The following summary of the remainder of the above 

 article is reproduced from the litrii'w oj Af>f>lii(l Eiitoiwli^sy, 

 Vol. V, tier. A, part I'.', December 1917. 



It gives the results of tlie experiments made by Messrs. 

 ilclndoo and Sievers to deteimine the best method for pre- 

 paring quassia extract, and to tied out the [ihtirmacological 

 effects of quassia extract, and (|Ud8siin on aphids. It also 

 gives the conclusions of the authois that owing tfi the po6r 

 ineecticldal properties oi quassiin and its expense, quiis.'iia 

 ■ extract can never become a general insecticide for all aphids. 



' I'lxfierimental tests for .selection of effective formulae 

 led to the conclusion that in making the extract a rtlatively 

 3ong [leriod of .soaking is es.sential in order to get the 



maximum quiintity of quassiin in solution; boiling the 

 chips in water for four hours t-xtracts I J times the amount 

 obtained by soaking them in cold water for twenty-four 

 liours; the smaller the chi|is and the finer the quassia powder 

 used, the greater the quantity of extract obtained; 

 the larger the quantity of w: ter used as a solvent, the greater 

 the quantity of extract; the addition of lye and soap to the 

 water materially increases the effectiveness of the extract. 



'As regards the pharmacological effects of quassiin.it 

 was found that exhalations from quassiin powder killed 

 aphids, but that those from quassia chips, quassia [lowdetv 

 and from solutions containing quassiin extract and (juassia 

 extract were ineffective. It wa~ also shown that quassia 

 extracts affected a[)hids only, and that ((uassiin extract does 

 not act as a stomach poison upon bers (Apis iihilitha) 

 or Rliagoh-tis pomonella. Quassia powder dusted on insects 

 had no effect, but quassiin powder killed them by affecting 

 the nervous .system, t^uas.sia and quassiin spray .solutions 

 killed aphid.s, if used sufficiently strong, their effectiveness 

 being increased by the addition of .soap. While nicotine 

 acts quickly and causes pronounced symptt>ms, quassiin acts 

 very slowly and causes but few, feeble symptoms, the aphids 

 slowly dying in a state resembling coma. 



'It is concluded that, owing to the poor insecticidal 

 properties of quassiin and its expense, ((uassia extract can 

 never become a general insecticide for all apiiids. A spray 

 solution made by soaking 22 BE), of quassia chips in 100 L'..S. 

 gallons of fish oil soap solution (Ifilh. soap to lOO I'.S. 

 gallons water) for twenty-four hours, was efficient on only twa 

 out of six species of aphids tested, while the residt was about 

 equal to that obtained bv using nicotine sulphate solution: 

 the expen.se was nearly the same, while owing to its slower 

 action it was much less reliable, as a shower of rain or the 

 migration tif the aphids nullifies its effects.' 



ANTldUA: HEFOirrON THE AGRICULTURAL 

 DEPAIlTMEXr rOI! THE YKAI: ES^DED MAI!(Jfl 



-.7. r.ri;. 



Muring the year under review the Motanic Gardens were 

 improved as to condition by a better drainage of a portion of 

 them, and as to appearance by the substituticm of a hedge of 

 breiid-and cheese in place of one of LJougainvillaea which was 

 not flourishing, as.iiot .s'uited to its situation, in the shallow 

 soil of the spot. 



A noticeable feature in the work of the nutseries during 

 the year has been the large number of cane seedlings raised, 

 no less than 1,1 1 1 having been grown from .seeds of e'x^i 

 different parent canes. After field tests the majority of these 

 will probably have to be discarded, but it is hoped that some 

 will be fottiid s|icciiilly suited to hical conditions. <«• suited 

 to other cane growing countries. One <ir two previously 

 raised Antigua seedlings are regarded with ap()ioval in some 

 districts in St. Kitts. The sendiitg cut of more than S.OOO- 



