Resource Information
     
Control of Thrips on Anthurium, Hawaii, 1992  
     

By: T.Y. Hata and A.H. Hara

Beaumont Agri Res Center, University of Hawaii-Manoa, 461 W. Lanikaula Street, Hilo, Hawaii 96720, Phone (808) 935-2885

HOST: Anthurium andraeanum Andre, cv. Ozaki
TARGETED PEST: Anthurium thrips: Chaetanaphothrips orchidii Moulton


EXPERIMENTAL PROCEDURE
Efficacy trials were conducted from 4 Nov 91 through 29 May 1992. Mature plants growing in 7.6 liter bags in volcanic cinder media under 80% polypropylene shade cloth were used in this study. Experimental plots measured 1.8 by 1.8 m with 36 plants per block, arranged in a randomized complete block (RCB) with four blocks. Seven biweekly applications of NTN 240F (33893) were applied from 5 Nov through 28 Jan to runoff using a compressed air sprayer with an 8004 Teejet nozzle at 276 KPa. Triton B-1956 was added to NTN 240F and the control at a rate of 0.23 ml per liter solution. NTN 0.5G (33893) was applied once on 4 Nov and watered immediately after treatment. Anthurium flowers were harvested biweekly at 3/4 to full maturity and observed for thrips injury characterized by distinct bleached streaks on the front and/or back of the spathe. Pre-treatment data was taken on 11 and 25 Oct. Biweekly data were pooled for analysis.

RESULTS
NTN 0.5G significantly reduced the percentage of flowers harvested with thrips injury for 5 months. There was no significant difference between NTN 240F and the control except in Mar. Anthurium thrips feed within the flower bud soon after the bud emerges from the leaf axial. Thrips injured flowers observed in Dec were the result of feeding injury to the bud which occurred in Nov. Phytotoxicity was not observed with both formulations of NTN.

Table 1. Percent of harvested anthurium flowers with thrips injury.

Pretrt.

AI Oct Nov Dec Jan Feb Mar April May Jun Jul Aug
NTN 0.5%G 0.06g/pot 77.3a 75.3a 50.0a 6.5a 1.8b* 2.3a** 14.9b* 24.7b* 34.0b** 48.4ab* 48.5a
NTN 240F 5.6g/100gal 83.6a 86.6a 71.0a 27.2a 25.8ab 32.8b 42.0ab 78.1a 90.0a 82.5a 40.6a
Control 81.5a 91.7a 61.0a 56.7a 62.3a 69.7c 74.2a 85.3a 74.3a 41.7b 21.6a


Percentages transformed to arcsine and subjected to Bartlett's test for homogeneity. Transformed data subjected to ANOVA P<0.05, P<0.01, *, **, respectively. Means followed by the same letter in a column are not significantly different by Scheffe's multiple comparison procedure.

PRODUCT INFORMATION
Product Name: NTN 33893 0.5%G
Manufacturer's Name: Miles Inc.
Address: P.O. Box 4913, 8400 Hawthorn Road Kansas City, MO 64120
Composition: imidacloprid 0.5%G

Product Name: NTN 33893 240F
Manufacturer's Name: Miles Inc.
Address: P.O. Box 4913, 8400 Hawthorn Road Kansas City, MO 64120
Composition: imidacloprid 2.0 lb active per gallon

PRECAUTIONARY STATEMENT
Use pesticides safely. Follow the pesticide label. Consult with the Cooperative Extension Service or the Hawai'i State Department of Agriculture for authorized special local need registrations or additional information. The user is responsible for the proper use, application, storage, and disposal of pesticides.

DISCLAIMER
Reference to a company or product name does not imply approval or recommendation of the product by the College of Tropical Agriculture and Human Resources, Cooperative Extension Service University of Hawaii, or the United State Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable. All materials should be used in accordance with label instructions or manufacturer's directions.