Data from: Ants and ant scent reduce bumblebee pollination of artificial flowers

Ants on flowers can disrupt pollination by consuming rewards or harassing pollinators, but it is difficult to disentangle the effects of these exploitative and interference forms of competition on pollinator behavior. Using highly rewarding and quickly replenishing artificial flowers that simulate male or female function, we allowed bumblebees (Bombus impatiens) to forage (1) on flowers with or without ants (Myrmica rubra) and (2) on flowers with or without ant scent cues. Bumblebees transferred significantly more pollen analogue both to and from ant-free flowers, demonstrating that interference competition with ants is sufficient to modify pollinator foraging behavior. Bees also removed significantly less pollen analogue from ant-scented flowers than from controls, making this the first study to show that bees can use ant scent to avoid harassment at flowers. Ant effects on pollinator behavior, possibly in addition to their effects on pollen viability, may contribute to the evolution of floral traits minimizing ant visitation.

停栖于花朵上的蚂蚁可通过取食花蜜报酬或干扰传粉者，从而破坏传粉过程，但学界难以厘清这两种剥削性与干扰性竞争形式对传粉者行为的具体影响效应。本研究使用具有高报酬且可快速补充的人工花朵（模拟雌雄生殖功能），让北美熊蜂（Bombus impatiens）开展觅食实验，设置两组处理：(1) 存在或不存在红蚁（Myrmica rubra）的花朵环境；(2) 存在或不存在蚂蚁气味信号的花朵环境。实验结果显示，熊蜂在无蚂蚁的花朵间转运的花粉类似物量显著更高，这表明蚂蚁的干扰竞争足以改变传粉者的觅食行为。同时，熊蜂从带有蚂蚁气味的花朵中取走的花粉类似物量显著低于对照组，本研究也首次证实熊蜂可通过感知蚂蚁气味来规避花朵上的蚂蚁骚扰。蚂蚁对传粉者行为的影响（或还包括其对花粉活力的影响），可能推动了那些可减少蚂蚁访花的花部性状的演化。