Pictured is a red-footed tunnel bee Halictus rubicundus cleaning the antennae with its forefoot, which places the tentacles between the turns, where there is a special structure - the "tentacle cleaner".
In order to ensure the sensitivity of the antennae to external sensations, it needs to clean the antennae with its forefoot from time to time. Bees' antennae can sense taste, smell, humidity, temperature, etc., as well as determine wind speed, sense air vibrations, communicate with each other and capture pheromones. Therefore, in order to ensure that it works normally and stably, it must be kept clean. In the words of biologist Robert Dunn: Dirty tentacles can darken the world.
The cleaner consists of a tibia segment of the forefoot and a basal appendage. The base is a semicircular notch covered with a row of bristles, as well as a movable bone spur - "growth of the tibia". When the foot is bent, the bone spurs cover the grooves, forming a closed ring, and the bone spurs and bristles remove pollen or dirt as the antennae pass through the rings.
Usually a bee doesn't clean two tentacles at the same time, even if both are dirty – it cleans one first and then the other (presumably needing one to work online). All bees have this function, but differ in morphological details depending on the population.
Rob Dunn has written about the tentacles of the blackwood worker ant Camponotus pennsylvanicus and the German cockroach Blattella germanica, and the clean antennae help them perceive the outside world even more. He did experiments in which cockroaches were not allowed to clean their antennae, allowing dust and dirt to accumulate on their antennae, as well as the stratum corneum. It was found that this reduced its sensitivity to pheromones and other odorous substances. Similar experiments have been conducted on flies and ants. Cleaning the antennae is necessary for most insects, which work the same way but come in different shapes. There are tentacle cleaners in bees and ants, but not all insects have this particular organ, and some insects clean their antennae with front legs without special structures or with their mouths.
Author: Yulia Mikhniević
Compiler: Kudulaiti Akbar