Dynastes Hercules
The Hercules is the world's largest rhinoceros beetle. They can be found in Central America and South America. For example, Mexico, Guatemala and Brazil. The male can reach up to 178 mm long. The females can reach up to 80 mm long. The males have yellowish elytra with black dots on them. Their magnificent horn can make up over half their total length. On the bottom of its top horn, there are lots of little orange hairs. Since this beetle is so huge, it was named after Hercules from Greek mythology. The females are brownish in color, with the edges near the back having a yellowish tinge to them. These beetles spend one to two years as a larva and about 6 months as an adult. However, if you care for them nicely, they can live up to 1 year old.
The male and female pictured above were a present from my brother-in-law. He bought them as larvae and spent two years looking after them before they became the adults you see above. The male is 152 mm long and the female is 70 mm. As a pair, this large size can be sold for up to 50,000 yen in some shops, so he did an amazing job raising them.
The male and female pictured above were a present from my brother-in-law. He bought them as larvae and spent two years looking after them before they became the adults you see above. The male is 152 mm long and the female is 70 mm. As a pair, this large size can be sold for up to 50,000 yen in some shops, so he did an amazing job raising them.
Not only is Hercules a huge beetle, but it also has a very interesting mechanism. Its elytra are able to change color from its yellowish color to black.
The Hercules to the right is the same one as pictured above, but the color difference is noticeable. So why does this happen? When the humidity is high, like it is in Japan's summer and in the beetle's container, the elytra appear black. When the conditions are dry, the elytra are a yellowish color. This happens since the elytra are porous, which means there are very small holes in it. In dry conditions, these holes are filled with air and allows the yellowish color. When the holes are filled with water, it allows the black color to be seen. The elytra can change from yellow to black and black to yellow over a few minutes if the humidity conditions change. In the photo to the right, the piece of wood he is standing on is the same piece he was standing on in the top pictures. He stripped off all the bark over the course of a month. |
Caring for Hercules Beetles
Hercules beetles are very easy to look after. You should use a matting that is a coniferous blend, as this minimizes the problems you may have with mites during the summer months. This matting should be kept moist and deep enough for the beetles to hide in. The female will often dig into the matting, but you will probably find that the male will spend most of his time on top. Place one or two large pieces of wood on top of the matting for the beetles to grip on to. Put in a shallow ceramic dish and squeeze the beetle jelly into it so that the male can easily access the jelly even with his long horn. It is best to use beetle jelly that is high in protein, as this will lengthen the life of the beetle. Hercules beetles should be able to live for one year. I have noticed that the male tends to stay in his ceramic dish on very hot days, perhaps as a way of staying cool. The optimum temperature for Hercules beetles is between 22 and 25 degrees Celsius.
Since they are such large beetles, you need to make sure that you have some large containers to put them in. Keep the humidity in the containers up by putting in some water on a regular basis. It is also best to keep the male and female separate until you are ready to breed them. |
There are a couple of things to be aware of with your container set up. Firstly, don't put in wood pieces that have gaps smaller than the beetle on them. The beetle will still try to go through the gaps and will get stuck. It took me an hour to carefully saw out the female to the right.
Sources also say that large beetles can become stressed in small spaces, so it is advisable to let them fly or roam around your house sometimes. My male Hercules took it upon himself to knock his lid off and found shelter in our toilet slipper. |
Breeding Hercules Beetles
After changing from a pupa to an adult beetle, it takes a bit of time for the Hercules beetle to start eating. You should wait at least a month after Hercules beetles have started eating jelly before pairing them to breed. The temperature should also be between 22 and 25 degrees Celsius.
If the above conditions are met, you can put the male and female together for about one week. During this time, they will hopefully mate. The males and females generally get along fine, but it is best to separate them as soon as possible after mating. It can sometimes be a bit of a challenge for the male to mount the female, as she will quickly try to avoid his grip. It might help to wait until the female is eating the beetle jelly before introducing the male in close proximity to make it a little bit easier. Also make sure there are big pieces of wood for them to stand on, which also makes it easier for them to balance and hold. |
While you are waiting for the beetles to mate, start to prepare another large container with humus for the female to lay her eggs in. In Japan, you can buy humus especially designed for Hercules beetles. The humus I used is simply called Hercules Matting. You should compact this humus with your fist to a depth of 10 cm.
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Add more of the humus on top of the compacted humus so that the container is about 80% full. The humus you put on top doesn't need to be compacted. You will find that the female will lay most of her eggs in the area just above the compacted part. Make sure that the humus is kept moist.
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Put in some beetle jelly. You can also add some wood pieces if you want to. Remove the female from its mating container and place her on top of the humus. You need to be careful as to how long you leave her in here. The longer you leave her, the more eggs she will probably lay. Females can lay up to 100 eggs if the space allows for it.
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The female may take up to 1 month before it starts laying its eggs. You need to be careful with your timing. If it becomes too cold, the eggs will not hatch. You need to keep the temperatures above 22 degrees Celsius.
The photos to the right show a female and one of its eggs on the surface of the humus. |
Caring for the Larvae
After you are happy with the length of time you have left your female in the egg laying container, you can return her to her original container. It is best just to leave the eggs in the humus. If you move them too quickly, it can be difficult for the eggs to hatch, It is best to wait 2 to 3 months until the larvae have become second instars. When this happens, you can move the larvae into large individual containers.
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The larvae will eat a lot of humus, so you will need to keep topping it up and removing the feces from the surface. If you want really big Hercules beetles, you should change the humus a few times a year and keep the temperature as close to 22 to 25 degrees Celsius as possible. This may require you to use an air conditioner in summer and a heating system in winter. I copied the heater system used by my brother-in-law to make the large hercules male you saw above. You need a panel heater and thermostat that are both commonly used for people who have reptiles as pets. A digital thermometer is also useful to monitor the temperature. Finally, you need a Styrofoam cooler box that has air holes or slit in it.
For Dynastes hercules, you can set the thermostat at 22 degrees Celsius. This is a good temperature for a range of beetle larvae. The cooler box above has three hercules larvae, two granti larvae and four rainbow stag beetle larvae.You can see the wires for the heater panel, thermostat and thermometer taped to the left-hand side of the cooler box. The heater panel is placed on the far side of the box. You can see that the outside temperature on this day was 15 degrees Celsius, but inside the cooler box it was 21.8 degrees Celsius. The orange light on the thermostat is on showing that it is letting the heater panel heat up a little more to get it to the set 22 degrees Celsius. This heater system is good to use during the winter months until it reaches spring..
The females will remain as larvae for about 1 year, but the males will stay as larvae for about 2 years. Large male larvae can weigh about 100 grams. The larvae will then start to make a horizontal pupa chamber. If the container is too small, the male will end up with a crooked horn.
Hercules beetles will remain as a pupa for about 2 months. Then they will spend another 1 to 2 months in dormancy before they start to become active. It is a lengthy and quite costly process, but it is really rewarding when you produce large Hercules beetles. |
Finally, two years after its egg was laid, this male Hercules was ready to be taken out of its pupa chamber.
Of the 3 Hercules larvae I had, two became males and one was a female. The female emerged much earlier than the males. Also, the smaller male emerged a couple of months before my largest one. |