Resource Information

     
Control of Orchid Weevils on Dendrobium, Hawaii, 1990  
     

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

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

HOST: Dendrobium Orchid: Dendrobium Jaquelyn Thomas
TARGETED PEST: Orchid weevil: Orchidophilus aterrimus (Waterhouse)


EXPERIMENTAL PROCEDURE
Bioassay tests were conducted from 3 May through 9 May 1991 at the University of Hawaii Waiakea Experiment Station. Established plants growing in 1/2" crushed basalt rock were used in this study. Insecticides were applied to runoff using a compressed CO2 sprayer with a 8004 Teejet nozzle at 276 KPa. Three days after treatment, 16 leaves per treatment, 4 leaves per rep, were excised and placed into 12.0 x 10.5 cm unwaxed paper containers. Ten orchid weevils collected on bamboo orchids Arundina graminifolia (D. Don) Hochr. was added to each container and covered with organdy. Mortality and the number of feeding marks were assessed 1, 2, and 3 days after treatment (DAT).

RESULTS
All treatments had significantly higher mortality than the control 1 DAT. Combinations of Orthene/Tame were most effective followed by Tame CC14690, Tame CC17228 and Orthene, respectively. There was no significant difference among both Tame formulations and Tame/Orthene combinations. At 2 DAT, there were no significant differences among Tame/Orthene combinations, Tame CC14690 and Orthene. At 3 DAT, there was no significant difference among all insecticide treatments. Six hours after exposure, orchid weevils exposed to both formulations of Tame were observed crawling on the top of the container. This behavior was not observed in any of the other treatments. In addition, 3 DAT leaves treated with both Tame formulations and Tame/Orthene combinations had less feeding injury as compared to Orthene and the control. Apparently, Tame had a repelling action on the orchid weevil.

% Mortality

Treatment lbs (AI)/100 gal 1 DAT Injury 2 DAT Injury 3 DAT Injury
         
Orthene 75SP 0.25 60.0b 6.5ab 87.5ab 7.3b 97.5a 9.8b
Tame CC17228 0.20 72.5ab 0.0b 85.0b 0.0b 97.5a 0.0c
Tame CC14690 0.20 87.5ab 0.3b 100.0a 0.3b 100.0a 0.3c
Tame CC17228/Orthene 0.20/0.25 97.5a 0.3b 100.0a 0.3b 100.0a 0.3c
Tame CC14690/Orthene 0.20/0.25 92.5a 0.0b 100.0a 0.0b 100.0a 0.0c
Control - 0.0c 8.3a 0.0c 26.8a 10.0b 37.5a

Percentages subjected to ANOVA (P < 0.01). Mean separation by Bonferroni t tests.

PRODUCT INFORMATION

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.

Product Name: Tame 2.4EC CC14690
Manufacturer's Name: Valent U.S.A. Corporation
Address: 1333 N0. California St., Walnut Creek, CA 94598
Composition: fenpropathrin 2.4 lb active per gallon

Product Name: Tame 2.4EC CC17228
Manufacturer's Name: Valent U.S.A. Corporation
Address: 1333 N0. California St., Walnut Creek, CA 94598
Composition: fenpropathrin 2.4 lb active per gallon

Product Name: Orthene 75SP
Manufacturer's Name: Valent U.S.A. Corporation
Address: 1333 N0. California St., Walnut Creek, CA 94598
Composition: acephate 75.0%