Document GKJkjy5qO1N6N6yxJ2wqyjrE4

158 Journal of Economic Entomology Vo!. 46, So. ] On July 11 nnd 12, whcD the application* were liepun, the holt weevil infestations throughout all plots were ns nearly alike as is usually true under field conditions. From 2S to 28 per cent of the squares were punctured in the dust experiment and from 2S to 2!) per cent in the spray experiment. Practically no square infestation by the bollworm was recorded at this time. Control of the boll weevil was excellent with all insecticides tested. There was no significant differ ence between tbe three dosages of heptachlor (Table 1) or between dusts nnd sprays. Both boll weevil and liollworm caused excessive injury in the check plots, and the reduction in yields in the two plots were approximately the same. Any differ ence in yield between treatments was due to soil variations and moisture levels and not to a difference in insect control. Toward the end of the season aphids became fairly numerous where the spray was applied, prob ably as a result of the prolonged use of DDT for bollworm control. However, control measures were not required. In the spray experiment the infestation of spider mites was much lower than that of aphids, whereas in the dust experiment the infestations were approximately equal. Summabt.--Two field experiments were con ducted at Stoneville, Miss., to determine minimum dosages of heptachlor required for the control of the boll weevil, Anihonomus pandit Boh., and its effect on other cotton pests. Tractor equipment was utilized to apply dusts and sprays. Dusts containing 2.5, 8.5, and 5.0 per cent of heptachlor were com pared with each other and also with dusts containing 2.5 per cent of aldrin, 1.5 per cent of dieldrin, and impregnated BHC containing 8 per cent of the gamma isomer. There was no significant difference n boll weevil control obtained between concentra tions of heptachlor or between heptachlor and any of the other insecticides. To control the bollworm 10 per cent DDT dust was applied in two separate ap plications. Emulsion sprays containing heptachlor gave boll weevil control similar to that obtained with dusts in equivalent dosages and equal to that of aldrin and dieldrin. Control with BHC dusts and chlordane sprays was about the same. DDT at the rate of 0,5 pound per acre was included in each treatment from August 2 to September 4 for control of the bollworm. Apparently heptachlor had very little effect on in festations of the cotton aphid and spider mites. It is concluded from these experiments, and from other observations and tests made in 1949 and 1950, that heptachlor at 0,25 pound per acre in either dust or spray is sufficient for control of the boll weevil under the conditions existing at Stoneville, Miss. Chlorinated Polyphenols to Improve Lindane Residues W. N. Sullivan and In wtn Hornstein, V.S.D.A. Agr. Res. Adm., Bureau of Entomology and Plant Quarantine Tbe use of lindane as a pesticidal residue is well established. On some surfaces the residue is unsightly and it generally dissipates within a few weeks, owing to the relatively high vapor pressure of lindane (9.4 X10-4 mm. Hg. at 20' C.). Studies were there fore initiated to improve both tbe appearance and persistence of lindane residues. Previous work by Block (1948) and Lindquist el al. (1945) proved that DDT can be incorporated into resins and paints. IVe chose to blend lindane with a chlorinated polyphenvl for the following reasons: (1) Chlorinated polyplienvls are obtainable as bigbroolerular-weight, rioncrystallizing, film-forming ma terials. (2) Since both these materials are chlorinated hydrocarbons, it was expected that lindane would be soluble in the polypheny) and therefore would show no tendency to crystallize out of such films. (S) Tbe vapor pressure of such mixtures is lower than that of lindane alone, and thus the effective life of lindane would be extended. (4) Chlorinated polyphenyls would not be expected to discolor or change their physical characteristics with time. Paints and poly merizable films such as urea formaldehyde may change in time. Paints may form a hard skin impervi ous to lindane diffusion, and polymerizable ma terials, in addition to discoloring, may continue to polymerize and eventually cause the lindane to crys tallize out of the film. Chlorinated polypbenyls are inexpensive, non oxidizing, of low volatility, noncorrosive to metals, and resistant to fire and water. They are available under the trademark Arodor.1 Materials and Methods.--Because of good pre liminary results, the chlorinated polyphenyl used in these tests was an isomeric terpbenyl (ortho, meta. and para mixture) containing about 60 per cent of chlorine by weight and commercially available as Aroclor 5460. It forms a yellow transparent resin with a very low vapor pressure. Carbon tetrachloride solutions of lindane and the chlorinated polyphenyl, separately and together, were prepared iD several concentrations. The test solutions were poured on aluminum and masonite panels each 1 square foot. The spreading properties of the solutions were excellent. The carboD tetra chloride soon evaporated, leaving the lindane as a white deposit, the mixture as a clear residue that was tenacious and slightly tacky, and the chlorinated polypheDyl as a bard, transparent residue. Tbe panels were placed iD a horizontal position and held at summer room temperature (70-)00 F.) for 8 months. Large nymph and Bdult roaches, Periplaneta americana (L.), were used as test insects. .After 2, 10, 80, 60, BDd 90 days, 15 roaches were confined for 2 hours under each of two petri dishes inverted over each test panel. The roaches were thus exposed to the contact and fumigation action of the residues on tbe test panel. They were then transferred to obser-. vatioD cages and held for 4 days. Results.--The results of the tests are given in table 1. The effective life of a lindaDe residue, as measured by a 50 per cent or better kill of roaches od an alumi num surface, is shown to be dependent on the amount of lindaDe used. LindaDe residues of 50, 100, and 200 mg. per square foot were effective under summer conditions for less tbaD 15, 80, and 60 days, respectively. These were the periods during which the white deposit was visible. Tbe effective period was greatly increased when lindane was mixed with the chlorinated polyphenyl. A 6G per cent kill was obtained when the roaches were exposed to 80-dav-old residues containing 50 mg. of lindane plus 200 mg. of chlorinated polv- 1 Tbe Aroclors, physical and chemical properties and suggested application*. Application Data Bulletin No. P-315, Monsanto Chemical Co., SL Louis, M o. l'ci.r, Tat residt Do- M Lind. 5' Id 20: 5' 101 etb 20: pliuny liudii ..pun olil.-r .I'M. ' and >! dam-1 cffn.-li of till Mirf.ir His ,-isleii' by iiv pheny rvmni: lindan rIIv re surfin' there iniirs 1 The and ti flirt Ilf bring Block Linde Iric.ii Mas: Du fnrap. t\ en i -rn-O) a ur\ surve Alula C uni' val- < a. Hue WATER PCB-SD0000039117 Journal, ok Economic Entomouhiy Vol. 46, No. 1 On July H uml 12, when the applications were begun, the boll weevil infestation* throughout nil plots were us nearly alike as is usuully true under iichl coinlitions. From 23 to 2B per cent of tile sqimrcs were pum lureil in the (lust experiment and from 23 lo 20 per cent in the spray experiment. I'raelieally no square infestation by the bollworm was recorded ul this lime. Control of the boll weevil wns excellent with all insecticides tested. There was no significant dilferencc between the three dosages of heptnehlor (Table 1) or between dusts and sprays, llotli boll weevil uml hollworni caused excessive injury in the check plots, and the reduction in yields ill the two plots were approximately the same. Aliy differ ence in yield between treatments was due to soil variations and moisture levels uml not to a difference in insect control. Toward the end of the season aphids became fairly numerous where the spray was applied, prob ably as a resulL of the prolonged use of DDT for bollworm control. However, control measures were not reipiired. In the spray experiment the infestation of spider miles was much lower than that of aphids, whereas in the dust experiment the infestations were approximately cipiat. Summiuy.--Two field experiments were con ducted at Stooeville, Miss., tu determine minimum dosages of heplaeldor reipiired for the control of the ladl weevil, Atilhunomus grundis Hole, and its elfeet on other isiltoo pests. Tractor equipment was utilized to apply dusts ami sprays. Dusts containing 2.5, 3.5, and 5.0 per cent of hcptuclilor were com pared with each other ami also with dusts continuing 2.5 per cent of iihlrin, 1.5 |a-r cent of dicldrin, ami impregnated UIHI eoiilaiiiiug 3 per eenl of the gamma isomer. There was no significant difference in ladl weevil control obtained between conical rulious id hcplnchlor or between heplaeldor and any of the other insectieides. To control the bollworm 10 per cent DDT dust was applied in two separate ap plications. Emulsion sprays containing lieplaeldur gave boll weevil control similar to tliul obtained with dusts in equivalent dosages and equal to that of ahlriu and dicldrin. Control with HUE dusts uml chlordanc sprays was about the same. DDT at the rale uf 0.5 pound per uerc was included in each treatment from August 2 to September 4 for control of the hollworni. Apparently heptaehlnr had very little elfeet on infestnlioiis of the cot ton aphid and spider miles. It is concluded from these experiments, and from other observations and tests made in 1010 and 1350, that lu-pluehlor at 0.25 pound per acre in either dust or spray is sullieicut for control of the ladl weevil miller the conditions existing at Stoiieville, Miss. (.hloriiinlcd Polyplienyls lo Improve Lindane Residues W. N. Sullivan am) Iuwin IIoiinutkin, U.S.D.A. L" hV' iti'n Hi,rtuiu i`f I'nUmiiilutjy am/ Previous work by lllock (til IB) uml Lindquist etui. (1015) pruved that DDT can he incorporated into resins ami paints. We chose to blend lindane with a chlorinated pnlyphcnyl for the following reasons: (I) Chlorinated polyphenyls are obtainable us highmolecular-weight, uuncryslulliziug, film-forming inaIcrinls. (2) Since both these materials are chlorinated hydrocarbons, it was expected that lindane would he soluble in the imlyphcuyl and therefore wuuld show no tendency tu crystallize out of such films. (3) The vapor pressure uf such mixtures is lower Hum that of limlaiie alone, and thus the elfeclive life of lindane would he extended. (4) Chlorinated pulyphcuyls would not lie expected to discolur Or change their physical characteristics with time, l'uints and polymerizuhle films such us urea formaldehyde may change in lime. Paints may form a hard skin impervi ous lo liudunc diffusion, and polymerizable ma terials, in addilimi to discoloring, may continue tu polymerize nml eventually cuuse the lindane to crys tallize out of the film. Chlorinated polyphenyIs are inexpensive, non oxidizing, uf low volatility, nuneorrosive to nietuls, and resistant to fire and water. They are available under the tnulemark Aroclur.1 Matkuials and MltuOos.--Rccuusc of good pre liminary results, the chlorinated |>o)yplienyI used in these tests was an isomeric Icrphcnyl (ortho, mciu, uml puru mixture) containing about DO per cent of chlorine by weight and commercially uvailublc as Aruolor 6i00. It forms n yellow transparent resin with a very low viqair pressure. Carbon tetrachloride solutions uf lindane and the chlorinated polyplicnyl, separately and together, were prepared in several concentrations. The test solutions were Jhoired on aluminum and masonite panels each 1 square foot. The spreading pro|>erlies of the solutions were excellent. The carbon tetra chloride soon evaporated, leaving the lindane us u white deposit, the mixture as a clear residue that was tenacious and slightly tacky, and the clilurinuti-d polyplicnyl us u hard, transparent residue. The panels were placed in a horizontal position and held at summer room temperature (70-100 p.) for 3 iitmilhs. Large nymph and adult roaches, Perijdanela amerieuim (L.), were used us test insects. After 2, 10. 30, 00, uml 00 days, 15 roaches were confined for 2 hums under each uf two petri dishes inverted over each test panel. The roaches Were thus exposed In the contact and fumigation uctiuu of the residues on the test panel. They were Hum transferred to ohscr-. vulion cages ami held for 4 days. ItnsuLTs.--The results of the tests are given in lidde I. The elfeclive life of a lindane residue, us measured by a 50 per centor heller killof roaehes on an aliiiuiiimil surface, is shown to he de|amdcut on the aimmiit of lindane used. Lindane residues of 50, I (Ml. and 200 mg. per square fool were elfeclive under summer conditions for less (hull 15, 30, noil (it) days, respectively. These were the periods during which the while deposit was visible. 'bit. .11. In m ri..,| iv.i . .n-atlv increased when Feltruary Wf>ii SCIENTIFIC NoTKrt Table 1.--Per cent mortality of roaches exposed to lindane and lindane-t residues of different ages on aluminum and masonite surfaces. Doeauk (Mu./Sq. Ft.) Clilorinated Lindane 1`olypheuyl 50 100 200 50 100 200 200 0 0 0 0 200 200 200 400 200 2 100 100 100 SO in 9H 35 1) Aluminum Suufacb Days 10 30 00 37 100 100 SO 07 KM) -- 0 0 30 7B 7B 70 03 71) 0 4 3 22 B0 B2 00 1)0 0 1)0 0 0 0 00 BO 00 1)5 0 Mash 2 72 100 100 31 too 100 -- -- 10 0 ll) 7H H 17 30 -- -- phenyl per square fool. Residues from 1IM) mg. of lindane plus 200 mg. of chlorinated polyplicny |m:i square foot increased the kill to B0 per cent, and residues from 200 mg. of lindane plus 200 mg. of cliluriimted (lolyphciiyl increased the kill lo 1)0 per cent. Tins residues remained transparent, tenacious, and only very slightly tacky. Roth lindane ala) lindaiic-cliloriiintcd-lKilyphenyl residues were much less elfeclive on the porous masonite surfaces. Residues of the chlorinated polyplicnyl alone Oil aluminum surfaces caused no mortality. Discussion.--These tests showed that the per sistence of lindane us a residue was greatly improved by incorporation into a film of chlorinated poly phenyl. The lindane in the iiiuiii body of tile film remained in solution and acted as n reservoir. As the liiuluiie evaporated from the surface it was continu ally renewed by a sLudy diffusion of lindane to this surface, liecuuse the limlane remained ill solution, there was no white powdery deposit, which often mars treated surfaces. The excellent spreading priqicrlics of the solutions and the incrLucss und tenacity nf the films suggest further uses in the field of entomolugy, mid they ure being investigated. LlTKllATUIlB ClTKU Block, S. S. 104B. Insecticidal surface coalings. Soup and Saint. Cheiu. 24(2): 1 SB-41, 17t. Lindquist, A. W., A. II. Madden, II. <*. Wilson, and E. F. Kuipling 11)45. DDT as a re sidual-type treatment for control of house flies. Jouit. Econ. Ent. 38: 257-Ul. Our first observations ii were made on May 5. 1`ra Knit, proved to be the ii insect. However there w parasitism and predatism serious. Tarnished plant 1> common. In only a single Ii. hugs, these were small uyi From May IS to 22 we n ill both the Cuimeetieiii County. The insect faun numbers of species mill in very uhimiluiit. Spiltlchiii and I.yyui hugs were conn side-ruble amount of leaf f vac of the clover leaf weevi many hud been killed 1>> clover root weevils were fu lepidnpterous larvae were as Kujcuu sp. On June 3 we inudc urn mid alfalfa fields ill the ( this time some uf the lid hug iiymplis were plcnti somewhat in nlniuduucc. abundant in must fields 1 having a relatively lui| alfalfa. A few lllelllhruci /eslinu, were observed fee alfalfa. Adults of the cln head caterpillar and ll found on the lluwcr liriu On June 5 some qiiunl the abundance nf spill seuteil below. Incidence of Forage Crop lVsls in .MiiBbUcliusctts und Seasonal History of the Meadow Spitllelmg1 1``. It. Sii.wv, A. I. IluilUNK and W. IhiVU Dining Hie past .scrismi we began some work on the f.,ragc crop pests of Massachusetts. Since no records uVi.il Ibl<- of till- .species of I lie insects or of (In ir FlKI.ll I'l.ANIri K.V IMINKIi #1 40 2 75 3 70 4 21) 1 r, -i ......... >!..oi. WATER PCB-SD0000039118