コーヒー害虫防除に役立つアリの新行動を発見（U-M Researcher Discovers New Ant Behavior That Could Help Protect Coffee From Pests）

2026-07-28 ミシガン大学

ミシガン大学の研究チームは、コーヒーの主要害虫であるコーヒーベリーボーラー（Coffee Berry Borer）に対するアリの新たな防除行動を発見した。従来は、大型のアリが害虫を捕食し、小型のアリがコーヒー果実内の巣穴から害虫を追い出すことが知られていたが、本研究では、小型アリが害虫の残した巣穴を自らの幼虫の育成場所（育房）として利用することを初めて確認した。害虫が作った空間をアリが再利用することで、アリはコーヒー果実内で繁殖しやすくなり、その結果、害虫の再侵入を防ぎ、天敵としての防除効果を高める可能性が示された。この現象は、生物が環境を改変し、その変化が他の生物に影響を及ぼす「間接的ニッチ構築（indirect niche construction）」の新たな事例と考えられる。研究成果は、化学農薬への依存を減らし、アリが本来持つ生態系サービスを活用した持続可能なコーヒー栽培や総合的病害虫管理（IPM）の発展に貢献すると期待される。

Ants foster their brood in a coffee berry that was once home to a coffee pest. Image credit: Jonathan R. Morris

＜関連情報＞

間接的なニッチ構築：コーヒーの害虫は、自身の天敵であるアリの繁殖を促進する

Indirect niche construction: A coffee pest facilitates its own ant natural enemies

Jonathan R. Morris

Ecology Published: 24 July 2026

DOI:https://doi.org/10.1002/ecy.70463

The ubiquity of niche construction in shaping ecosystems and their interactions is increasingly recognized by ecologists (Laland et al., 2017; Matthews et al., 2014; Odling-Smee et al., 2013). We now understand that many organisms modify their environments in a manner that has adaptive implications for individuals and in turn, may impact the dynamics of those species’ populations, both on ecological and evolutionary time scales (Laland et al., 2016). What is less well understood is how niche construction by one species impacts the fitness and ecological dynamics of other species (Kylafis & Loreau, 2011; Vandermeer, 2008). In predator–prey and consumer–resource interactions, there are salient examples where predators or consumers modify their niche to enhance the capture or consumption of their resource (Laland et al., 2017; Matthews et al., 2014). As examples, spiders construct webs to catch prey and leaf cutter ants cultivate fungal symbionts in their nests that are consumed as food. Similar top-down, indirect effects mediated by niche construction are likely common in ecosystems. However, effects in the opposite direction, where a prey’s niche construction has a bottom-up positive impact on a predator should happen much less frequently, due to the obvious negative fitness consequences for the prey and the potentially destabilizing impacts on predator–prey dynamics. When predators are facilitated by a prey resource, overexploitation could result in unstable predator–prey cycles (Arditi & Berryman, 1991; Luck, 1990; Vuorinen et al., 2021). If predators are broad generalists, however, the positive indirect impacts of prey niche construction may be diffuse enough to allow these interactions to persist.