Downing, R. S.

English

Journal of the Entomological Society of British Columbia

ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC. (1950) . VOL. 47. JULY 15 . 195 1 ACARICIDE TRIALS IN BRITISH COLUMBIA ORCHARDS, 19501 R. S. DOWNING2 Dominion Entomological Laboratory. Summerland . B . C. Although the two acaricides parathion and monoethanolamine dinitro-o-cyclo-hexylphenolate. presently being recom-mended for British Columbia orchards. are reasonably effective, each has short-comings that mark it for replacement as soon as possible. Parathion. first recom-mended for the control of orchard mites in 1949, has a serious disadvantage in its high toxicity to mammals. Further-more. it lacks specificity and it is not sufficiently effective against the Willam-ette mite, T etranychus flauus Ewing . Monoethanolamine dinitro-o-cyclohex-ylphenolate. commonly called mono-DNP by British Columbia growers. may cause some foliage injury. Although it seems to be a selective acaricide, largely innocuous to parasites and insect pred-ators , it can no longer be used generally because most of the spraying is done by automatic concentrate sprayers and these machines increase phytotoxic effects. A second weakness of mono-DNP is its relatively weak acaricidal effect in cool weather. Hence it cannot be used in the " pink ", application. which, in British Columbia. is the most favoured spray against the E uropean red mite. M etate-tranychus ulmi (Koch) . Furthermore, mono-DNP is sometimes injurious to the tender young foliage of the early part of the season even when applied by conventional spray gun . During the season of 195 0 . field ex-periments were undertaken with prom-ising new acaricides against the most troublesome orchard mites in the Okan-agan Valley of British Columbia. The new acaricides and their performance III the orchard are discussed herewith. Acaricides under Trial' C-I006 (50 per cent p-chlorophenyl p-chlorobenzene sulphona te; Dow 1 ( \ ,ntributi oll r\o. 2i4(j, DiYi s ion of Elltomolog·y . Sc·ielltc Sen-ict! . Depart ment of .-\ g ri c'uhn re. Ottawa. ( 'aJlada. :; The t erm pink is u~ed to dell ote t.ha t peri od of d e-n·lopment wh en the Moral buds have just se para ted ill the (: lu:,t er and befol'c the first Hower ha s ope ned . .. An :J.cari r.idt!,"; were used ill t he wettable powd er fOI'IIl. Ch~mical CO.) .-This compound has a low human toxicity rating but a high phytotoxicity rating. Applied to apples in the pink stage at a concentration of 1. 5 pounds". it caused severe foliage injury to Mcintosh . D elicious, New-town and Winesap. When applied in August at 1 pound. it injured Newtown but not Delicious and Winesap. EPN 300 (27 per cent ethyl p-nitro-phen yl thionobenzene phosphonate ; E. 1. DuPont Co.) .-Although EPN 300 has a lower human toxicity rating than parathion, it is. nevertheless. very poi -sonous. When applied to apple in the pink stage at 0.75 pounds. it injured foliage of Mcintosh but not of D eli-cious, Newtown or Winesap. KARATHANE (25 per cent dinitro capryl phenyl crotonate; Rohm and Haas Co.) .- As a pink application to apple at 1.5 pounds, this dinitro com-pound has not caused foliage injury to Delicious . Mcintosh , Winesap . Jona-than or Newtown . but applied to New-town in August at the same concentra-tion it caused a slight amount of foliage IllJury. R-242 (50 per cent p-chlorophenyl phenyl sulphone; Stauffer Chemical Co.). - This compound has a low human toxicity rating and as a pink or summer application to apple, at 2 pounds. has not caused injury to Deli -cious, Mcintosh . Newtown. Winesap or Jonathan. ARAMITE ( 15 per cent beta-chlor -oethyl beta- (p-tertiary butylphenoxy ) alpha methyl ethyl sulphite; Naugatuck Chemicals) .-Aramite is rated low in toxicity to hu mans ; and as a pink or summer application , at 2 pounds. has not injured Delicious. Mcintosh, New-town, Winesap or Jonathan. Effects of Acaricides on Orchard Mites Europea n Red Mite. Metatetranychus ulmi (Koch ) .-Since the introduction of DDT, this mite has been one of the ;J All cOIJ("e ntra t ioll s are for 100 imperial gallo l1 .:;; (approximately l:.! O U.~. gallons). 2 ENTOMOLOGICAL SOc. 01" BRITI SH COLUMBIA, PROC. (1950). VOL. 47 , JULY 15. 1951 most troublesome orchard pests in the Okanagan Valley. Experimental work carried out by officers of the Summer-land laboratory has shown that para-thion applied at the pink stage of apple development is highly effective against the red mite. In 1950. several of the neWer acaricides were applied at that stage for comparison with parathion. No further acaricide applications were made until the first week in September . when acaricides had to be applied for the control of the two-spotted spider mite. Mite populations were sampled two weeks. one month , and two months after spraying. The results from three orchards are averaged and summarized in Table 1. T}\BLE I Effec ts of pink application of acaricides on the European red mite; materials applied by a conven tion al hand-gun sprayer. Acaricide C - I006 (50%) Parathion ( J 5 %) EPN 300 (27 % ) R-242 (50 % ) Karathanc (25%) C h eck-no treatment ________ _ _ Two-Spotted Spider Mite. Tetrany-chus bimaculatus Harvey ; and Pacific Mite, T etranychus pacificus McG. -These mites are considered together be-cause they generaIly coexisted in 1950 and occurred together in the trial plots. The tw o-spotted spider mite was not a major pest of Okanagan Valley or-chards ur.til August . 1950, when it be-came most troublesome and widespread. Amount per 100 gal. 1.5 lb. 1.0 lb. 0 .7 5 lb. 1.5 lb. 1.5 lb. Average number of mites per leaf during season 0 . 17 0.34 0.40 0.44 1.8 8 6.74 The Pacific mite was also more abun-dallt than for several years past. In fact, as pests these two mites replaced the European red mite in importance. An experiment was carried out to compare sevrral new acaricides with parath ion for control of these two spec ies of mites on D elicious. Newtown. Winesap, Jonathan and YeIIow Trans-parent apple trees. The results arc sum -marized in Table II. TABLE II EfTects of a(aricid es on the two-spotted spider mite and the Pacific mite; materials applied by a conventional hand-gun sprayer in Au gust, 195 0. A verage mites per leaf Before spraying After spraying Acaricide Arami te (15 % ) Amount per 100 gal. 2 lb. Aug. 29 Sept. 8 Sept. 13 13.7 0.2 0.4 Parathion (J 5 %) ___ __ _____ _________ _ C - 1006 (50 % ) _ __________ _ R-242 (50 %) _ Karathane (25',70) ________ _ C heck-no treatment ______ _ lb. lb. 2 lb. 1.5 lb. \Villamette Mite, Tetranychus flauus Ew ing.- This pest , first reported in the Okanagan Valley in September. 1949, at Summerland, has been found since then at Oliver. Penticton, and Kelowna. Earl y in 1950. before the mite had an opportunity to do a great deal of damage. a few materials. some of which were available to the grower. were ap-22.3 0.3 0 .6 3 9.4 30.3 46.4 8.0 1.8 2.3 3. 4 13.4 0.5 2.9 3.3 [ 8.5 plied to single limbs of Delicious apple trees in a preliminary experiment. Be-fore and after the materials had been applied. 10 leaves were picked at random from each of the treated limbs. The leaves were examined for mites under a mIcroscope. Results are summarized in Table III. ENTOMOLOGICAL SOc. OF B RITISH C OLUMBIA. PROC. ( 195 0 ) , VOL. 4 7. JL'LY 15. 1951 3 TA BLE III Effects of aca ricides on the \Villamette m ite. materi als app lied by a com'entional hand -gu n spraver in Jul y. 19 50. Average number mites per lea f Before spraying After spraying Material Amount per 100 gal. July 5 July 10 Parathion (I 5 % ) __ ____ ____ _________ ___ _ D initro-o-cyclohexy\ phenol (40 %) _____ _ Pa rathion ( 15 %) ____ _ ___ . ________ _ Stove oil G __________________ __ _ ______ __ ___ _ Pa rathion (15 % ) __________ ______ ________________ _ D initro- o- cyd ohex yl phenol (40% ) 7 ___ _ _ EPN 300 (27 % ) __ ________ . ________ _ C heck-Water _______________ _________ . . r. :l 4 R.S .D. Vi s. 100° F., over 75% U.ll.. -; DN-Dry Mix No . 1. Dow Chemical Co., Toronto, On t o As an ou tcome of this experiment . a mi xture of 15 per cent parathion , 8 pounds per acre, and 40 per cent dinitro-o-cyclohexy lphenoL 2 pounds per acre, was applied to Delicious apple trees by an au to mat ic concentra te spraye r. Excellen t con trol w as achieved : the W ill amette mi te remained at a very low level for seven weeks. Spray injury was confined to sucker growth . In an other orchard heavily infested with the W illam ettc mite. two pa rathion-dinitrc mixtures were applied w ith an auto-matic concen t rate sprayer . In one plo t pa rathi on was ma intai ned at 8 poun ds I lb . 5 oz. I lb. I q t. 2 lb. 5 oz. 1.5 lb. 2 .3 0 5.3 0 14 . 9 0. 2 9.2 0 .2 19. 1 0 .5 5.4 10 . 1 per acre and in a second plo t it was re-d uced to 3 pounds per ac re. There was littl e diffe rence in degree of control between the two pl ots. In an other experim en t three of the new aca ricides were compared with parathion alone. Four t rees were sam-pled in each plo t of 15 to 20 t rees. Samples fro m each tree consisted of 100 leaves, and an estimation of effect iveness was made fro m the number of infested leaves. T he toxican ts were applied w ith an automatic concentrate sprayer in A ugust, 1950 . R esul ts are summar -ized in Ta ble IV . TABLE IV E ffect s o f a(ar icides o n the \Vi llamette mite: mate rials applied by an au to matic con cen t ra te sp rayer in Au gust. 195 0 . Percentage infested leaves Before spraying After spraying Acarcide A ramite (1 5 % ) Ka rathane (25 o/c) Amount p e r acre J 2 lb. Aug. 24 Aug. 31 S ept. 1 84 . 2 1.7 0 R-2 4 2 (50'/0) ___ _ Pa rat hion ( 15 % ) __ C heck-no treatment _ Summary 12 lb . 12 lb . 8 lb. (I) Du rin g 1950, five new, promis-ing acaricides were compared with par-athion for control of var ious mites in orchards of British Columbia. These were: C-I0 06 (5 0 per cen t p-chlorophenyl p-chl orobenzene sulphonate) . EPN 300 (27 per cen t eth yl p-nitro -phenyl thionoben zene phospho-nate) . KARAT H ANE ( 25 per cent din itro capryl phenyl cro to nate) . 97. 5 0.5 0.2 99.2 39 .0 41.7 90.S 60 .2 6 1.5 99.2 96 2 97.0 R-2 42 ( 50 per cent p- chlorophenyl phenyl sulpbone). ARA MITE ( j 5 per cent beta -chl oroeth yl beta- (p -tertiar y butyl phenoxy) alpha methyl eth yl sul-phite) . (2) C- I006 has a low human tox -icity ratin g but a rather high phytotox -ici t y rating. At 1. 5 pound s per 100 ga ll ons, it was the most effective acari -cide used in the pink applicat ion for control of the Europea n red mite. When used as a summer spray at 1 pou nd. it 4 ENTOMOLOGICAL SOc. OF BRITISH COLUMBIA, PROC. (1950), VOL. 47, JULY 15, 1951 gave excellent control of the two-spotted spider mite and the Pacific mite. (3) EPN 300 has a high human toxicity rating and a medium phyto-toxicity rating. When applied in the pink stage at 0 .75 pounds it gave good control of the European red mite al-though it w'as somewhat inferior to I pound of parathion . At 1.5 pounds it gave considerably better control of the Willamette mite than I pound of para-thion . C 4) KARA THANE applied at the rate of 1.5 pounds was not so effective as 1 pound of 15 per cent parathion when used as a pink application for control of the European red mite , or when used in summer applications for control of the two-spotted spider mite and the Pacific mite, When applied in the summer by an automatic sprayer at 12 pounds per acre. however. it gave excellent control of the Willamette mite. Although it caused a very slight amount of damage to Newtow'n apple trees in August . it has a low phytotoxicity rating. (5) R-242 has a low human toxicity rating and a low phytotoxicity rating. At 1. 5 pounds. it was slight! y less effec-tive than 1 pound of parathion (15 per cent ) when used as a pink application for control of the European red mite, When used in the summer at 2 pounds it was not so effective as 1 pound of parathion for control of the two-spotted spider mite and the Pacific mite. When used at 12 pounds per acre in a concen-trate sprayer. however. it was slightly more effective against the Willamette mite than 8 pounds of parathion. (6) ARAMITE has a low human toxicity rating and low phytotoxicity rating . When applied in the summer at 2 pounds, it gave excellent control of the two-spotted spider mite and the Pacific mite. Also. when applied by a concentrate sprayer at 12 pounds per acre. it gave excellent control of the Willamette mite. NOTES ON THE SPRING ACTIVITY OF THE ROCKY MOUNTAIN WOOD TICK, DERMACENTOR ANDERSONI STILES (ACARINI: IXODIAE)l J. D, GREGSON L ivestoc k In sect Labo rato ry , Kamloops, B. C. One of the remarkable features in the dry -belt they disappea r regularly in life-cycle of the Rocky Mountain wood May, regardless of how moist or cool tick. Dermacentor andersoni Stiles. in the preva iling atmospheric conditions British Columbia is the annual appear- are. It is suggested that some form of ance of adults at the beginning of spring diapause must take effect. releasing its and their regular disappearance about hold only after another winter has the middl e of May. Such seasonal passed. periodicity is natural for most insec ts , In the Interior of British Columbia of which the adult stage is generally of the Rocky Mountain wood tick is dis -short duration. However. ticks usually tributed throughout the greater part of live longer than insec ts . and it would the dry bunch-grass open-land, Its be expected that adults of the Rocky peak abundance may vary. depending on Mountain w'ood tick, which are here- the locality . from sparse populations to with shown to be capable of living for heav y concentrations. The latter occur at least 1 year. w hich continue to be in scattered parts of the Province where active as long as the weather remained host and climatic conditions are appar-favourable. Such is not the case. how- ently particularly ideal for tick develop-ever. and though in Alberta and in the ment and survival. One such site is at damper regions of British Columbia Rayleigh. 10 miles north of Kamloops. adults of this species may be active as B , C. where there is an extensive talus late as June, in the British Columbia slope backed by a rocky bluff 200 feet 1 Contribution \"0. 271 i. nh' i~ioIl of Entomology. Seiellf'e Sen'ice, Department of AgIicu1tul'e, Otta wa, ('<tHada. high. The narrow belt of vegetation at the base of the cliff. besides harbour-ing a variety of rodent life. seems regu-

Acaricide trials in British Columbia orchards, 1950

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Acaricide trials in British Columbia orchards, 1950

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Journal of the Entomological Society of British Columbia