12月14日,,《公共科學圖書館—綜合》刊登的一項研究"Paralyzing Action from a Distance in an Arboreal African Ant Species"表明,,一只普通的非洲螞蟻會在遠距離噴射威力強大的毒液來殺死白蟻。
在位于喀麥隆的森林的邊緣,,研究人員看見一個多達15只的螞蟻“團伙”(舉腹蟻屬螞蟻)從它們的蜇針中噴出一種有毒的煙霧去攻擊一只白蟻,。之后,螞蟻們呆在一個安全的地方遠遠地觀看著,,直到比它們個頭大得多的獵物變得全身癱瘓并死掉,。隨后,它們把白蟻運回自己的巢穴(如圖所示),。
這種通過遠程操控的“下毒”方式使螞蟻們能夠殺死獵物但卻無須把自己暴露于受傷的境地中,。僅毒液的威脅似乎就足以嚇跑敵人,包括其他種類的螞蟻,,從而使它們在遭遇裝滿了毒液的舉腹蟻屬螞蟻的蜇針時,,會放棄得來的蜂蜜滴而逃走。
研究者希望,,一旦能確定使白蟻癱瘓的細胞分子,,他們的發(fā)現(xiàn)將有助于發(fā)明新的殺蟲劑,從而有效對付那些對此前的殺蟲劑產(chǎn)品不屑一顧的害蟲,。
舉腹蟻屬螞蟻體長在4毫米左右,。頭部有縱長細條紋,頭后面條紋發(fā)散,。有蜇針,,會攻擊入侵者。當受干擾時,,會舉起腹部高于頭地奔跑,,由此被稱為舉腹蟻。(生物谷bioon.com)
doi:10.1371/journal.pone.0028571
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Paralyzing Action from a Distance in an Arboreal African Ant Species
Aline Rifflet
Due to their prowess in interspecific competition and ability to catch a wide range of arthropod prey (mostly termites with which they are engaged in an evolutionary arms race), ants are recognized as a good model for studying the chemicals involved in defensive and predatory behaviors. Ants' wide diversity of nesting habits and relationships with plants and prey types implies that these chemicals are also very diverse. Using the African myrmicine ant Crematogaster striatula as our focal species, we adopted a three-pronged research approach. We studied the aggressive and predatory behaviors of the ant workers, conducted bioassays on the effect of their Dufour gland contents on termites, and analyzed these contents. (1) The workers defend themselves or eliminate termites by orienting their abdominal tip toward the opponent, stinger protruded. The chemicals emitted, apparently volatile, trigger the recruitment of nestmates situated in the vicinity and act without the stinger having to come into direct contact with the opponent. Whereas alien ants competing with C. striatula for sugary food sources are repelled by this behavior and retreat further and further away, termites defend their nest whatever the danger. They face down C. striatula workers and end up by rolling onto their backs, their legs batting the air. (2) The bioassays showed that the toxicity of the Dufour gland contents acts in a time-dependent manner, leading to the irreversible paralysis, and, ultimately, death of the termites. (3) Gas chromatography-mass spectrometry analyses showed that the Dufour gland contains a mixture of mono- or polyunsaturated long-chain derivatives, bearing functional groups like oxo-alcohols or oxo-acetates. Electrospray ionization-mass spectrometry showed the presence of a molecule of 1584 Da that might be a large, acetylated alkaloid capable of splitting into smaller molecules that could be responsible for the final degree of venom toxicity.