黑棘蟻與入侵紅火蟻之種間競爭：評估具生物抗性之潛力物種

Interspecific Competition between Gray Black Spiny Ant (Polyrhachis dives) and Red Imported Fire Ant (Solenopsis invicta): Evaluation of Ant Species with Biotic Resistance Potential

吳岳樺(Yueh-Hua Wu) ； 許弘瑋(Hung-Way Hsu) ； 石正人(Cheng-Jen Shih) ； 楊景程(Chin-Cheng Yang)

《台灣昆蟲》 33卷2期 (2013/06) Pp. 107-120

https://doi.org/10.6661/TESFE.2013008

摘要

台灣於2003年首次發現入侵紅火蟻（Solenopsis invicta, red imported fire ant）蹤跡，主要分布於桃園、台北與嘉義兩地區。以當前火蟻防治策略而言，大量且密集撒佈餌劑輔以獨立蟻丘灌注仍為目前慣行模式，雖具控制火蟻蔓延之效，但藥劑昂貴且防治成效受天候因素影響甚鉅，如何能降低火蟻防治成本，同時保持良好防治效率，成為目前發展火蟻蟲害管理框架之主要趨勢。其中，找尋並扶植本土生物天敵物種是其中一個值得考慮之方式，此法不但提升環境抵抗外來物種入侵之能力外，也能降低入侵物種定殖成功機率，此概念即稱為生物抗性（biotic resistance）。因此，以台灣火蟻為例，強勢本土螞蟻為可能選項之一。田間觀察發現，強烈領域性之黑棘蟻 （Polyrhachis dives, gray black spiny ant）具主動攻擊火蟻個體之趨勢，因此可視為生物抗性之潛力物種，但相關行為資料卻仍缺少。本研究因此進一步評估黑棘蟻於個體或群體模式下是否具備與火蟻競爭優勢，並透過觀察兩蟻種間競爭行為探究黑棘蟻之攻擊模式。試驗結果指出，於實驗室條件下，黑棘蟻遭遇火蟻之行為傾向為主動競爭／攻擊型，群體試驗則觀察到黑棘蟻強烈之領域性及主動巡邏並攻擊火蟻蟻巢，造成 50～70％之火蟻死亡率。若以生物抗性角度而言，黑棘蟻似乎能於火蟻定殖初期，透過競爭／攻擊之方式降低火蟻建立族群之成功率。未來研究若著重於發現其他本土螞蟻物種，對於增加環境對於火蟻入侵時的生物抗性似乎有正面之幫助。

關鍵字

黑棘蟻 ； 入侵紅火蟻 ； 入侵種 ； 種間競爭 ； 生物抗性

並列摘要

Invasion of red imported fire ants (Solenopsis invicta) was first reported in Taiwan in 2003 with infestation mainly located in Taoyuan, Taipei and Chiayi Counties. Current control strategies of fire ants in Taiwan involve intensive bait broadcast supplemented with single-mound injection, which is believed practical on lowering spread of fire ants but considerably expensive in term of bait purchase and highly vulnerable to weather conditions (e.g., wet seasons). Development of efficient and self-sustaining control methods therefore holds the key for successful long-term containment of fire ants in Taiwan. Seeking and reinforcing native species as natural enemies is one of many that not only satisfy such criteria but also potentially elevate the resistance level of target environment against species invasion, an ecological process termed as ”biotic resistance”. Preliminary field observation indicates that highly territorial gray black spiny ant (Polyrhachis dives) attacks fire ants in an active fashion when encountering, suggesting the potential of biotic resistance, and, however, the relevant information of this native ant remains poor. The present study reveals that P. dives are highly aggressive towards S. invicta at individual-level competition, and that, at group-level competition, P. dives possess extremely patrolling behaviors followed by mass attack against S. invicta once they locate the nests of S. invicta. Our data further indicate that mortalities of S. invicta nests can reach up to 70% due to interspecific competition even S. invicta have access to the food source before P. dives do. These findings, along with some additional behavioral observations, suggest that behaviors of such kind displayed by P. dives may play roles reducing the establishment success of S. invicta, thus ensuring the control efficiency by maintaining the level of biotic resistance of a given area.

並列關鍵字

biotic resistance ； gray black spiny ant ； interspecies competition ； invasive species ； red imported fire ant