Resource Information

Postharvest Insecticidal Dips for Control of Thrips on Dendrobium, 1992  

By: T. Y. Hata, A. H. Hara and Ben 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 cv. Uniwai
TARGETED PEST: Frankliniella occidentalis (Pergande)

Postharvest insecticidal dips were evaluated in Apr. 1992 at the University of Hawaii Waiakea Experiment Station in Hilo, Hawaii. Flowers were harvested from a commercial dendrobium farm in Kailua-Kona, Hawaii. Dendrobium plants were well established growing in 1/2" crushed basalt rock under 30% polypropylene shade using standard cultural practices. Prior to harvest inflorescences were visually inspected for the presence of thrips. Only infested inflorescences were selected for testing. Treatments consisted of 3 replicates, with 5 inflorescences per replicate. Each replicate was dipped floral end first into 19 liter buckets containing the insecticide solutions. Control inflorescences were dipped in water. Inflorescences were submerged for 3 minutes, and gently agitated 10 times at emergence, at 1.5 minutes and again before removal for a total of 30 times. After dipping, inflorescences were placed into buckets and allowed to air dry. Twenty-four hours after treatment, blossoms were removed from the inflorescences, counted, and placed in berlese funnels heated with a 60 watt incandescent light bulb. Thrips were collected in a 8:2:1:1 solution of ethanol, distilled H2O, acetic acid and glycerin. The number of nymphs and adults were counted. Because the number of blossoms per inflorescences varied, thrips counts were adjusted to the number of thrips per blossom by dividing the total number of thrips recovered by the total number of blossoms.

All treatments had significantly less thrips per blossom than the control. Dursban 4E and Avid 0.15EC were most effective followed by the Mavrik Aquaflow/Incite combination, Pageant DF and Mavrik Aquaflow. There was no significant difference among Dursban 4E, Avid 0.15EC, Mavrik Aquaflow/Incite and Pageant DF. Dursban 4E treated flowers had a detectable odor after treatment.

Study 1

Treatment AI (g/liter) Thrips/blossom
Mavrik Aquaflow 0.1 0.50b
Pageant DF 0.7 0.21bc
Mavrik/Incite 0.1/0.6 0.16bc
Avid 0.15EC 0.6 0.11c
Dursban 4E 0.01 0.09c
Control - 1.10a

Data transformed to log10(x+1) and subjected to ANOVA (P < 0.01). Means followed by the different letters in a column are significantly different by Waller-Duncan K-Ratio T test.

"Hawai'i pesticide law prohibits the use of many insecticides as dips or drenches. Pesticide labels which prohibit dip usage or state the amount of product to be used per acre cannot be legally used as dips. Used dip solutions should be disposed by applying to approved crops or site in accordance with all label directions. Contact the Hawaii Department of Agriculture, Pesticide Branch if in doubt about legal use and proper disposal of insecticide dip solutions."

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: Mavrik Aquaflow
Manufacturer's Name: Sandoz Crop Protection Corp.
Address: 1300 E. Touhy Ave., Des Plaines, IL 60018
Composition: fluvalinate 2.0 lb active per gallon

Product Name: Pageant DF
Manufacturer's Name: Dow Chemical U.S.A.
Address: P.O. Box 1706, Midland, MI 48640
Composition: chlorpyrifos 50%

Product Name: Incite
Manufacturer's Name: Loveland Industries Inc.
Address: P.O. Box 1289, Greeley, CO 80632
Composition: Piperonyl Butoxide 8.0 lb active per gallon

Product Name: Avid 0.15EC
Manufacturer's Name: MSD Ag Vet.
Address: P.O. Box 2000, Rahway, NJ 07065
Composition: avermectin B1 0.15 lb active per gallon

Product Name: Dursban 4E
Manufacturer's Name: Dow Chemical U.S.A.
Address: P.O. Box 1706, Midland, MI 48640
Composition: chlorpyrifos 4.0 lb active per gallon