Yano Shuichi, Shirotsuka Kanako
Laboratory of Ecological Information, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502 Japan.
Springerplus. 2013 Nov 27;2:637. doi: 10.1186/2193-1801-2-637. eCollection 2013.
An antipredator defence in the citrus red mite Panonychus citri, which does not produce protective webs, was examined experimentally. P. citri adult females lie down on citrus leaf surfaces with their dorsal setae (hair) directed in all upper directions. They seldom move in response to physical stimuli. Compared to normal lying females, both manipulated non-lying females and hair-removed females suffered higher predation by predatory mites. A predator approaching the body surface of a lying female inevitably created elasticity with a confronting seta, which eventually repelled the predator away from the female. These observations indicated that lying down with protective setae functions as an antipredator defence in P. citri females. This inflexible defence could also explain why the mite rarely runs away, even when it is consumed together with host plant leaves (via coincidental intraguild predation) by gigantic swallowtail caterpillars, against which protective setae are totally ineffective.
对不结保护网的柑橘全爪螨的一种反捕食防御机制进行了实验研究。柑橘全爪螨成年雌螨趴在柑橘叶表面,其背毛向各个上方伸展。它们很少因物理刺激而移动。与正常趴着的雌螨相比,经人工处理使其不趴着的雌螨和去除背毛的雌螨遭受捕食螨捕食的几率更高。捕食者接近趴着的雌螨体表时,必然会与相对的刚毛产生弹性作用,最终将捕食者从雌螨身边驱离。这些观察结果表明,带着保护性刚毛趴着是柑橘全爪螨雌螨的一种反捕食防御机制。这种不灵活的防御机制也可以解释为什么这种螨即使在与寄主植物叶片一起(通过种内巧合捕食)被巨大的凤蝶幼虫吃掉时也很少逃跑,因为保护性刚毛对凤蝶幼虫完全无效。