Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. a. en gn r 7 , UNITED STATES DEPARTMENT OF AGRICULTURE BULLETIN No. 771 (gh ~ Contribution from the Bureau of Entomology L. O. HOWARD, Chief Washinigioa, Dc. PROFESSIONAL PAPER :- February 21, 1919 A STUDY OF THE EFFECT OF STORAGE, HEAT, AND MOISTURE ON PYRETHRUM By W. 8. Azssott, Scientific Assistant CONTENTS Page Page Rettroductiony aed 6, fea sa4% bok ono edaonc 1 | Effect of storage in sealed glass containers. . . 3 MevHods Of DeStiniey- =. 52. .--hsc<-0c- se ose 1 | Effect of soaking in hot or cold water.......- 5 Effect of exposure to the weather and in a Effect of exposure to dry heat... - ! Wo see 5 ROOM Rett: oc nviia sears ses ofeseiiiale toc 2 PO UTMUINATY) Pe eile oe eas nese ceiree: ay a arenes 6 INTRODUCTION = It has been generally accepted by entomologists that pyrethrum powder deteriorates rapidly under ordinary conditions of storage, but few or no data have been advanced to support this theory or to show under what conditions or how rapidly such deterioration takes place. The following experiments, made at the testing laboratory of the Insecticide and Fungicide Board of the United States Depart- ment of Agriculture, Vienna, Va., were conducted to ascertain the effect of exposure to heat, moisture, and the weather, and of storage in sealed glass containers, on whole and ground flower heads of Pyrethrum cinerariaefolium (Trev.). METHODS OF TESTING Two methods of testing the pyrethrum powder were used: (1) By dusting and (2) by dipping. In the dusting tests small potted nasturtium plants, grossly infested with aphids (Aphis rumicis Linnaeus), were thoroughly dusted by means of a small hand dust gun. In the dipping tests large specimens of the German roach or Croton bug (Blattella germanica Linnaeus) were dropped into a beaker con- taining a small amount of the pyrethrum powder to be tested, and the beaker was given a shake so that the insects were thoroughly covered with the powder. Each roach was then placed in a separate 8-ounce bottle and observed at frequent intervals, the time when the insect became inactive, i. e., unable to walk, and the time of death 96301°—, 19—Bull. 771 a ge ae a — —— a i _ rare = ———————————eeEeEeEeEeEeEeEeeeeEeeoEEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeeeeeeeEeEeEyEyEyEyEyEyEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEeEEE—Es~ 2, BULLETIN 771, U. S. DEPARTMENT OF AGRICULTURE being recorded. With each set of experiments checks, consisting of 10 roaches dipped in fresh pyrethrum powder and 10 untreated, were used. The average mortality for the untreated roaches was found to be less than one roach in 108 hours, which is so small that the untreated series were omitted from the following tables. EFFECT OF EXPOSURE TO WEATHER AND IN A ROOM Table I shows the killing effect on roaches of whole and ground flower heads that had been exposed to the weather or in a room for various periods of time. TaBLe I.—Hfectiveness against roaches of whole and ground pyrethrum flower heads exposed to the weather or in aroom. Ten roaches dipped for each test Hours required to kill. No. Material. Exposed— pelea ‘| First Last | AG roach. | roach. verage. 1}) Wiholeflower headS= 22 s55---2--.-e5 To weather......- 2 19.3 43.3 S189 Hh iesaae (CUO Naan eae ce eas fos ll deena | bphien eerk OKO el Sn Wega 12 19.6 92.1 34.6 ile LO ee ees Fae COME ac oes 21 23.2 | 3active at end of 120 : hours. 4q GroundiflowemheadSeeeere 2 ec ce eeleseee (COR Mee a Ee 2 19.5 64.5 35 Disloas ee GOs eae ee ee sce ee GOELE 232 5 2222 12 19.6 47.6 29.8 G3) ee (Oe Ee debs poner sac o7 Bae EeESeeee Meee GO sani eae ‘ 21 23.4 | 4active at end of 120 hours. 7 | Whole flower heads. ................. in nOOmMe 22 eee. 2 24. 64.8 43.1 Sie we COUR a ee en ees. walle eee CO ek eee 12 19.8 92.3 39 ee GOs. . CER EE st RIS ED Gow eater Bm 21 14.5 71.9 31 OMe (CXS Ie Se Std oe Soe Ae Se ESE Eoin (OVO Soe ae 34 22.4 67 40.7 Hida ee Be GO ee eee eM. eee GOs A Aas. 150 18 44.5 22 125" Groundtflowerheads= 8---.,.- s.f4sse\eaees COLOR. Bee ase 2 19.5 64.5 39.5- JS Shoe ee GOI Ee ee BAe. ASPEN SD eo GoLee. 2 aw 12 19.7 | 43.9 26 Ree see OGY eae See See ene tees 8 lhe opie COVo ns Meee ee, 21 EGult| 27.5 22 Tae ae GOP ee ee en ec SEER Gow.tA eae 34 PPM 46.5 36.4 G2 | eee CO RSE BH SEE GG 5 a BS ey See eee done gale. 136 PAa 1 pellye aie! at end of 120 | Zee eek (OO See OEE Sc one oO RS ONC RSE Eee dos eee 150 42.1 | 8active at cand of 120 ours. 1Sil wWwholewiower heads: fayse sea ee In sealed | janSeeeee 150 17.5 41.5 25.2 LOD Ground Howerheadsee sss ts eee. ae oe Oke, ae eee 19.3 43.3 36.2 PAU Beas (CER ES: 5a rsh SERGE 27m Nal RE a6 RSE rs) en 12 19.9 44 27.4 21 ares (GK ene SS A ee SS ER oe i ae i a Oe eee 21 23.5 47.5 30.7 Dd |e ene C10) SA a en L COA ee 34 18.3 46.9 35.2 DBy.| |e ania GOR Pa Gy See tA Na I ot dots S72 eee 136 22.3 46.3 28 Daa eee (ONO se vee a Sir ah a en ee ae nes 2 ee GOs earns 150 17.9 44,1 “21.9 1 Probably injured in dipping. The material used in these experiments was received as whole flower heads in April, 1915, when it was divided into six lots which were treated as follows: No. 1. Whole flower heads, in a dare open glass cylinder, were placed out of doors where hae were fully exposed to the sun, wind, and rain. No. 2. Powdered Le heads, sifted to 80 mesh, were exposed as in lot No: 1. . No. 3. Whole flower heads were placed in a shallow dish and al- lowed to stand on a shelf in the laboratory. No. 4. Powdered flower heads (80 mesh) were exposed as in lot No. 3. EFFECT OF STORAGE, HEAT, AND MOISTURE ON PYRETHRUM S No. 5. Whole flower heads were kept in a tightly sealed fruit jar in the laboratory. No. 6. Powdered flower heads (80 mesh) were kept as in lot No. 5. At the times indicated in the table portions of these six lots were ground, sifted to 80 mesh, and tested against roaches by dipping the insects as described on page 1. This table shows that an exposure to the weather for 12 weeks does not noticeably injure ground or whole flower heads, but that an exposure of 21 weeks materially reduces the efficiency of both, since at the end of this time they killed, in 120 hours, only 60 and 70 per cent, respectively. | When whole flower heads were exposed in an open dish in the laboratory for 150 weeks, they retained their full efficiency. Under the same conditions the powdered flower heads showed some de- terioration in 136 weeks, and were of almost no value at the end of 150 weeks. Both flower heads and powder showed no loss of effi- ciency when kept in tightly closed jars for 150 weeks. EFFECT OF STORAGE IN SEALED GLASS CONTAINERS Tables II and III give a comparison of the effectiveness against aphids and roaches of whole and ground pyrethrum flower heads stored in glass containers for 54 years. The materials considered in these tables were received as whole flower heads in 1911. A portion of each sample was ground early in 1912 and stored in a tightly stoppered bottle. The remaining flower heads were stored in sealed fruit jars under the same condi- tions until March, 1918, when a portion of each lot was ground and tested in comparison with the powders prepared in 1912. TaBLE II.—A comparison of the effectiveness against aphids of whole and ground pyr- ethrum flower heads stored in glass containers for 5% years. One nasturtium plant, grossly infested with aphids, dusted in each test Num-| Ground in spring | Num- No. Material. ber of 0f1912; tested | ber of Ground and tested, March, 1918. tests.| March, 1918. tests. 1 | California flowers....... ' 4 | Ineffective...... 4 | 80-90 per cent killed or repelled. 2 | Montenegrin flowers... . ABS cislova GOvsasucseeate 4 | 80-95 per cent killed or repelled. 3 | Dalmatian flowers. ..... Ai eeesaras (0 (orev 2 | 90 per cent killed or repelled. TaBLe III.—A comparison of the effectiveness against roaches of ground and whole pyrethrum flower heads stored in glass containers for 54 years. Ten roaches dipped for each test Ground and tested in March 1918—Hours required to - kill— ‘ Ground in spring of 1912, tested March No Material. 1918—Hours required to killroaches. * |— First Last roach. | roach. |4Verage 1 | California flowers......- kA ed inl ZO NOUWTS 482 o cers misc ooc/- 8 oe wine 18.5 44 32 2 | Montenegrin flowers....| 5 killed in 120 hours................-..--.- 18.9 72.8 36. 7 3 | Dalmatian flowers. ..... Gpkaledtine Oh ourse sess eee case eae 19.5 72 40.3 = BULLETIN 771, U. S. DEPARTMENT OF AGRICULTURE As will be noted in Table II, the powders ground in 1912 were ineffective in 1918, when tested against nasturtium aphids. Whole flower heads from the same stock, which had been kept in sealed fruit jars for 54 years and were ground in 1918, killed from 80 to 90 per cent of the treated aphids. Fresh pyrethrum tested at the same time killed 90 per cent. Table III gives the results of dipping tests against roaches with the same materials as used in Table II. In every case the powders ground in 1918 were found to be effective, all of the roaches being killed in from 32 to 40.3 hours, while in no case did the powders ground in 1912 kill all of the dipped roaches in 120 hours. Fresh pyrethrum, used at the same time, required on the average 31.3 hours to kill 10 roaches. These tests show that pyrethrum powder kept in tightly stoppered bottles for 54 years loses practically all of its effectiveness, but that the unground flower heads stored under the same conditions for the same length of time are practically un- hurt. Table IV shows the effect, on powdered flower heads, of 54 years’ storage in tightly stoppered bottles or sealed glass fruit jars. TasLe [V.—A comparison of the effectiveness against nasturtium aphids of freshly ground Dalmatian closed flower heads and of the same powder after it had been stored in tight glass containers for 54 years. One nasturtium plant, grossly infested with aphids, dusted for each test Dalmatian closed flower heads ground in spring of 1912. Cra Tested November, 1912. Tested March, 1918. No. Material. ree Num-} Length Num-| Length ber of of Results. ber of of Results. tests. | tests. tests. | tests. Days. Days. 1 | Wild flowers......-- 1908 1 1 | 98 per cent killed... 4; . 7) Ineffective. Dil aes GOzs <6 S see 1909 2 2| 95-100 per cent 2 7 Do. ed. See a Ole ec OTTO 2 4 | 99 per cent killed. . 2 7 IYO! 4 | Cultivated flowers...| 1908 2 2/100 percent killed.|. 4 7 | Slightly effective. EL OM So 2 eine 1909 2 Di aee = Oar hee Seren 2 7 | Ineffective. Gio GoM seis Staats 1910 12 ilsenos Gor eee seen 2 7 Do. 1 The cabbage aphis (A phis brassicae Linnaeus) was used in these tests. The materials used in these tests were received in 1911 as whole flower heads, which were ground and sifted in the spring of 1912, and stored in sealed fruit jars or tightly stoppered bottles. These powders were tested against nasturtium aphids in November, 1912, and again in March, 1918. As will be noted, all of these powders were found to be effective in November, 1912, and of almost no value in March, 1918. It is therefore evident that pyrethrum powder stored in sealed glass con- tainers for 54 years wil! lose practically all of its efficiency. EFFECT OF STORAGE, HEAT, AND MOISTURE ON PYRETHRUM 5 In connection with the deterioration of unground flower heads, it is of interest to note that, in the 1912 tests, practically no difference in effectiveness was found between the 1908, 1909, and 1910 crops, which indicates that the flower heads are not noticeably injured in four years under the commercial conditions of storage. EFFECT OF SOAKING IN HOT OR COLD WATER Table V shows the effectiveness against roaches of pyrethrum pow- der which had been soaked for 24 hours in hot or cold water. TaBLe V.—Effectiveness against roaches of pyrethrum powder soaked for 24 hours in hot or cold water. Ten roaches dipped in each test Hours required to kill. No. Treatment. First roach.| Lastroach.| Average. Heres RECks UNtreatedeese ts)... See een Ul RR ETN SAC al | 21 35.9 25. 4 Dri Soaked i ThaTCerO) Ko Ty AEN a) Bae Ss eS at Che eye ale ENN ae UN DA SreaRGE OIE 21.9 48.2 38.9 3 Soakedhinvhoe watery sscn ce ses ee aN ee a ek Mek Sc Se 2 oe pine at end of 94 ours 1 Probably injured in dipping. The material used in test No. 1 was prepared by soaking 20 grams of pyrethrum powder (80 mesh) in 100 c. c. of cold water for 24 hours. The water was then filtered off and the powder dried at room tem- perature and resifted to 80 mesh. The material used in test No. 2 was prepared in the same way, boiling water being used. This table shows that pyrethrum soaked for 24 hours in cold water killed all of the dipped roaches in 48.2 hours, but required on the average 13 hours longer to kill than did the untreated powder. The pyrethrum treated with hot water killed only 9 roaches in 94 hours. It is therefore evident that cold water removes some of the active ingredients from pyrethrum powder, but not as much as is removed by hot water. EFFECT OF EXPOSURE TO DRY HEAT Table VI shows the effect on ground flower heads of exposure to dry heat for 18 hours. TasLe VI.—EHffectiveness against roaches of pyrethrum powder exposed to dry heat for 18 hours. Ten roaches dipped in each test Hours required to kill. No. | Temperature. First roach.|} Lastroach.| Average. SOR Ge) Fe ty pee i Re See iar, Be eee ee URN 9. kL 1 dead in 48 hours. 1 2 : 5 3 ioe (Ce align heh Ss ca ii ae ates Maly Gr ta cay a te ie ae 6 ST Sa PALE AL 47.4 4 Fa aL AQ ra Crtne ame oie emer oa YC RMR L(y Set eee De Ah N at dead in 48 hours. Eis | | ‘ | 6 BULLETIN 771, U. S. DEPARTMENT OF AGRICULTURE The materials used in these tests were placed in open tubes and heated for 18 hours at the temperature given. The results show that an exposure to a temperature of 120° C. (248° F.) for 18 hours does — not noticeably injure pyrethrum powder, but that a temperature of 130° C. (266° F.) or 140° C. (284° F.), for the same length of time, either destroys or drives off the active principle. SUMMARY 1. Whole and ground flower heads kept in sealed fruit jars for 150 weeks were not injured. 2. Ground flower heads kept in tightly closed glass containers for 54 years lost practically all of their effectiveness. 3. Whole flower heads kept in tightly closed glass containers for 54 years were practically unhurt. 4. Whole flower heads exposed in an open dish in a room for 150 weeks were not injured. 5. Ground flower heads were not injured by an exposure for 34 weeks in an open dish in a room. Their value was materially re- duced by an exposure of 136 weeks and they were practically worth- less at the end of 150 weeks. 6. Whole and ground flower heads were uninjured by an exposure to the weather of 12 weeks, but an exposure of 21 weeks greatly re- duced their efficiency. | 7. Powdered flower heads heated at 120° C. for 18 hours were practically uninjured, but a temperature of 130° or 140° C. for the same length of time destroyed practically all of their effectiveness. 8. Ground flower heads were slightly injured by soaking for 24 hours in cold water, and materially injured by soaking for the same length of time in hot water. PUBLICATIONS OF THE UNITED STATES DEPARTMENT OF AGRICULTURE RELATING TO INSECTICIDES. PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION. Arsenate of Lead as an Insecticide Against Hornworms in Dark Tobacco Districts. (Farmers’ Bulletin 595.) Hydrocyanic-Acid Gas Against Household Insects. (Farmers’ Bulletin 699.) Carbon Disulphid as an Insecticide. (Farmers’ Bulletin 799.) Tobacco Hornworm Insecticide. (Farmers’ Bulletin 867.) . Fumigation of Ornamental Greenhouse Plants with Hydrocyanic-Acid Gas. (Farmers’ Bulletin 856.). Information for Fruit Growers About Insecticides, Spraying, Apparatus, and Im- portant Insect Pests. (Farmers’ Bulletin 908.) Spraying for the Control of Insects and Mites Attacking Citrus Trees in Florida. (Farmers’ Bulletin 933.) Commercial Bordeaux Mixtures: How to Calculate Their Value. (Farmers’ Bul- letin 994.) Cactus Solution as an Adhesive in Arsenical Sprays for Insects. (Department Bul- letin 160.) Quassiin as a Contact Insecticide. (Department Bulletin 165.) A Method of Fumigating Seed. (Department Bulletin 186.) Chemical Composition of Lime-Sulphur Animal Dips. (Department Bulletin 451.) Fumigation of Ornamental Greenhouse Plants with Hydrocyanic-Acid Gas. (De- partment Bulletin 513.) A Study of the Effect of Storage Heat and Moisture on Pyrethrum. (Department Bulletin 771.) Spraying for White Flies in i Blonde: (Bureau of Entomology Circular 173.) PUBLICATIONS FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, GOVERNMENT PRINTING. OFFICE, WASHINGTON, D. C. Important Insecticides, Directions for Preparation and Use. (Farmers’ Bulletin 127.) Price 5 cents. Para-dichlorobenzene as an Insect Fumigant. (Department Bulletin 167.) Price 5 cents. Homemade Lime-Sulphur Concentrate. (Department Bulletin 197.) Price 5 cents. Miscellaneous Insecticide Investigations. (Department Bulletin 278.) Price 10 cents. Fumigation for Citrus White Fly, as Adapted to Florida Conditions. (Bureau of Entomology Bulletin 76.) Price 15 cents. Fumigation Investigations in California. (Bureau of Entomology Bulletin 79.) Price 15 cents. Fumigation of Citrus Trees. (Bureau of Entomology Bulletin 90, Part 1.) Price 20 cents. Lime-Sulphur as Stomach Poison for Insects. (Bureau of Entomology Bulletin 116, Part 4.) Price 5 cents. Use of Hydrocyanic-Acid Gas for Fumigating Greenhouses and Cold Frames. (Bu- reau of Entomology Circular 37.) Price 5 cents. Flour Paste as Control for Red Spiders as Spreader for Contact Insecticides. (Bureau of Entomology Circular 166.) Price 5 cents. Insecticide Studies, Pyrethrum Powders Containing Poisonous Metals: Compilation of Analyses of Insecticides and Fungicides: State Laws Governing Composition and Sale of Insecticides. (Bureau of Chemistry Bulletin 76.) Price 5 cents. Lime-Sulphur-Salt Wash and Its Substitutes. (Bureau of Chemistry Bulletin 101.) Price 5 cents. Lead Arsenate: 1, Composition of Lead Arsenate Found on Market; 2, Homemade Lead and Chemicals Entering Into Its Manufacture; 3, Action of Lead Arsenate on Foliage. (Bureau of Chemistry Bulletin 131.) Price 15 cents. O 7 "a 4 i 8 Soe RN 3 . 7 ‘ ry \ in f : - .