Resource Information
     
Control of Insect Pests on Red Ginger, Hawaii, 1990  
     

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: Red Ginger: Alpina purpurata (Vieill.) K. Schum.
TARGETED PESTS: Banana aphid: Pentalonia nigronervosa Coquerel, Cotton aphid: Aphis gossypii Glover , Citris mealybug:
Planococcus citri (Risso), Obscure mealybug: Pseudococcus affinis(Maskell) , Long-tailed mealybug: Pseudococcus longispinus (Targioni-Tozzetti), An ant: Technomyrmex albipes (Fr. Smith)


EXPERIMENTAL PROCEDURE
Efficacy trials were conducted from 7 Jul to 27 Aug 1990 in field plantings of red ginger. Treatments were arranged in a RCB with 4 replicates per treatment. Insecticide sprays were applied to runoff using a compressed air sprayer with an 8004 Teejet nozzle at 40 psi. Triton B-1956 was added to both foliar applications and the control at a rate of 3.0 fl oz/100 gal. Empire 20MEC was applied as a barrier treatment within the ginger stalks and a 2 ft radius around the planting using the same equipment as foliar applications. Di-syston was applied with a shake type dispenser and immediately worked into the media with a hoe and watered thoroughly. Insecticides were applied at two week intervals for a total of 3 applications except for Di-Syston which was applied once. Water was sprayed in control plots. Fifteen flowers were randomly sampled from each treatment at 3/4 maturity and observed for all insect pests under a dissecting microscope. Three species of mealybugs were pooled for analysis.

RESULTS
Di-Syston 15G and Pageant DF significantly reduced ants, banana aphids and mealybugs. Empire 20MEC totally eliminated ants and mealybugs; however, banana aphids although numerically reduced, were not significantly different from the control. Orthene 75SP significantly reduced banana aphids, but was not effective against ants. Mealybugs were also numerically reduced but not significant. All tested insecticides were not effective against cotton aphids. In addition, phytotoxicity in Di-Syston treated plots was characterized by necrotic spots covering the entire leaf.

Treatment AI/100gal   Ants Banana aphid Cotton aphid Mealybug  
    Before* After Before After Before After Before After
Empire20MEC 0.5 lb 12.4b 0.0 38.1a 48.4ab 1.1a 3.1a 6.6a 0.0
Orthene 75SP 0.25 lb 28.3a 24.9a 35.0a 33.4b 16.6a 28.8a 12.7a 7.6ab
Pageant DF 0.5 lb 7.3b 6.7b 5.1a 7.6b 0.5a 1.7a 7.9a 1.4b
Di-Syston15G 19.4 lb/ac 12.3b 0.9b 2.7a 0.0 1.9a 0.7a 4.9a 0.3b
Control   10.7b 30.1a 103.4a 88.8a 5.9a 5.0a 8.1a 17.7a


Data transformed to x+1 and subjected to anova (P < 0.05). Means followed by the same letter in a column are not significantly different by Waller-Duncan K-ratio T test. Mealybugs significant at P < 0.1.
*Number of insects observed before and after treatment.

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.