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- Publisher
- Oxford University Press
- Copyright
- © 1997 Entomological Society of America.
- eISSN
- 2155-9856
- DOI
- 10.1093/amt/22.1.75
- Publisher site
- See Article on Publisher Site
Abstract
Downloaded from https://academic.oup.com/amt/article-abstract/22/1/75/4639872 by DeepDyve user on 21 July 2020 D: CITRUS , NUTS , AND AVOCADOS Arthropod Management Tests, Vol. 22 75 ORANGE : Citrus sinensis: (L.) Osbeck 'Navel' J. G. Morse & A. A. Urena (18D) Citrus thrips: Scirtothrips citri (Moulton) Department of Entomology Predaceous mites: Euseius tularensis Congdon University of California Riverside, C A 92521 (909)787-581 4 SPEED-SPRAYER TRIALS FOR CITRUS THRIPS CONTROL, 1996: Insecticides were evaluated spring, 1996 in Field 41-4 2 at the Uni versity of California's Lindcove Field Station near Exeter, CA for control of citrus thrips. Pesticides were applied with an FMC CP-267 speed-sprayer pulled behind a tractor. Five treatments were compared against an untreated control using 200 gallons of water per acre and outside coverage (achieved by reducing fan speed). Th e field was divided into 12 plots; treatments were assigned to plots randomly and were replicated twice in each field; each plot was six rows wide and 5-8 trees long. Ten data trees were chosen from the center two rows of each plot, excluding the trees at the end of a row. Citrus thrips infestation due to first and second instar immatures was monitored after petal fall by examining 10 fruit randomly selected from each data tree (100 fruit per plot, 200 fruit per treatment in each field). Predaceous mite levels were monitored by counting the number of motile mites on 10 leaves picked from 0.5 m inside the canopy. Citrus thrips fruit scarring was evaluated in October, 1995 on all fruit on the exterior of data trees from knee to eye level. Scarring was rated as: (a) none, (b) slight (any citrus thrips scarring), or (c) severe (complete ring scar or extensive surface scarring at a level that would cause downgrading of fruit in a commercial operation). Approximately 5% severe scars are normally regarded as economic scarring levels. Petal fall in District I of Tulare County was declared on 26 April. In the week before petal fall and 6 weeks after petal fall, precipitation occured only on 15 May (0.12 inch) and 16 May (0.16) and mean weekly maximum temperatures were 63.9, 89.3, 83.9, 88.4, 78.9, 83.6, and 99.0°F, respectively. Citrus thrips population pressure in this field in 1995 was low resulting in 4.4% severe scarring on outside fruit in the untreated control. All of the treat ments resulted in less severe scarring than that observed in the untreated check. None of the treatments resulted in reductions in predaceous mite levels. FIELD 41-42, LINDCOVE FIELD STATION, 1996 Percent of outside fruit infested with citrus thrips % of outs de Treatment fruit scan red timing 5 Jun 24 Apr 1 May 8 May 15 May 22 May 29 May No. of \\ \ f«lt»*llC tVl (post trmt trmt trmt trmt trmt trmt trmt fruit Slight Severe Treatment Amount/acre + 13d + 27d + 34d examined Total petal fall) - 8d - Id + 6d + 20d NAF-085 4 SC 100 gm Al/ha pf + 6, pf 4.0a 20.0a 6.0b 2.0a 4.0ab 1.5b 1.0c 1,548 2.1b 0.4b 2.6b + 27 3.5ab Baythroid 2 EC 0.1 lbs AI pf + 6 1.0a 23.5a 0.0c 2.5a 0.5b 1.0b l.Obc 1,235 0.5b 4.0b Agri-Mek0.15E C 5 fl oz + 0.25% pf + 6, 5.0a 22.0a 8.0b 18.0a 7.0ab 9.5ab 6.0ab 1,533 4.8ab 0.6b 5.4ab + NR 415 Oil pf + 27 (1 st trmt) Veratran D + Sugar (2nd trmt) 12 lbs + 5 lbs Agri-Mek0.15E C lOflo z + 0.25% pf + 6, 5.5a 21.5a 7.0b 7.0a 7.5ab 9.5ab 6.0abc 1,313 6.1a 1.3b 7.4ab + NR 415 Oil pf + 27 (1st trmt) Veratran D + Sugar (2nd trmt) 12 lbs + 5 lbs Alert 2 SC 0.3 lbs AI pf + 6 7.0a 17.0a 0.0c 2.5a 1.5b 4.0b 4.5abc 1,119 5.5ab 1.9b 7.3ab Untreated Check 7.5a 23.5a 12.0a 28.0a 12.5a 17.0a 8.5a 1,699 8.6a 4.4a 13.0a — — Treatments are arranged in an ascending order of percent fruit showing severe scarring by citrus thrips at harvest. Means within a column followed by the same letter are not significantly different (P = 0.05, REGW Q multiple range test in SAS Version 6 after arcsine square-root transformation). Untransformed means are listed. Treatment timing was in relation to the date petal-fall was declared in District 1 of Tulare County (26 April): pf + 6 = 2 May; pf + 27 = 23 May. d = no.'of days; pf = petal fall date; trmt = treatment. Downloaded from https://academic.oup.com/amt/article-abstract/22/1/75/4639872 by DeepDyve user on 21 July 2020 76 Arthropod Management Tests, Vol. 22 D: CITRUS, NUTS, AND AVOCADOS FIELD 41-42, LINDCOVE FIELD STATION, 1996 (CONT.) Average no. motile predaceous mites per leaf Treatment timing 1 May 8 May 15 May 22 May 29 May 5 Jun Treatment (postpetal fall) trmt - 1 trmt + 6 trmt + 13 trmt + 20 trmt + 27 trmt + 34 pf + 6, pf + 27 2.3a 2.3a 2.5a 1.6a 1.5a 1.4a NAF-085 4 SC pf + 6 2.5a 1.4a 1.4a 0.8a 1.1a Baythroid 2 E C 0.3a Agri-Mek 0.15 EC + NR 415 Oil (1st trmt) pf + 6, pf + 27 1.9a 1.4a 1.7a 1.2a 1.1a 1.3a Veratran D + Sugar (2nd trmt) Agri-Mek 0.15 EC + NR 415 Oil (1st trmt) pf + 6, pf + 27 1.8a 1.4a 1.6a 0.9a 1.2a 0.9a Veratran D + Sugar (2nd trmt) Alert 2 SC pf + 6 2.4a 1.9a 2.3a 1.7a 1.7a 1.6a Untreated check 2.1a 2.5a 2.3a 1.6a 1.6a 1.4a Means within a column followed by the same letter are not significantly different (P = 0.05, REGW Q multiple range test in SAS version 6 after arcsine square-root transformation). Untransformed means are listed. Treatments are arranged in an ascending order of percent fruit showing severe scarring by citrus thrips at harvest. Treatment timing was in relation to the date petal-fall was declared in District I of Tulare County (26 Apr): pf + 6 = 2 May; pf + 27 = 23 May. d = no. of days; pf = petal-fall date; trmt = treatment. PECAN: Carya illinoensis (Wangenheim) K. Koch J. Victor French and Ben M . Jackson (19D) Blackmargined pecan aphid; Monellia caryella (Fitch) Texas A&M-Kingsville Citrus Center P.O.Bo x 1150 Weslaco, TX 78599-1150 (210) 968-2132 APHID CONTROL ON PECANS , 1996: Different rates of experimental BAS 300 1II were compared with MetaSystox-R for control of black- margined pecan aphid. Treatments were randomized and replicated 3 times on plots of 4- 5 trees each in a 12-yr-old pecan planting at a 30 X 30 ft spac ing. Sprays were applied 30 Jul using a Lockwood Hardie Super 40 air blast sprayer with nozzling, pressure and speed adjusted to apply 200 gpa. All live aphids were counted on 12 compoun d leaves randomly sampled per replicate (36 leaves per treatment) at 3 , 7 DA T and weekly thereafter. Aphid populations were building in all test plots when spraying was initiated. All treatments provided excellent knockdown of the blackmargined pecan aphid. The BAS-300 1II (0.25 and 0.50 lb Al/acre) treatments gave residual aphid control through 28 DAT , and was superior to the standard Meta- Systox-R treatment. No phytotoxicity was observed following any spray treatments. Mean no. aphids / leaf Rate DAT: lb AI/ Pre- Postspray Treatment acre spray + 3 + 7 + 14 +2 1 +2 8 mean BAS-300 11I75WP 0.10 11.11a 0.33b 0.33c 0.47b 1.89ab 3.22b 1.25b BAS-300 11I75WP 0.25 10.94a 0.19b 0.06c 0.19c 0.14c 0.14c 0.14c BAS-300 11I75WP 0.50 11.08a 0.03b 0.00c 0.03b 0.03c 0.17c 0.05c Metasystox-R SC 0.50 10.61a 0.75b 1.58b 0.94b 1.03bc 1.92b 1.24b Untreated check 12.67a 5.83a 3.44a 6.64a 3.03 8.75a 5.54a Means in a column not followed by a common letter are significantly different, as separated by Waller-Duncan K-Ratio Test {P s .001).
Journal
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 1997