行政院農業委員會台南區農業改良場  研究彙報第15號

水稻縱捲葉蟲之發生及防治適期研究

顏福成

摘  要

一、水稻縱捲葉蟲,目前在台南地區為主要水稻害蟲之一。於第二期作若逢大發生而不加以防治者,產量損失達18∼24%。

二、本蟲在台南地區之發生量,依地區不同,以曾文、新營、嘉義、虎尾、斗六等小區為多,海岸地帶北門、東石、北港等小區較少。

三、本蟲周年發生消長,依地區而不同,惟均以第二期作發生為多,第一期作較少。區內11小區之周年發生消長可分為三種型態。

(一)早發型:包括曾文、新營、嘉義、斗六、虎尾等小區。自第一期作開始多量發生為害,至第二期作更嚴重。發生量較他型為多。

(二)晚發型:包括新豐、新化、中埔、東石、北港等小區。第一期作發生量少,對水稻為害輕微。只於第二期作為害較嚴重。

(三)中間型:包括北門小區及安南區。自6月下旬∼7月上旬開始發生,為害中間作水稻至10月下旬為止。

四、本蟲為害確實對稻穀產量有影響。將被害葉率控制於2%時損失有1.5∼1.7%,5%時2.8∼3.7%,10%時4.9∼6.6%,15%時9.2∼15.7%。

五、本蟲之防治,在被害葉率約2%(每叢約1葉時)最為經濟。5%時(每叢約2.5葉)次之。不可超過10%以後始噴藥。


Studies on the Population Dynamic and Optimal Control Time of Rice Leaf Roller

Yen Fu-Cheng

Summary

1. The rice leaf roller (Cnaphalocrocis medinalis Guenee) has become one of the main insect pests on rice in Chia-Nan area recently.  And 18~24% of yield loss was caused by the pest in second rice crop.

2. Different area prepared the different population density.  Where Tseng-Wen, Hsing-Ing, Chia-Yi, Fu-Wei and Tou-Liu prepared the highest population.  The population of pests in the costal area of this island, such as Pei-Men, Tong-Shih and Pei-Kang etc, generally was lower than other area.

3. The annual population fluctuation was varied in different area.  According to the 11-area investigation in Tainan District, the population dynamic was divided into 3 types.

A. Early type: The pest occurred and attacked in both the first rice crop and the second rice crop but it caused much more serious damage in the second rice crop than in the first rice crop.  The area included Tseng-Wen, Hsing-Ing, Chia-Yi, Tou-Liu and Fu-Wei, etc.

B. Late type: The pest occurred mainly in second rice crop and caused more damage.  The area included Hsing-Fung, Hsing-Hwa, Chung-Pu, Tong-Shih and Pei-Kang, etc.

C. Medium type: The pest mainly attacked on the inter mediate crop of rice.  The occurring season was from late June to mid October.  The area included Pei-Men and Tainan city.

4. It caused 1.5~1.7, 2.8~3.7, 4.9~6.6 and 9~15.7% of yield loss when the pest rolled 2%, 5% and 15% leaves, respectively.

5.It is much more economic to control the pest at the time 2% of leaves rolled by the pest, and 5% of leaves rolled comes to the next.  But it must be rapid more attention to the right time for control.



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