A halfway breeding report for Mesotopus tarandus

Mesotopus tarandus is a beautiful African species. There are two known species Mesotopus tarandus and Mesotopus regius. But it depends whom you are talking to, as some consider M. regius as a subspecies of M. tarandus with elongated mandibles. These are shiny black beetles that can vibrate (like a cell phone in silent mode) and I am yet to find another beetle with the ‘buzzing’ ability. It was supposed to be impossible to breed until a few years back, when hobbyists (in Japan?) found out that the larvae, unlike other Lucanidae need a specific kind of mushroom mycelia in the wood that they eat. Most Lucanidae are not too picky when it comes to mushroom species, as long as the wood is in the right degree of decay and hardness. To give an example, for a Dorcus curvidens it does not matter if the wood was decayed by Shiitake (Lentinula edodes) or the Lung Oyster (Pleurotus pulmonarius), or even Reishi (Ganoderma lucidum). I have tested the first two options and it worked, I cannot yet promise for Reishi, but heard it works as well (Thanks to C. MONSTERLET for this information)

Mesotopus, and the Asian Allotopus however, are much more picky: The females will only lay eggs into wood that is infested by the Turkey Tail Mushroom (Trametes versicolor). Otherwise, well (at least in my case) no eggs, no larva, no breeding success.

Last year July, my friend Petr MALEC gave me a small male of Mesotopus tarandus from a shipment from Cameroon and then I started looking around for a female. Luckily I had the opportunity to visit Japan, and managed to purchase a female there, as well as a so-called kinshi bottle with Trametes versicolor. I then put the two together, assured a mating and prepared a breeding box for the female.

With Mesotopus, this is rather easy: Take a small container, screw the kinshi bottle open, put a bit of substrate, so that the female does not need to walk on bare plastic and wait. In my case, well for a long time nothing happened. Only when it got colder (around 22 degree Celsius) the lady started to make a tunnel into the kinshi. I suspected her laying eggs, but did not verify in order not to disturb her. She then stayed in the glass for months. I recently shifted and remembered that breeding box again. When I checked the tunnel, the female was still inside. The big surprise was that there was also a L3 larvae in the kinshi. So, I took the female forcefully out and fed her with jelly. She seemed starved and ate an entire jelly within one night. I guess that the mushroom growth had locked her inside the tunnel. The larva continues to eat and grow in the glass, I will soon need to check if there are more larvae in the same bottle, which seems likely.

Mesotopus tarandus L3 larvae in Japanese Trametes Kinshi

I agree that with Japanese substrate, breeding Mesotopus is an easy thing to do. But they are nonetheless still very costly in Japan. Why exactly, I am not sure, but I guess that they are not very productive egg layers.

However, the good news is that I also received two home-made kinshi bottles from Christophe MONSTERLET (Thanks again for the fast help!), which the female uses now. She just started making her tunnel again. So, even with European beech wood, Trametes kinshi is interesting enough for the African Mesotopus tarandus females to lay eggs.

I would also like to thank Daniel AMBUEHL and Christophe MONSTERLET for sharing their knowledge on how to grow mushrooms and also how to prepare kinshi outside of Japan. Christophe is quite successfully breeding Allotopus on his home-made Trametes Kinshi. Now we can also add Mesotopus tarandus for the European kinshi producers. I do not yet have a better picture of the small Swiss Mesotopus larva J and do not want to disturb her. One last thing that I noticed with regards to Trametes kinshi: Compared to the Pleurotus pulmonarius kinshi it is really rubbery and difficult to crumble. I will keep you updated on the breeding and add more information, as I get it. I am yet to see the eggs of Mesotopus, which unlike all other known Lucanidae, are said to be green in color. Oh, and since Trametes versicolor is a very common mushroom in our forests, I would be surprised if wood pieces that have been infested with Trametes versicolor would not work as well. Thanks to Daniel AMBUEHL, I do have a rather fresh piece of wood with Trametes, but I guess it is still too hard and fresh to be attractive for the female Mesotopus. According to Daniel, other Trametes species could work as well. Let’s try and see 😉

Mesotopus tarandus wild caught male