The Aloeus Ox beetle (Stategus aloeus) is one of the larger species of beetles native to North America. It has a large habitat range which spans from the Southern United States to South America, but is most prevalent in Mexico and Central American regions. These black to reddish-brown beetles are distinguished by their three thoracic horns on males, two wider flattened horns on top, and a pointy horn right above their head, resembling the horns of a Triceratops. Females lack the large horns of males, only having a short pointy nub above their head, and instead sport a deep, ridged scoop on their pronotum to aid in digging.
While they are not a difficult species to keep and raise, they have a few peculiarities that would make them an intermediate species in terms of care. This is not meant to be an exhaustive guide on every possible way to care for these animals, but reflects our personal experience.
Basic care:
For adults:
Optimal temperatures: 70-85F/21-29C
Optimal humidity: 70-80%
Adult beetles can be kept in enclosed terrariums at least three times the length of the beetle in any given dimension, or larger. More space is better, but small terrariums are just fine. Males are best kept in separate enclosures, while females can be kept in small groups of two or three. They should be kept in a loose, soft substrate that is at least three or four inches deep – they are avid and adept diggers and like to hide when not exploring or feeding. Coco coir makes for a great substrate as it retains moisture well, will not scuff up and wear down exoskeleton as easily as soil, and resists mold. Sticks, leaves, and bark pieces should be placed on the surface of the substrate to give the beetles something to climb on and aid them in flipping over if they end up on their backs. A secure latching or sliding lid is highly recommended as they easily push open loose and pressure-fit lids. Metal mesh is fine, but not optimal, as it can wear down their claws faster than normal. The enclosure should be misted daily to maintain humidity, these beetles like to be kept in moist (but not soaking wet) conditions. Dry substrate or temperatures outside the optimal ranges can adversely affect adult lifespan.
Adults are sap and nectar feeders and will eat soft, sweet, ripe fruits in captivity. Banana, mango, and melon are commonly fed and readily accepted. Citrus fruits should be avoided. Beetle jelly is another alternative to fresh fruit, and can be purchased or easily made at home. Check our resource on making your own! Hungry beetles will dig into and destroy bark pieces looking for sap, so don’t put anything in the enclosure you don’t want torn apart.
Adult beetles, after eclosing and hardening, will remain buried and in a low-energy dormant state for another 2-8 months before becoming active, exploring, and eating. Once active, the typical lifespan is around 12-18 months, but can be as long as two years.
For larvae:
Optimal temperatures: 68-75F/20-24C
Optimal humidity: 70-80%
After hatching, larvae develop and gain weight through three separate stages before finally pupating, known as instars; normally referred to as L1, L2, and L3. In optimal conditions, a larva will spend about 3-4 weeks each at L1 and L2, and 5-10 months at L3. Taking care of larvae is a labor of patience, as your goal is to provide them with enough substrate and moisture to grow while disturbing them as little as possible.
The larvae feed on decayed wood and leaves. The best way to keep larvae in captivity is in a substrate of flake soil, an artificially decayed substrate made from sawdust and wood flakes. This can be purchased online, or made at home in 2-4 months. Check our resource on making your own!
Prepared flake soil should hold its shape when compressed in your hand without dripping water.
A normal terrarium setup isn’t the best method for keeping larvae. Lidded deli/food containers are perfect. Some ventilation holes are needed, 12-24 pinholes in the lid will suffice. L1 and L2 grubs will do well in a 5oz deli cup filled with damp flake soil. Early L3 should be upgraded to a 16-24oz container, and after a few months (we do around when the larva reaches 20g in weight) should be upgraded again to a larger container – we use 64oz containers.
The idea is to keep them in a size of container that will hold enough for the larva to eat in a single month. From there, you can check in and refresh the flake soil each month to sift out frass and replace the portion that has been eaten. Ideally, some of the remaining soil should be retained and mixed in with the fresh flake as it contains beneficial bacteria and will reduce the potential for shock to the larva from any PH differences between the spent and fresh substrate. Occasionally spraying the surface of the can help keep the substrate moist if it dries out some between changes.
Around the 3rd-5th (or later) month at L3, the larva will be frequently visible at the surface of their container and pace around the perimeter. This is considered “wandering” behavior. It happens when a larva is looking for a more suitable location to live – either for more food, or because it is looking for a place to pupate. If they’re due for a substrate refresh when you first notice wandering behavior, try refreshing half of the flake soil first in case they are looking for food. If they continue to wander after a week in the refreshed flake soil, they are likely looking for a better place to form a pupal cell.
At this point you’ll want to prepare a specific container setup that is more suitable to their needs. They will be looking for deep, moist, sticky soil in which to burrow and form a secure, hollow, oblong chamber horizontally as a pupal cell. To accomplish this, switch to using a container that is taller than it is wide, like a tall 32oz deli container or mason jar. Next you’ll want to get clean organic, garden soil with no amendments or additives like sand, perlite, or fertilizers. Clay heavy soils will work well. Remove any large inclusions like mulch bits, sticks, or stones.
Wet the soil enough so that it becomes sticky and moldable in texture (again, similar to clay soils). Next, fill your container about 1/3 full and tightly compact it down to form a dense layer of an inch or two on the bottom. Really press down hard – this is intended to create a sense of depth for the larva and act as a bottom bound for where they’ll want to dig.
Next fill up the container halfway again with the soil and compact less than the bottom layer, this is ideally where the larva will find suitable to form its cell.
Finally, make about a 50/50 mix of the old flake soil and the garden soil, put the larva in the container, fill the rest of the way up, and lightly pack the surface down flat before putting the lid on.
Don’t forget to poke holes in the lid! This gradient of different compression gives the larva the ability to dig down and find what it considers the best place to form a cell.
After 1-3 weeks, if satisfied with the conditions, the larva will have stopped digging around and formed a hollow, hopefully up along the side wall where you’ll have a window to see them still. If not, and they are still wandering on the surface after a few weeks, you may need to empty the container, re-mix, re-wet, and re-pack to try again. Likely the moisture content is not optimal, but finding a good, sticky soil can sometimes be difficult depending on the time of year or where you’re located in the country; commercial garden soils are typically made from locally-sourced forest products.
This prepupal stage can take between 2-4 months with them just sitting and doing nothing. You no longer have to do substrate refreshes, but placing the container somewhere warmer, between 75-85F (24-29C) does seem to help speed the process up. The larva will lose weight and become wrinkly as it uses fluid stored in its hindgut to line and smooth the chamber.
For Pupae:
After constructing a cell, the larva will lose all mobility and pupate. This is when the beetle is the most vulnerable and fragile. Any damage, even a minor crack or dent, will be fatal. The best thing to do for your pupa is not need to touch it.
Since they do best with a specific pupation setup, and no further digging is needed, damage to the cell is not often an issue. If you are unlucky enough that a visible cell is not present and check to see if an adult has emerged too early, or otherwise if somehow the cell is destroyed without killing the pupa, you will need to prepare an artificial cell. One method often used in the hobby is to carve a hollow recess into a block of dampened floral foam, approximately the size of the original pupal cell. It should not be much wider than the pupa itself, as the adult will need to be able to reach the sides to flip itself over when it ecloses. Keep in mind that the cells for S. aloeus are smaller and tighter fitting than other common rhino beetle species.
An easier method of preparing an artificial cell that we have started using is dampened 2-inch peat plant pots cut to fit together end to end. After placing the pupa inside, the artificial pot cell can be half buried again to secure it in place. When moving a pupa for any reason, the best way is to gently tilt them to roll into the palm of your hand so you can avoid accidental damage by picking them up with your fingers.
After 6-8 weeks, the color of the pupa will darken and the head, horns, and ends of the legs will be dark brown, indicating the beetle will eclose soon. A fresh adult will expand its wings and elytra and be soft and white, flipping over multiple times during the process as they begin to harden. If they are unable to flip over due to using too large of an artificial cell, the elytra may be deformed, or they may not be able to fold their wings properly. Elytra deformities may adversely affect the adult’s health, but misfolded wings are not usually much of an issue.
After a day, the adult beetle will have darkened to a deep orange red, and in a couple days they will have completely hardened and become a dark red color. As noted above, the new adult will remain dormant for 2-8 months before becoming active. These beetles do not need a cold dormancy. Warmer temperatures will cause them to become active faster, but can subsequently shorten their lifespan.
Breeding:
Ox beetles are are relatively easy to breed and a single adult female beetle can typically lay anywhere between 15-30 eggs if a suitable location is provided for her to do so. Pairing them is difficult to confirm as they are shy together and will mate while burrowed underground. The easiest thing to do is place the beetles in the same living container together for a week ensuring they have lots of depth to dig. After a week the male should be separated out and returned to his own enclosure, while the female can be placed in a specially prepared laybox, given plenty of food, and left to dig and get to work.
Laybox Preparation:
Optimal temperatures: 68-75F/20-24C
Optimal humidity: 70-80%
Choose a large container with a secure lid – plastic totes or bins work well. A 19Qt/18L storage bin or larger is recommended. Add ventilation holes. For the egg laying medium, a substrate of either pure flake soil, or a 50/50 mix of flake soil and organic garden soil (no additives like fertilizer, perlite, or definitely pesticides!) will work. It should be hydrated enough to hold its shape when compressed without crumbling. If using garden soil, it helps to sift out any stones, or mulched wood pieces to create a more uniform soil mix.
First, fill your bin halfway with loose substrate.
Next, press this down with your hands firmly to create a well-compacted layer at least 3inches/8cm deep.
Fill the rest of the bin back up to at least 50% of the way with more loose substrate.
Finally, add bark, sticks, plenty of food, and of course the female beetle to the bin and secure the lid, leaving it in a place where it won’t be disturbed.
Egg Collection:
Once you have a laybox prepared, it’s up to you for how you want to handle any eggs potentially being laid. You can simply leave the bin alone for a few weeks, changing the food as needed, remove the female, and then wait a couple months to dig in and look for larvae. We prefer to collect eggs to catalog and document how many eggs are being laid, and monitor egg development. This is our schedule and method:
Two layboxes are prepared using the same substrate.
Week 1: Female is placed in Box A.
Week 2: Female removed from Box A and placed in Box B. Box A is left alone, giving any laid eggs a week to absorb water, firm up, and become less fragile.
Week 3: Collect eggs from Box A. Return substrate and re-prepare Box A. Female removed from Box B and placed in Box A. Box B is left alone.
Week 4: Collect eggs from Box B. Return substrate and re-prepare Box B. Female removed from Box A and placed in Box B. Box A is left alone.
This pattern of rotating the two layboxes repeats until we are only finding a few eggs each week, and the beetle is returned to her normal enclosure.
During egg collection, the loose top layer is dumped off and sifted through by hand to see if any eggs were deposited near the surface; normally there won’t be any. The compacted layer is where most or all of the eggs will be. The compacted layer serves two purposes. The first is to create a sense of depth for the beetle, as she will try to dig and lay eggs in deep soil where they’ll be more safe. The second is to pre-compress the soil which lowers the amount of work the beetle needs to do form an egg chamber to deposit in. The female will use her ovipositor to hollow out a small hole that won’t collapse on the egg, so the compacted soil ensures it is more stable and require less work to prepare.
Gently dig out a section of the compressed layer, starting from an edge to try and avoid damaging any eggs. It should be able to be removed in mostly solid chunks. Break these chunks apart by hand, they will often split naturally along egg chambers.
Once eggs are found, they can be gently moved with a spoon and placed in a deli cup. Moist flake soil should then be lightly added on top, and a lid (with a few ventilation holes poked in it) put on. Invert the cup so the lid is on the bottom, this creates a dome where humidity and condensation will form and help the egg to continue absorbing moisture and develop. Freshly laid eggs are very sticky and fragile, but leaving the bin alone for a week lets them begin to develop and are less likely to break or go bad after collection.
Eggs will develop over the course of 4-6 weeks, and the curled larvae inside will become visible. Dark spots for mandibles and spiracles are able to be seen within a day of hatching. Fresh L1 larvae will often eat their egg shell while their head capsule hardens to a brown color, and dig down into the flake soil after a day or two. From here, refer to the larval care section above! Congrats!