一、計畫緣起
墾丁國家公園擁有豐富的陸蟹生態資源，然近年發現影響陸蟹生存的黃狂蟻 (Anoplolepis gracilipes) 已進入陸蟹棲地並形成更具威脅性超級群落，對墾丁陸蟹族群數量造成莫大的影響。「106年度墾丁國家公園黃狂蟻入侵狀況調查與防治策略研擬」、「106年度港口地區黃狂蟻調查」、「107年度墾丁國家公園黃狂蟻監測與防治計畫」的調查結果，顯示在墾丁國家公園園區內主要的陸蟹分布熱區 (香蕉灣、砂島及港口) 有較高密度黃狂蟻族群數量的分布，且已經形成的超級群落 (supercolony) 現象。「109年度墾丁國家公園黃狂蟻人工誘引盒防治計畫」使用黃狂蟻人工蟻巢誘引盒，在香蕉灣、砂島、港口樣區誘集到並清除約500隻蟻后和46萬隻工蟻。「110年墾丁國家公園黃狂蟻防治計畫」 針對香蕉灣與港口海岸林進行餌劑防治施撒作業，並以液態餌站與人工蟻巢誘引盒方法來監控防治樣區內黃狂蟻的族群動態，總共誘集到並清除約1,150隻蟻后和約25萬隻工蟻。
二、方法及過程
本年度計畫擴大香蕉灣和港口樣區的誘餌防治範圍為各2公頃，於110年度在香蕉灣和港口樣區的黃狂蟻聚集處執行6次的液態與固態型餌劑防治作業；並延續110年度的黃狂蟻誘引盒防治計畫，在香蕉灣設置40個、港口20個及砂島10個 (無餌劑作業控制對照組)，共70個人工誘引盒進行黃狂蟻族群蟻巢密度監控，誘引盒放置位置參考「110年度墾丁國家公園黃狂蟻防治監計畫」所設立的調查樣點，並於上述三個熱點樣區各香蕉灣設置20個、港口10個及砂島10個液態餌站監測點，於每個月更換誘引盒並於監測點執行誘集法的螞蟻調查以監控黃狂蟻族群動態變化。並評估長期墾丁國家公園內黃狂蟻族群的防治策略及建議。
三、重要發現
本年度1月至12月在三個樣區中共累積217盒蟻巢、蟻后1,962隻，工蟻約35萬隻，其中以港口的黃狂蟻蟻巢數、工蟻數量最多，蟻后數為香蕉灣最多；111年誘引到的黃狂蟻數量較109和110年度高。經過液態餌劑和生長調節劑防治的香蕉灣樣區中，工蟻和蟻后數目有明顯下降趨勢。港口樣區只有工蟻個體數有下降，而蟻后和蟻巢數無太大影響。於110年與111年均有進行液態餌劑與昆蟲生長調節劑型餌劑防治的月份 (3月至8月)中，可以看出整體工蟻數與蟻巢數蟻巢比例都有比109年有逐漸下降的趨勢，且蟻后有逐漸集中的現象，可以說明以液態餌劑與昆蟲生長調節劑型餌劑防有對控制黃狂蟻超級群落的成效。在取食工蟻密度調查也顯示，液態餌劑和生長調節劑可造成短期黃狂蟻數量降低的防治效果。
四、主要建議事項
1.未來仍需要以液態餌劑與昆蟲生長調節劑型餌劑防治作業搭配黃狂蟻誘引盒的防治模式，以餌劑控制黃狂蟻的工蟻數量，以誘引盒來移除黃狂蟻蟻后。
2.液態餌劑與昆蟲生長調節劑型餌劑防治面積由2公頃擴大至3公頃)與施藥量液態餌劑由15公升/公頃提高至20公升/公頃，固態餌劑由4公斤/公頃提高至6公斤/公頃，增加防治強度以控制防治地區的黃狂蟻族群。
3.持續每個月誘引盒與餌站監測點以監控黃狂蟻族群動態變化。
計畫類別：[動物生態]
英文摘要：1. Research background
Kenting National Park housing an extremely high abundance of land crabs. However, in recent years, it has been reported that the yellow crazy ant (Anoplolepis gracilipes) has invaded land crab habitat and even formed a more threatening supercolonies which has caused a significant impacts on the land crab populations. Survey findings of “2017 Investigation of invasion status and devise of management strategies of Anoplolepis gracilipes (yellow crazy ant) in Kenting National Park”, “2017 Survey of Anoplolepis gracilipes in Gangkou areas”, and “2018 Monitoring and control of Anoplolepis gracilipes in Kenting National Park” all have indicated that there were high density of A. gracilipes populations at land crab hotspots in Kenting National Park (Hsiangchiaowan, Shadao and Gangkou), and showing signs of supercolonies formation. “2020 Control plan of yellow crazy ant in Kenting National Park by the use of artificial ant nest” has successfully trapped and removed approximately 500 ant queens and 460, 000 ant workers from Hsiangchiaowan, Shadao and Gangkou areas. “2021 Control plan of yellow crazy ant in Kenting National Park” targeted, and broadcasted ant bait around coastal forest of Hsiangchiaowan and Gangkou area, in which both liquid bait stations and artificial ant nests were applied to monitor the population dynamics of yellow crazy ant in control areas. A total of approximately 1,150 ant queens and 250,000 ant workers were successfully trapped and removed.
2. Research methods
This year, total coverage area for chemical treatment was increased by 2 hectares for Hsiangchiaowan and Gangkou area, respectively. During 2021, a total of 6 times of baiting operations (i.e., liquid and solid baits) were implemented at Hsiangchiaowan and Gangkou areas where yellow crazy ant workers were found in large numbers. As a follow-up to last year control program, a total of 70 artificial ant nests were deployed to monitor the density of yellow crazy ant populations (i.e., Hsiangchiaowan: 40 artificial nests; Gangkou: 20 artificial nests; Shadao: 10 artificial nests as non-treatment plot). The locations of those artificial ant nests were based on the designed sampling points of “The 2021 project on the management and monitoring of yellow crazy ant in Kenting National Park”. In addition, a total of 20, 10, and 10 liquid bait stations were set up at Hsiangchiaowan, Gangkou, and Shadao, respectively, as monitoring points. Those artificial ant nests were replaced with new ones per month to monitor the changes of population dynamics of yellow crazy ant, and evaluate the long term control strategies and recommendations for yellow crazy ant populations in Kenting National Park.
3. Important findings
A total of 217 artificial ant nests, 1962 ant queens and 350,000 ant workers were collected during January to December this year, where highest number of ant colonies and worker numbers were recorded at Gangkou, and highest number of queen numbers were recorded at Hsiangchiaowan. Overall, the total number of ant individuals trapped in 2022 was higher than that trapped in 2020 and 2021, respectively. After treated with liquid bait and insect growth regulator, Hsiangchiaowan area showing significant downward trend in both number of ant workers and ant queens. By contrast, Gangkou area only showed downward trend in number of ant workers, while it appears there were no much influence on the queen number and number of ant colonies. In respect of months (March to August 2021–2022) when liquid bait and insect growth regulator were applied, it can be clearly seen that both the overall number of ant workers and nest proportion showed a gradual downward trend when compared to data from 2020. Coupled with the phenomenon of gradual aggregation of ant queens, it indicated that liquid bait and insect growth regulator are effective in suppressing the supercolonies of yellow crazy ant. Survey on the density of foraging ants also showed liquid bait and insect growth regulator are able to temporarily reduce the number of yellow crazy ant workers.
4. Main suggestion
1.In future, it will still be necessary to complement bait treatment (i.e., liquid borax bait and insect growth regulator bait) with deployment of artificial ant nests as management strategies of yellow crazy ant. Baiting is used for controlling the numbers of ant workers, while artificial ant nest is used for removing the ant queens.
2.The treatment area of liquid borax bait and insect growth regulator bait is increased from 2 hectares to 3 hectares, the application rate of liquid bait is increased from 15 liters/hectares to 20 liters/hectares, and the application rate of solid bait is increased from 4 kg/hectares to 6kg/hectares; increasing the intensity of control methods to control yellow crazy ant populations in treatment areas.
3.Continuously deploying the artificial ant nests and liquid bait stations (i.e., as monitoring points) monthly to monitor the population dynamics of yellow crazy ant.
辦理單位：國立彰化師範大學
計畫屬性：本處委託辦理
執行年度：111
計畫主持人：林宗岐
中文關鍵字：黃狂蟻、陸蟹、外來種、超級群落、餌劑防治
英文關鍵字：yellow crazy ant, land crab, exotic species, supercolonies, bait control