Sunday, 22 September 2013

Giant flower beetles mecynorrhina torquata immaculicollis/ugandensis care

General requirements

Temperature: 20-26C; 25C day and night is optimal
Humidity: high for both larvae and adult.  Less humid for pupae.
Light: 12-14 hour day light/daylight bulb for adults.


     Larvae of giant cetoniidae normally require for their development mulched well-decayed leaves (preferably oak) mixed  with some top soil and a little of mulched soft rotten wood  (optional).  No conifers can be used for it, as they are toxic for the larvae. Part of the substrate needs to be replaced regularly once the most leaves are consumed. Larvae can be kept together,  however some breeders recommend to keep them separately, as some say that that the cannibalism is possible in some large cetoniidae. However in my experience I have never observed any cannibalism in similar size mecynorrhina torquata immaculicollis/ugandensis larvae.   Larvae need to be kept in closed plastic container, such as RUB, with a 2-5 pencil-size holes in its top,  in order to provide an air access.  Normally at least 2 liters container is needed for 1 L3 giant flower beetle larva. Once a larva has molted into its last 3rd (L3) stage, some protein supplement is normally recommended in order to obtain bigger adults, also many beetle hobbyists using protein supplements starting from the L2 stage of larvae.  1 pellet of Bakers Meaty Meals (1 kg box from supermarket will last for generations of beetles) needs to be placed at the bottom of the container per larva per week.  If pellet is not consumed within one week, then the food supplementing can be skipped.  Larvae should normally reach at least 30-40 g in weight before they get into the pupation stage.  It is always useful to weigh larva every couple weeks to ensure that it’s putting on weight. Inexpensive jewelry watches, which can be bought for a fiver on ebay, are great for this purpose.  During pupa period (6-7 weeks) larvae should not be disturbed as pupa may die inside pupal chambers or it may lead to the deformed imagos which normally will die shortly afterwards. It takes several days for larvae to construct pupal chamber out of substrate. With some care pupal cell can be gently removed and transferred into another container.


After adults come out of the pupae they do not feed for a few days. After that they feed on any sweet ripe fruits.  Ripe banana is recommended, as it contains significant amount of proteins. Commercially available beetle jelly is considered as a very good food for these beetles due its high protein content and because of it’s long life and resistance to moulding. Breeding container normally is a plastic box (20-30l) with about 20-25 cm of top soil at the bottom mixed with about  5-10% of rotten leaves and mulched decayed wood. Healthy males are very active and normally will chase females even underground. Mated female will lay eggs into soil. After female died soil needs to be carefully inspected and all larvae and eggs transferred into the larvae rearing boxes. Food needs to be present in the container all the time as it normally results in more eggs laid by females of giant flower beetles.

Monitoring the development of a larva with a jewelry scales.   Mid L3 larva of mecynorrhina torquata ugandensis.

Pupal cell of mecynorrhina torquata ugandensis. One opened cell at the bottom shows imago beetle still in it.

To see more photos of beetles, please visit my flickr page at

You can also contact me via
regarding availability of these beetles for sale or exchange.


  1. Hello! Useful caresheet, thank you.
    How long do they stay in each larval stage? And as adults?

    1. The speed of the development depends on temperature and a quality of the substrate.
      My normally spend about 3-4 weeks as L1, then 6-8 weeks as L2 and then 4-5 months as L3. As adults they normally live 3-5 months.

  2. Hi! Very useful caresheet, thanks! I have questions about pupae. You wrote that pupal stage lasts 6-7 weeks. I have had one pupa for about two months now... Is this normal? Or is it dead? Should I check it somehow? How do I know if it's dead or alive?

  3. Hi, it is on average 6-7 weeks; it could be a bit more or less than that. When pupae turns into an adult beetle, it stay in the cell for another 3+ weeks, it may come out earlier if it does not have enough stored energy/fat. The best way to check is to make a small hole in the cell and see; sometimes shedded skin can cover part of the cell, you can simply pull it out with small tweezers. By this time (2 months)it should turn into an adult beetle. if pupa still yellowish, it is alive, if it is very dark and smelly then it is dead. Hope this helps!

    1. Thank you very much! This was very helpful. I will check the pupa, and hope for the best... I also have one 3-week pupa and an L3 larva that should pupate very soon, so even if this first one were dead I hope I'll have more luck with the other ones. :)

    2. Checked it, it's definitely yellow. Maybe it will turn out okay after all... :)