We studied phototaxis, the directional movement relative to light, in the bumble bee Bombus terrestris. We first developed and validated a MATLAB-based system enabling reliable high-resolution tracking of a bee and a measurement of her distance relative to a changing LED light source. Using this system, we found in all our experiments that workers show positive phototaxis. The strength of the phototactic response was influenced by body size but not age, and this effect was significant when the light source was weak. In a separate experiment, foragers showed stronger phototactic response compared with nurses only in one of two trials in which they were larger and tested with weak light intensity. The evidence that phototaxis is associated with size-based division of labor in the bumble bee and with age-related division of labor in the honey bee lends credence to response threshold models implicating the response to light in the organization of division of labor in cavity dwelling social insects.

中文翻译：

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体型而不是年龄影响熊蜂 (Bombus terrestris, L.) 工人的趋光性

我们研究了大黄蜂 Bombus terrestris 的趋光性，即相对于光的定向运动。我们首先开发并验证了一个基于 MATLAB 的系统，该系统能够对蜜蜂进行可靠的高分辨率跟踪，并测量其相对于不断变化的 LED 光源的距离。使用这个系统，我们在所有的实验中发现工人表现出积极的趋光性。趋光反应的强度受体型而非年龄的影响，当光源较弱时这种影响很显着。在另一项单独的实验中，觅食者仅在两项试验中的一项中表现出比护士更强的趋光反应，其中一项试验是他们更大，并在弱光强度下进行测试。