> ~ - HS 8, . | is , Lye Ld Lan SA ek taee s . oe) 2 : * SAMUS act win) ee, . wi , “Yor + Sky aw be oe Cinsoiee Steageoares ~ eae. Sew arn eeerran ors . ease! Ne panier aeet > : ~ ‘ SS merace Re Soe aE : ae ~s en i. 2 etre titer ee eae ; : . c . . SS > my one : ea, m > yee nm Aen, Wel } AO, cs Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. Issued January 30, 1913. UeS Drak MEN OF SAGhICULTURE, BUREAU OF ENTOMOLOGY—CIRCULAR No. 166. L. O. HOWARD, Entomologist and Chief of Bureau. FLOUR PASTE AS A CONTROL FOR RED SPIDERS AND AS A SPREADER FOR CONTACT INSECTICIDES. BY WILLIAM B. PARKER, Entomological Assistant. ° € 10563°—13 WASHINGTON : GOVERNMENT PRINTING OFFICE : 1913 BUREAU OF ENTOMOLOGY. L. O. Howarpb, Entomologist and Chief of Bureau. C. L. Maritatr, Entomologist and Acting Chief in Absence of Chicf. R. S. CuLirton, Hxecutive Assistant. W. F. Taster, Chicf Clerk. F’. H. CHITTENDEN, in charge of truck crop and stored product insect investigations. A. D. HopKINs, in charge of forest insect investigations. W. D. HUNTER, in charge of southern field crop insect investigations. F. M. WEBSTER, in charge of cereal and forage insect investigations. A. L. QUAINTANCE, in charge of deciduous fruit insect investigations. E. F. Puiiiies, in charge of bee culture. D. M. RocGers, in charge of preventing spread of moths, field work. Rois P. Curriz, in charge of editorial work. MABEL CoLcorD, in charge of library. TrRuCK CROP AND STORED PrRopUCT INSECT INVESTIGATIONS. F. H. CHITTENDEN, in charge. C. H. PoPENoE, WILLIAM B. PARKER, H. O. MarsH, M. M. Hicu, Freep A. JOHN- STON, JOHN E. Grar, C. F. STaAnL, D. E. FINK, entomological assistants. A. B. DucKeETT, scientific assistant. I. J. Connpit, collaborator in California. W. N. Ord, collaborator in Oregon. THOMAS H. Jones, collaborator in Porto Rico. Marion T. VAN HorN, PAULINE M. JOHNSON, ANITA M. BALLINGER, preparators. Il CIRCULAR No. 166. Issued January 30, 1913. United States Department of Agriculture, BUREAU OF ENTOMOLOGY. L. O. HOWARD, Entomologist and Chief of Bureau. FLOUR PASTE AS A CONTROL FOR RED SPIDERS AND AS A SPREADER FOR CONTACT INSECTICIDES. By WILLIAM B. PARKER, Entomological Assistant. RESULTS OF EXPERIMENTS. During some spraying experiments for the control ef the red spider = Ye © i (Tetranychus bimaculatus Harv.) on hops in 1912 some difficulty was Fic. 1.—Lime-sulphur mixture and flour paste (left half), showing spreading effect of flour paste; lime-sulphur mixture straight (right half), showing beaded effect due to lack of flour paste. (Original.) experienced in obtaining an effective spreader for the lime-sulphur solutions, due to the fact that soap forms a precipitate with the cal- cium polysulphid. While testing the following combination—flow- 1 2 FLOUR PASTE AS A CONTROL FOR RED SPIDERS. ers of sulphur 15 pounds, water 100 gallons, and flour paste (as a “ sticker”) 4 gallons—a formula advised for red spiders in Bulletin No. 154 by Mr. W. H. Volck of the California Experiment Station, it was observed that the mixture spread over the leaves very readily. The flour paste was evidently the spreader and was accordingly mixed with the lime-sulphur solutions. The result was a smooth mixture which spread over the foliage very readily and gave unusual results as an arachnicide. The proper proportions were found to be 4 gallons of paste (4 pounds of flour) to 100 gallons of spray. Table I graphically represents the relative effectiveness of the lime-sulphur spray, with and without the flour paste, for the red spider on hops. TaBLE I.—Relative effectiveness of lime-sulphur spray, with and without flour paste, against the red spider on hops in the Sacramento Valley of California, in 1912. | i | Number Number | Per cent Formula. of mites of mites | of mites | present. killed. killed. Lime-sulphur, 36° Baumé, 1-75; flour paste, 4-100....................-...-- 698 692 Hime-sulphur:.s6°. Baume: 1-155 5505.2 oce oe eee ee 360 135 8 uc From the foregoing table it is very evident that the use of flour paste greatly increases the efficiency of the lme-sulphur spray and that without the paste the spray was very ineffective. These results were substantiated by other experiments and, by a check experiment with the flour paste, 4-100, used without the lime-sulphur, it was found that the increased efficiency was mainly due to the spreading effect of the paste. | Having proved a most efficient, cheap, and convenient spreader for the lime-sulphur solutions, some experiments were conducted with flour paste in combination with nicotine sulphate upon the hop aphis (Phorodon humuli Schrank). (See Table IT.) TABLE II.—Results obtained by spraying ivith combinations of flour paste and nicotine sulphate in different proportions against the hop aphis, Sacramento Valley of California, 1912. Number eae | Cost per Formula. of aphides Pee. 100 | present. | * | gallons. | Per cent. Cents Nicotine sulphate, 1-2,000; flour paste, 4-100......................-......- 627 | 100 0.71 Nicotine sulphate, 1-2,500; flour paste, 4-100.....................-.......- 611 | 100 . 60 Nicotine sulphate, 1-3.000; flour paste, 4-100......................-....... 1, 668 | 99 50 Nicotine sulphate, 1-3,000; flour paste, 4-100.............................. 148 99 50 From the preceding table it is very evident that flour paste, 4-100, is a very effective spreader for nicotine sulphate. The efficiency of flour paste as a spreader was very evident to the writer, but it was deemed advisable thoroughly to illustrate this point. FLOUR PASTE AS A CONTROL FOR RED SPIDERS. 3 Two hopvines were accordingly sprayed, one with lime-sulphur straight and the other with lime-sulphur and flour paste, 4-100. The relative spreading effect of these two sprays is shown in fig- ure 1. The left half of the figure represents the lime-sulphur and the flour paste in combination, while the right half represents the lime-sulphur straight. The spotted effect produced by the lime- sulphur mixture alone is in strong contrast to the even appearance of the other half of the illustration. During some spraying experiments with nicotine sulphate and flour paste upon the hop aphis it was observed that many of the smaller aphides had become pasted onto the leaves. From this data it was assumed that a stronger solution of paste would be effective against the more delicate aphides and mites, and the following experiments were conducted upon the red spider. TABLE III.—Results of experiments with flour paste sprayed against the red spider on hops in the Sacramento Valley of California, 1912. | Number ites Cost per Date. Formula. | of mites Ralled | present. * | gallons. ! UNE RES SHOUPIPAaSteyS— | O0mataes sat a eee he ane cee a= teens one aul 435 100 17.6 June) 2a |aeece CONS Lat i, ae i atc pe ig SOY ac SPS, PME Egy Sane 781 99.8 17.6 digi eons ee ra coy rae nr eT aes aR nae vay are Ria STS 452 99.8 156 ATg29 6 |Ss=s- LOR eee oe are Ue agains neato rie ieee ead cas 882 100 17.6 tisk OOF as a SRR a TS Cea a en ie et RR 477 100 17.6 PAU Beemer ets ote ee emer ees eres Se et een ae ey 732 99.8 17.6 POAC OUNt ee Sots a Sars oe ar eee iets wad shee Aeieeie oe | B19 (Gs) | lssesceooao esaccnoodc IXY SONGS Soo oho BOC CIO Te ROSES SE REE GeO Ree Saas seamen UES Oalsasaaoeaoc FUyabL ON SEOUEPAStS LO TOUNe ie oa eae Pe ee 805 99.9 22 BAN Oe Gil arererey= CL ge tera eye pete ee el hE ee eee ee eT in Uren, A an 908 99.9 22 | Rotalicoun bets le aaa eee os ee ee seems ny 73 Dao cee Selec | PSV OLN Cet see Ey Sais Anata A nr Ae create a sss wees 99.9 |...------- These experiments prove that flour paste, 8-100 and 10-100. is effective against Tetranychus bimaculatus. The paste has no effect upon the eggs, however. and in controlling the mites a second application 7 to 10 days after the first is necessary to catch the mites that emerge from the eggs.* A few preliminary experiments were conducted with this material upon Tetranychus mytilaspidis Riley which was attacking pears, with very encouraging results, and it is very probable that flour paste, 8-100, will give good results when applied for any of the small leaf- feeding mites. | The last of June, 1912, flour paste, 8-100, was applied for the hop aphis (then in the younger stages) with a 97 per cent efficiency. These were encouraging results, but later experiments proved that, *In moderate weather allow 10 days and in hot weather 7 days between applications. | | oy FLOUR PASTE AS A CONTROL FOR RED SPIDERS. although the solution was effective against some very delicate species and the vounger stages of the hop aphis, it was not effective against the stouter aphides. When the paste was dry the mites and more delicate aphides treated were found firmly pasted onto the leaves. Later the paste film was observed to crack and partially scale off, leaving the leaf free to perform its natural functions. The neutrality of this spray was proved by the fact that when epphed upon the foliage and blossoms of the hop in proportions as high as 12 pounds to 100 gallons no injurious effect resulted. When sprayed onto the burrs and delicate hop cones it did not pre- vent pollination or injure the appearance of the scales. Flour paste has proved effective when applied for red spiders upon the following plants: Beans. Pumpkin. Chrysanthemum (may spot leaves if | Pear, used too near blossoming time). Prune. Hops. Roses in field. Cucumber, greenhouse and field. Violets, field and greenhouse. The flour paste was not satisfactory when used for the red spider on greenhouse roses (did not spread well), greenhouse carnations, or field sweet peas. PREPARATION OF PASTE. To prepare the flour paste, mix a cheap grade of wheat flour with cold water. making a thin batter, without lumps; or wash the flour through a wire screen with a stream of cold water. Dilute until there is 1 pound of flour in each gallon of mixture. Cook until a paste is formed, stirring constantly to prevent caking or burning. Add sufh- cient water to make up for evaporation. Flour paste may also be prepared by stirring boiling water into a moderately thin batter until there is 1 pound of flour in each gallon of mixture and allowing it to stand until the starch is all broken down. If the paste is not sufficiently cooked, the resulting spray will not be effective, and if overcooked the paste will harden when thor- oughly cool, and will not mix with water very readily. Usually, however, the paste is. used as it is prepared, and overcooking is not a disadvantage. When mixed in the spray tank flour paste has a tendency to settle, and in order to do satisfactory work agitation is necessary. This is but a slight disadvantage, and is necessary with most materials. Flour paste appears to be a very effective spreader for lime-sul- phur and nicotine-sulphate sprays. Cheap flour can be purchased FLOUR PASTE AS A CONTROL FOR RED SPIDERS. 5 for less than half the cost of whale-oil soap. It is always obtain- able, and having no odor it is less offensive to use than the whale- oil and fish-oil soaps. When used alone at the rate of 8 gallons (8 pounds flour) to 100 gallons of water it is effective against several leaf-feeding mites and some very delicate aphides. The possibility Fic. 2.—Hindu making flour paste, Sacramento Valley, Cal., 1912. (Original.) of its use as a spreader for lime-sulphur sprays for scale insects and fungi and as a “ sticker ” for arsenicals has not yet been worked out, but from observations during the past four months it is believed that it may have some value along these lines. Approved: JAMES WILson, Secretary of Agriculture. Wasuinerton, D. C., November 23, 1912. DDITIONAL COPIES ofthis publication may be procured from the SUPERINTEND- ENT OF DOCUMENTS, Government Printing Office, Washington, D. C., at 5 cents per copy 7 ae 7 ms =i Vee Th sie ris ae Pie i eve, AL) Pie oe as 7 : pas eas ron — oe 1 Se ea 3 is Lays 4 yh (ena vy a ; oh pees ,*) Sook alee ve a ss ss = Oss on: hi Mas 4 Te a Ande : phe: eet SO aerenl é pata?) - > ots - ve See ~~ ew o>, “~%. 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