Dermestes frischii
Adult females may lay 40 to over 400 eggs during a 2 month period. Eggs hatch in 5 to 9 days and the larva has 5 to 9 larval instars. The pupa stage lasts for approximately 10 days, after which adults emerge. The rate of development is mainly affected by temperature, developing faster and with fewer instars at 26 °C compared to 23 °C.
Dermestes frischii:
My longest thriving colony! They clean bones very quickly in warm conditions. This species is relatively tolerant of salt. They can survive a salt content of 25%, whereas the mortality of D. maculatus is 100% with a salt content of 9.2%.
Distribution: Nearly cosmopolitan.
Origin: Europe, Belgium. In my care since 2017.
Also a colony of the Western Sahara, Africa, since 2025.
Description: The adults are 6 to 10 mm long. The elytra are brownish to black and have, in contrary to Dermestes maculatus, rounded tips. The underside of the adult beetles are mainly white with a black spot on the last segment of the abdomen. The shape of this spot is an identification key for this species (see Figure 1). Full-grown larvae are 10 to 14 mm long. The larvae are dark-brown in colour and have a light-brown median stripe across their back.
Another identification key between this species and D. maculatus, is the pattern of the light-colored satae on either side of the thorax. In D. frischii, this pattern is fringed (see Figure 2), slightly comparible to the flames on a Hot Wheels car.
There is also a difference in the appearance of the larvae of the two species. In D. frischii, the dorsal stripe is interrupted on the prothorax - that's just behind the head (see Figure 3).
