Asbolus verrucosus (Blue Death Feigning Beetles) BDFB Care Sheet

The blue death feigning beetle, also called the desert ironclad beetle, is a species of darkling beetle native to the Southwestern United States and parts of Mexico, found mainly in the Sonoran desert. The body of this beetle is black but covered in a waxy layer that provides protection from the sun and their distinct blue color.  When startled, they will lay motionless on their backs, feigning death, until the threat has passed. Like many insects, they undergo complete metamorphosis with egg, larva, pupa, and adult stages. All life stages of this beetle are harmless to humans, and their lifespan is thought to be about 8 or more years. As adults, their size ranges from about 0.5-1 inch (1.3-2.5 cm) in length.  With their active behavior, long lifespan, and easy care, blue death feigning beetles have become a popular pet insect.

Recommended day temperatures can range between 75-95° F (23.9-35°C) though this beetle species tends to be most active when kept between 80-85 (26.7-29.4°C).  Temperatures should drop at night to mimic natural conditions, but remain around 50-60°F (10-15.6°C). If temperatures drop below 50°F (10°C), a heat source would be beneficial at night. Blue death feigning beetles can be inactive if kept in cooler conditions for over a 24 hour cycle. This may be an indicator to raise the temperature. Having a probe thermometer set on the substrate, is an easy and inexpensive way to monitor enclosure conditions. Heat lamps come in a variety of sizes and are effective in providing stable warmth when on a thermostat. Any heat sources should be placed at one end of the enclosure to provide a warmer end and cooler end to choose from. At this time, it is thought UVB light is not necessary for this species.

Blue death feigning beetles are well adapted to their low humidity climate and obtain most hydration from their food.  Keeping a water dish with this species may be a hazard with their poor ability to swim, however ant water towers work well for a water source. Occasionally misting a small portion of their enclosure to provide additional water is recommended. Their enclosure should be kept dry with under about 20% relative humidity. An hygrometer, or humidity gauge, is an easy and inexpensive way to read the humidity. Improving the enclosure ventilation can help lower humidity if needed. Blue death feigning beetles that are wet or are kept in more humid conditions will be darker or black temporarily until conditions are drier.

These beetles are opportunistic and will feed on a wide variety of plant and animal matter in the wild. It is recommended to keep their diet lower in sugar and higher in protein. Rotate out food items several times per week to vary nutrition and provide a source of hydration. Suggested food options include but are not limited to:

● Seeds: Sunflower seeds and other unsalted, unroasted seeds.

● Produce, Roots, and Similar: Cactus, cactus fruit, lichens, mushrooms, lettuce roots, grass roots, and other plant roots washed well to avoid pesticides and fertilizers. While fruits and vegetables are readily accepted, it is best to limit high sugar fruits and root vegetables to occasional treats rather than staple food items.

● Protein: Bee pollen and fresh killed invertebrates such as crickets, superworms, mealworms, roaches, black soldier fly larva, and more.

● Other: Invertebrate gel mixes, low sugar agar based beetle jelly.

Blue death feigning beetles are active insects but cannot fly or climb smooth surfaces. Their enclosure should be a smooth glass or plastic container with good ventilation. When choosing an enclosure, horizontal space has more useable area than vertical space though they will climb any items placed in their enclosure. There should be enough space for all individuals to move freely with multiple hides to choose from. It is recommended each beetle have an area at least 5 times their body size. Larger is better as blue death feigning beetles tend to use all space provided. Clean aquarium decorations, wood, cork, rock, and dried leaves can all offer more climbing surface area, hides, and enrichment. Be sure there are no sharp edges or openings small enough to get stuck in. It is recommended to have a 2 layer substrate. The bottom 2 inch (5.1cm) layer should be a mixture of one part sand/clay (such as a reptile desert substrate) and 3 part decaying plant matter (such as millipede substrate). The top 1 inch (2.5cm) layer should be sand/clay (such as a reptile desert substrate).You can choose to change the substrate out a couple times a year to clean the tank.