Dermestes frischii
Biology: Neciobiont, with a preference for the carcasses of large animals. These beetles are relatively tolerant of salt and thus can be found on dead marine fish as well. They prefer a hot and dry summer and relatively humid winter. The optimum temperature is in the range of 30-35°C and the minimum is 20°C. The upper temperature limit is 40°C. They can develop in humidities of at least 30% RH and their optimum is about 75% RH.
Dermestes frischii:
This species is part of the maculatus species group together with Dermestes maculatus. D. frischii 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: Mixed continents. In my care since 2017.
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).
