Wide-Horn Hissing Cockroaches - Gromphadorhina oblongonota

Disclaimer: I can only attest to how the species I keep respond under the conditions I keep them. Even the best care under a certain set of parameters may be met with failure under others.

For any questions or to mention anything I have wrong or have missed, email me at rockinroachesandmore@gmail.com!

Summary

The Wide-Horn hissers are tricky. I've had limited success with them, which I tentatively attest to their slow reproductive cycle (slower than all other species I've kept) and the specific conditions they need to breed successfully, which must be consistently met. I've seen an extremely successful colony under conditions very similar to the ones I keep them under, yet mine have only successfully reproduced once in two years. The ones I have are all adults, and very solid and active (the males hiss louder and far more often than any of my other hissing species during their territorial squabbles), yet still the problem of more roaches persists. Could it be too low a humidity? Too small a tank? Simply a problem of insufficient sticks for the males to lay claim to? At any rate, though their care is very similar to that of other hisser species, the Wide-Horn hisser is much pickier about how it is kept. Once a colony lands in that goldilocks zone, it flourishes, but if not, the species seems to stagnate. Though it is my favorite species of cockroach, I would not recommend it to many.

Feeding

The Wide-Horn hisser isn't picky, but it does seem to enjoy mixing it up every so often. Otherwise, their feeding is identical to other hissers. They prefer fruits over vegetables, but will readily accept both. Mine do very well on a steady diet of old oranges, apples forgotten at the back of the fridge, and cut-up whole carrots. I have also successfully fed them watermelon, squash, zucchini, and grapes. For some reason, strawberries are not such a bit hit, except the tops; they do like their strawberry leaves. In addition to a diet composed predominantly of fruits and vegetables, they require some form of protein, given based on the size of the colony and about twice a week. Mine are given cat food, but I imagine any sort of kibble would go over well, as well as fish food. I would not suggest any kind of raw or cooked meat, fish, or shellfish, though only because of the inevitable smell.

Environment

Wide-Horn hissers, require a warm environment, and will not do well otherwise. The room I keep mine in is 80°F (26.7°C), with an approx. humidity of 60%. The species prefers 75°-85°F, but can withstand short experiences above that (as evidenced by an accidental night at 90°F) and will survive at temperatures lower than this, though I'm not sure where the lower limit lies. Any temperature below optimal will cause a decline in growth rate and activity of the colony, and may result in an increase in mortality. It is very important that this species be kept warm. Some keepers opt to provide their hissers with secondary heat sources, preferably a weak heat mat stuck to the side of the enclosure, NOT a heat lamp (too much heat, and they dislike the light) or too strong a source.

This species enjoys water more than other hissers. While not necessary - they get all the water they need from their food - my colony always goes to drink from droplets on the sides of the tank when I mist them, and prefers to be watered in this way every day. A shallow water dish with small pebbles or marbles may be provided, but I find the risk of drowning new nymphs too high. Otherwise, ensuring the colony always has some food with a high water content (oranges, apples, watermelon, grapes, zucchini) will be sufficient. This species prefers to be kept slightly damper than most other hissers kept at the same temperature and humidity.

Light is a non-issue for this species. They don't require - or want - additional sources beyond a room light, though they don't seem to mind indirect sunlight from a window. Ensure the enclosure is never in direct sunlight!

Enclosure

This is a very large species, and a small starter colony of 6-12 roaches can be kept in a regular 10-gallon glass tank only up until there are ~20 adults and assorted nymphs, depending entirely on the surface area of the hides they are given. They may also be kept just as easily in a Rubbermaid bin, or any largeish plastic container of a similar size, though that's not as pretty. A lid is encouraged, but not completely necessary as long as other precautions are taken (a line of petroleum jelly at least an inch thick around the perimeter of the inside lip of the tank, removal of anything in the tank that may be used by the roaches to climb out). As substrate, the options are flexible. If cost is an issue, the roaches will do well on regular outdoors soil, though I strongly suggest laying it out in a 1in thick layer and baking it at around 400°F for 20 minutes, or until totally dry, first, to prevent taking home unwanted hitchhikers or disease. I also strongly suggest you take extreme care to select soil that has not had fertilizer, insecticide, or any strong chemical applied, as the roaches, often detrivores in the wild, will nibble on most anything you put in their tank, including the substrate. Otherwise, coconut coir or (if the only option, for it's unsustainably harvested) peat moss will hold moisture and work well. This is not a burrowing species, an inch or two will be just fine. Just dampen it first, to prevent particulate matter from covering everything (and making you sneeze!) when you put it in the tank

Once you have your substrate, it's on to the décor. Egg flats will work, but as these roaches are both very large and very territorial, the males prefer to be on top of whatever you've given them, instead of hiding. Each male will stake out a claim, and only allow females into his space. Because of this, they enjoy vertical space as much as or more so than horizontal, though they aren't exceptional climbers. I suggest large flat pieces of bark and sturdy twigs. It doesn't need to be cork bark, just something appropriately sized you find outside and either forget in the back of a closet for a few months to dry out, or send through the oven at the aforementioned 400°F for 20min or so. The more the better, and a 10-gallon tank can hold more than you think.

In addition to the purely utilitarian purpose of giving the roaches a hide, the contents of the tank can make it nice to look at, too. A well-set up roach tank full of handsome little guys is simply nice to look at. To this purpose, I often use plastic fake plants. I get them more than half-off at Michael's seasonally, and they really add something. Before putting them in the tank, always wash them thoroughly. I use Dawn dish soap and warm water, let them soak for a while, then give them a good scrub, let 'em dry, and throw them in the tank to arrange. Additionally, one may add leaflitter. I add some leaflitter (oak, maple, etc.) to all my roach tanks. Only a rare few species ever eat any of it, but it looks good and, most importantly, gives the nymphs somewhere to hide that retains more moisture than the rest of the tank. For this reason, I highly recommend tromping around outside and picking some up, if you can. The Wide-Horn hisser, in particular among the hissers, needs somewhere low to the ground and layered for the nymphs to hide and retain moisture.

Other Information

• Adult size is 3in for females, 3.15in for males
• Ovoviviparous
• Wingless
• Climb well when young, watch out!
• My largest male weighs in at 23g!

A male Wide-Horn hisser (note the impressive horns).

Back