March and April are the months when the predominant flowers are white and yellow. However, it is the latter that attracts insects very strongly. The pigments in the plant cell sap are responsible for this color. The more xanthophyll there is, the stronger the yellow shade. On the other hand, carotenoids and carotenes cause the color to turn orange. In the case of white, it is the result of the accumulation of air in plant tissues.
Evolutionary plants have adapted their flowering times to pollinate them from the beginning of spring. Therefore, the first flowers that appear after winter are white and yellow. Insects will look for such petals to eat nectar and collect pollen. Bumblebees, bees and butterflies all have three visual pigments and can see ultraviolet light. In combination with yellow, a separate color is created, called "bee red".
We noticed increased activity of insects within the following plants:
- marsh marigold (Caltha palustris),
- ficaria verna (Ranunculus ficaria),
- yellow star-of-Bethlehem (Gagea pratensis),
- dandelion/common dandelion (Taraxacum officinale),
- common coltsfoot (Tussilago farfara),
- goat willow/great sallow (Salix caprea).
This confirms that the yellow color of early spring flowers is a rescue for insects on cold days.