Resource Information

Insecticidal Trials Against Thrips on Orchids, Hawaii, 1994  

By: T. Y. Hata, A. H. Hara and B.K.S. Hu

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

HOST: Dendrobium Orchid: Dendrobium 'Uniwai Pearl'
TARGETED PEST: Dichromothrips corbetti

Insecticides were evaluated for efficacy from 8 Dec through 15 Dec 1994 at the University of Hawaii Waiakea Experiment Station in Hilo, Hawaii. Plants (approximately 6.5 ft in height) growing in basalt rock under 6 mil. clear FVG 3HLFI polyethylene film covering were used in this study. Experimental plots were arranged in a randomized complete block (RCB) with 3 blocks, 30 plants per block. A spreader-sticker (Ad-here, J.R. Simplot, Lanthrop, CA) was added to all treatments, including the control, at a rate of 5 fl. oz. per 100 gals. The control was sprayed with water. Insecticides were applied once at approximately 200 gpa using a backpack sprayer (Solo, Newport News, VA) equipped with an 8004 Teejet nozzle at 40 psi. Treatment efficacy was evaluated by randomly harvesting 30 blossoms from each block. Thrips were extracted from the blossoms with Berlese funnels heated with a 60 watt incandescent light bulb and collected in an 8:2:1:1 solution of ethanol, distilled H2O, acetic acid and glycerin. The number of nymphs and adults were pooled for analysis. Data were transformed to log10 (x+1) and analyzed by analysis of variance (ANOVA).

All insecticide treatments significantly reduced thrips. There was no significant difference among insecticides.

Treatment AI/100 gal Before After
Talstar F   35.7a 1.5b
Dursban 50W   32.1a 0.0b
Malathion 57EL   17.1a 0.8b
Control -- 20.9a 7.8a

Means followed by the same letters in a column are not significantly different by Waller Duncan K ratio t test, K = 100.


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.

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.

Product Name: Dursban 50W
Manufacturer’s Name: DowElanco
Address: 9002 Purdue Rd., Indianapolis, IN 46268-1189
Composition: chlorpyrifos 50%

Product Name: Malathion 57EL
Manufacturer’s Name: Hacco Inc.
Address: P.O. Box 7190, Madison, WI 53707
Composition: malathion 5.0 lb active per gallon

Product Name: Talstar Flowable
Manufacturer’s Name: FMC Corp.
Address: 2000 Market Street, Philadelphia, PA 19103
Composition: bifenthrin 0.67 lb active per gallon