Many insect species hear using tympanic organs, membranes roughly similar to our eardrums, but located on their feet. Grasshoppers, praying mantises and moths have them, and for decades we thought that female stink bugs Dinidorids The family also has them, although they are located somewhat unusually on the hind legs rather than the front legs.
Suspecting that they use the drum organs of their hind legs to listen to male mating songs, a team of Japanese researchers took a closer look at these organs. Megimenum gracilicornA Dinidorids A species of stink bug native to Japan. They discovered that these “drum organs” were not what they seemed. These are actually mobile fungal nurseries like we've never seen before.
Portable gardens
Dinidorids are a small family of stink bugs that live exclusively in Asia. The insect did receive some scientific attention, but not as much as its larger relatives. Pentatomids. Previous work on the characteristics of organs growing on the hind legs Dinidorids Thus, the number of women was somewhat limited. “Most studies have been based on taxonomic and morphological approaches. Some taxonomists have described that female stink bugs Dinidoridae have an enlarged part on their hind legs that looks like a tympanal organ, which can be found, for example, in crickets,” said Takema Fukatsu, an evolutionary biologist at the National Institute of Advanced Industrial Science and Technology in Tokyo.
Based on their appearance, these parts were classified as tympanic organs – the body was closed and remained closed until Fukatsu's team began to study them more closely. In most insects, the tympanic organs are located on the forelegs rather than on the hind legs or abdominal segments. The original goal of Fukatsu's research was to find out what effect this unusual position had on the ability of female dynadorids to hear sounds.
At the beginning of the study it turned out that regardless of Dinidorids females do not have drum organs on their hind legs. “We found no eardrum and no sensory neurons, so the enlarged parts of the hind legs had nothing to do with hearing,” Fukatsu explained. Instead, the organ contained thousands of small pores filled with benign filamentous fungi. The pores were connected to secretory cells that secreted substances that Fukatsu's team hypothesized were nutrients that allowed the fungi to grow.
