Journal of Taiwan Agricultural Research

Author:Yu-Bing Huang, Ching-Hua Kao*, Ming-Yao Chiang, Edward Y. Cheng, and Mu-Chuan Lee

Abstract:

    Citrus is a very important fruit crop in Taiwan with an acreage of more than 32,000 ha, however, the threat from the oriental fruit fly (Bactrocera dorsalis Hendel, OFF) is a constant problem.  Current OFF control program started in 1959 for the purpose of protecting the citrus for export, and control of OFF has been on the priority list. Following the success of area-wide control of OFF in sugar apple (in Taitung) and wax apple (in Juan-Nan), practical test on citrus becomes urgent.  Da-Lin Township of Chia-Yi County was selected because citrus is the only fruit crop grown in this area.  With the corporation of growers from Da-Lin, an area-wide OFF control program was launched in 2005, which included measures such as geographic and agricultural information gathering. OFF population monitoring, male annihilation by methyl eugenol bait and protein food bait to kill and lure female OFF.  The 400 ha test area covering 120 ha citrus orchards started the control program since early June of 2005, and the OFF population was greatly reduced to less than one fly per trap per day.  No hot spots were found due to alternative hosts of OFF was rarely existed in this area.  The citrus production in Da-Lin was not subjected to bagging as it was done to the the wax apple or sugar apple.  As such, the OFF damage rate was assessed directly.  By sampling the citrus fruits from three orchards, 0.35% damage rate was obtained.  Another benefit of this program was no insecticide spray needed.  Reduction of OFF damage minimized the cost of insecticide spray and residual problem, which also improved the quality of citrus fruits and the environment in which farmers are routinely working.  For two consecutive years, the saving of insecticide spray was estimated at 1.4 million NT dollars (US$ 44,343) per year.  It is also observed that economic motivation and farmer education were essential to a successful area-wide control program. The small acreage model in citrus is of vital importance because there are a number of similar production areas like Da-Lin in Taiwan, and field demonstration on area-wide OFF control to other citrus growers will be initiated in the near future.

Key words:Area-wide control, Bactrocera dorsalis, Citrus, Small acreage model

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