Plaesiorhinella watkinsiana
These are very pretty beetles originating from Cameroon. They often readily available as wild caught adults, but breeding them in captivity has been met with mixed success and some scepticism from other breeders.
Our Story
We started with eight adult beetles, but limited knowledge on how to breed them in captivity. We placed all the beetles together in a tank 3/4 filled with oak leaf mulch, dried leaves, white wood and our own fully organic compost. We compressed the bottom layer of compost and then added some white rotten wood and very finely shredded oak leaf litter before filling the remainder of the tank with a mix of all the above components. Initially we kept these beetles inside at around 19-20 degrees with the natural benefit of a day/night cycle. After three weeks we moved them into a dark heated cabinet at 22 degrees. After one month in the warm cabinet I checked the substrate for eggs and found 28 L1 larvae in the bottom layer of compost. Seven of the adults were deceased but one female remained so she was returned to the cabinet for a further month incase she would lay more eggs.
To reduce the chances of cannibalism and disease in our larvae we tend to house all our larvae individually. Although this takes up a lot more space it certainly yields much greater results and a higher chance of them becoming healthy adults. I checked our larvae on February 12th 2025 and all 54 of them were alive and growing well so I sorted them into larger tubs for communal living.
For pupation we tried several different methods this year:
- A sandier substrate that might replicate their natural environment.
- A damp leaf mulch substrate
- A drier leaf mulch substrate
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By trialing three different pupation substrates we were able to draw the following conclusions:
-A sandy substrate meant the larvae produced fragile pupal cells which were broken easily by other larvae and our own searching of the substrate, many of these larvae did build new pupal cells but seemed to then lack the energy required to metamorphose into a pupa.
-A damp leaf substrate resulted in well formed pupal cells but resulted in high losses due to the excessive moisture.
-A drier leaf substrate proved to be best option for this species with almost all larvae successfully eclosing into fully formed adult beetles.
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We have sold the majority of our adults and larvae of this species now but may revisit them in the future.
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The single remaining female did indeed lay more eggs as another twenty-six L1 larvae were removed from the substrate just one month later. It is, of course, possible that some of these larvae may have hatched from eggs we missed the first time around, but regardless of which female laid them we now had a total of fifty-four larvae.