蜜蜂会采丝瓜花, 估计蜜和粉都有。 紫外和蜜蜂视觉下, 雄雌两种花都会有很强的“蜜源引导” (简称蜜导 )。 I have previously seen many bees visiting this flower, perhaps for both nectar and pollen. The nectar guides are basically not there when seeing under natural light (what we see), but if you pay close attention, you see the inner circle is actually slightly brighter and smoother, the areas that are darker under ultraviolet light (UV). Under UV, the nectar guide is highly prominent, almost black due to the fact that most of the UV are absorbed and not reflected back. When I shot it using a different set of filters, with S8612 to block infrared (IR), and then UG5, which lets in some visible light AND UV, it has a nice green center. This is perhaps what insects, including honey bees are seeing. Beijing, China Sept 22, 2014 Cultivar in vegetable garden Synonyms: Cucurbita luffa hort. Luffa cylindrica M.Roem. Luffa aegyptica ( lapsus ) Luffa pentandra Roxb. Momordica cylindrica L. Momordica luffa L. Common Names: Luffa, loofah, 丝瓜 sigua (Chinese) Comment : Photographs taken with both female and male flowers, in the order of visible light, ultraviolet, and simulated insect vision. Reference : 1. Wikipedia (11 June 2015) Luffa aegyptiaca . Wikimedia Foundation, San Francisco, CA. Equipment Set A, a male flower. 1. Visible Light 可见光 2. Ultraviolet Light 紫外 2b. 100% crop of the flower showing trichomes (hairs) that absorb UV and shown as dark. 紫外局部 3. Simulated Insect Vision 昆虫视觉 Set B, a female flower. UV signatures are very similar. 4. Visible Light 可见光 5. 2. Ultraviolet Light 紫外 6. Simulated Insect Vision 昆虫视觉 Source: Huang, Z.Y. (2015) Luffa aegyptiaca Mill. (Cucurbitaceae) Luffa . Flowers ultraviolet and visible light. http://www.ultraviol...-...