Blue Death Feigning Beetle Care
Jenifer L. Nix, BVSc, MFAS, CertAqV
Basic Information: The blue death feigning beetle (Asbolus verrucosus) is a small species of darkling beetle that is native to the southwestern United States. The beetle is so-named because of a waxy coating that it secretes over its body to protect it from the extreme conditions of the desert, which gives it a blue color (1). When frightened, the beetles may “play dead”. Blue death feigning beetles can be extremely long lived, reaching at least 8 years in captivity as adults (1). Breeding is difficult in captivity and is rarely successful. Nearly all beetles in the hobby are wild caught.
Housing: These beetles do best in at least a 10 gallon tank with a screen lid to allow for adequate ventilation. Enclosures smaller than this do not allow for creating a temperature gradient. A tank of this size could house several beetles. A small heat lamp with a 15-25W bulb should be placed on one end of the enclosure to help keep humidity low and temperatures up. Surface temperatures should be in the mid 80’s (degrees Fahrenheit) on the warm side and mid 70’s on the cooler side. For substrate, the author uses pre-made Asbolus substrate from US Invertebrates, LLC. The bottom layer should be an organic topsoil and should be 1-2 inches deep, with a layer of sand. Please note that using only play sand or calcium-based sand is not appropriate- this does not give the beetle appropriate substrate to dig and it can make it harder for them to move around, requiring them to use more energy. Hides should be provided to give beetles places to shelter themselves from the heat and also to hide from conspecifics if needed.
Jenifer L. Nix, BVSc, MFAS, CertAqV
Basic Information: The blue death feigning beetle (Asbolus verrucosus) is a small species of darkling beetle that is native to the southwestern United States. The beetle is so-named because of a waxy coating that it secretes over its body to protect it from the extreme conditions of the desert, which gives it a blue color (1). When frightened, the beetles may “play dead”. Blue death feigning beetles can be extremely long lived, reaching at least 8 years in captivity as adults (1). Breeding is difficult in captivity and is rarely successful. Nearly all beetles in the hobby are wild caught.
Housing: These beetles do best in at least a 10 gallon tank with a screen lid to allow for adequate ventilation. Enclosures smaller than this do not allow for creating a temperature gradient. A tank of this size could house several beetles. A small heat lamp with a 15-25W bulb should be placed on one end of the enclosure to help keep humidity low and temperatures up. Surface temperatures should be in the mid 80’s (degrees Fahrenheit) on the warm side and mid 70’s on the cooler side. For substrate, the author uses pre-made Asbolus substrate from US Invertebrates, LLC. The bottom layer should be an organic topsoil and should be 1-2 inches deep, with a layer of sand. Please note that using only play sand or calcium-based sand is not appropriate- this does not give the beetle appropriate substrate to dig and it can make it harder for them to move around, requiring them to use more energy. Hides should be provided to give beetles places to shelter themselves from the heat and also to hide from conspecifics if needed.
Blue death feigning beetle (Asbolus verrucosus). JL Nix, 2023.
Basic Information
The giant vinegaroon (Mastigoproctus giganteus) is a large, large arachnid that grows up to 3.5 inches in length, excluding their whip-like tail (1,2). There are three subspecies of M. giganteus that live in and around Florida, Texas, and Arizona (1,2). The Arizona subspecies comes from an arid climate but is most active during the time of the monsoon, and therefore requires moisture in its environment (2). Like other arachnids, the vinegaroon’s body is comprised of a cephalothorax and abdomen, with eight legs (1,2). The first pair of legs are modified into long, sensory structures that it uses to examine its environment, while the other three pairs are used as walking legs (2). One striking feature of the giant vinegaroon is the large pair of pedipalps, which are modified as pinchers (2). The animal will use these to grasp prey and dig in the substrate (2). The vinegaroon has eight eyes, but its eyesight is poor (1). Vinegaroons are so-named because they produce a very concentrated mixture of acetic acid (vinegar) and other acids, which they will spray from their tail region at anything which threatens them (2). The vinegar mixture is harmless but may sting if you have a cut or get it into your eyes.
The giant vinegaroon (Mastigoproctus giganteus) is a large, large arachnid that grows up to 3.5 inches in length, excluding their whip-like tail (1,2). There are three subspecies of M. giganteus that live in and around Florida, Texas, and Arizona (1,2). The Arizona subspecies comes from an arid climate but is most active during the time of the monsoon, and therefore requires moisture in its environment (2). Like other arachnids, the vinegaroon’s body is comprised of a cephalothorax and abdomen, with eight legs (1,2). The first pair of legs are modified into long, sensory structures that it uses to examine its environment, while the other three pairs are used as walking legs (2). One striking feature of the giant vinegaroon is the large pair of pedipalps, which are modified as pinchers (2). The animal will use these to grasp prey and dig in the substrate (2). The vinegaroon has eight eyes, but its eyesight is poor (1). Vinegaroons are so-named because they produce a very concentrated mixture of acetic acid (vinegar) and other acids, which they will spray from their tail region at anything which threatens them (2). The vinegar mixture is harmless but may sting if you have a cut or get it into your eyes.
Decorations can consist of plants (succulents or plastic plants are fine- other types of plants may not do well in the type of environment that the beetles require). Cholla wood is often used in blue death feigning beetle enclosures. However, it is possible for beetles to get stuck in the holes of the wood, so these should be avoided. These beetles do not need a lot of moisture. In fact, too much moisture can be harmful. However, a small, shallow water dish should be provided to give them the option of drinking. The author uses a plastic milk cap as a water dish.
Feeding: In the author’s experience, these beetles can be fussy eaters, although other keepers have reported less picky beetles. They take to higher protein foods much easier. Fish food
(flakes, pellets, dried krill, etc.), reptile pellets, dead insects, or even thawed frozen pinky mice can be offered as food sources. Beetles may eat vegetables. You can offer shredded greens, carrots, bits of cucumber, etc. in small amounts. Avoid fruits and processed foods (sugary cereals) as these have little nutritional value for the beetles. Food should be changed daily.
Handling: These beetles are amenable to handling and make great education animals for this reason. They are not particularly fast-moving and may even play dead in your hands! Always be gentle with holding beetles as they can become injured with rough handling. They should not be held by very young children for this reason.
References
Feeding: In the author’s experience, these beetles can be fussy eaters, although other keepers have reported less picky beetles. They take to higher protein foods much easier. Fish food
(flakes, pellets, dried krill, etc.), reptile pellets, dead insects, or even thawed frozen pinky mice can be offered as food sources. Beetles may eat vegetables. You can offer shredded greens, carrots, bits of cucumber, etc. in small amounts. Avoid fruits and processed foods (sugary cereals) as these have little nutritional value for the beetles. Food should be changed daily.
Handling: These beetles are amenable to handling and make great education animals for this reason. They are not particularly fast-moving and may even play dead in your hands! Always be gentle with holding beetles as they can become injured with rough handling. They should not be held by very young children for this reason.
References
- (1) Blue Death Feigning Beetle (Asbolus verrucosus) [n.d.]. Cincinnati Zoo. (webpage)
- Accessed 12 January, 2024. Available from: https://cincinnatizoo.org/animals-archive/blue-death-feigning-beetle/
