Moisture in flowers attracts pollinators



Flowers have several advantages for attracting pollinating insects: smell, color, but also … humidity! Thus, bumblebees are able to detect what researchers call “floral moisture”, reveals a study published on June 23, 2021 Journal of Experimental Biology.

Ventilate the nest to regulate humidity

Flower moisture is a particularly humid area within spaces that are free in the flower structure. Present in many species, it was created thanks to a combination of nectar evaporation and plant transpiration. “But it is not clear whether such variations in flower moisture can be used as a food signal, and this has been shown in only one type of pollinator, Hyles lineata “, note the British authors of this new study. However, the sensitivity of insects to ambient humidity is already well known, which was a clue for the scientific community. For example, the European bee takes into account the humidity in its nest. structures.

Sensillae – these sensory organs present on the skin of insects – are distributed on the antennae of bumblebees; they could also allow them to be sensitive to moisture. Until you discover those flowers? Researchers have evaluated this ability in terrestrial bumblebees (Terrestrial bomb). To do this, they designed artificial flowers that produced a controlled level of humidity that was identical to that that real flowers could develop. They also measured how much this moisture can affect the behavior of these insects in the diet.

Floral moisture, honest signal

By experimentally changing the humidity level on artificial flowers in a biologically important range, we show here that bumblebees are able to detect and use differences in humidity in the context of flower research.Bumblebees naturally prefer flowers with high humidity, which is a tendency in other pollinating insects. Terrestrial bomb it is indeed able to associate floral moisture with the presence of nectar. This can allow him to carefully choose the area in which he can settle.

Because floral moisture is strongly associated with nectar evaporation, it is offered as a “sincere signal”“that is, able to effectively demonstrate the nutritional reward that a flower can bring. Thus, low humidity can signal”lack of a temporary reward for pollinators (e.g. after a recent visit by another pollinator), allowing insects to avoid unnecessary visits to non-rewarding flowers“.”Our results show that floral moisture can be a signal that can be used much more widely than previously thought.“, biologists continue.”If moisture patterns are important for attracting pollinators, they are probably one of many different signals (like color, smell, and pattern) that a flower uses at the same time.“, note in Statement Dr. Sean Rands, co-author of this study. This signal could change climate change: it affects the humidity of the environment which in turn could affect the humidity of the flowers.



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