Dermestes undulatus Brahm, 1790


Synonym(s) : 

  • Dermestes murinus Olivier, 1790
  • Dermestes vulpecula Herbst, 1792
  • Dermestes tessellatus Illiger, 1801
  • Dermestes carinus Gravenhorst, 1807 
  • Dermestes variegatus Brullé, 1832
  • Dermestes dissector Kirby, 1837
  • Dermestes cylindricus Casey, 1916

Common names

  • Dermeste bigarré


  • Order:  Coleoptera
  • Family:  Dermestidae
  • Genus:  Dermestes
  • Species:  undulatus

Frequency index:

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About 30 Dermestidae species (84 are recorded in France) are likely to infest our museums, heritage premises, warehouses, houses,… provided that they can find the right food in them.

The Dermestes genus alone comprises more than a quarter of the species of the Dermestidae family in France, and though common in natural environments, it has the highest number of commensal species within the family.

Dermestes (literally “skin-eaters”) are mostly carnivorous and necrophagous, and their voracious, often cannibal larvae feed on bodies and remains of animals (bones, feathers, hairs, skin, flesh,…), on dessicated insects, on pupae or nymphs(see “Infested Materials” chapter).

Though brisk and quick walkers, these insects are poor fliers, but they can spot food from very long distances (several hundred meters).
The Dermestes genus is easily recognizable thanks to its sturdy, elongate oval aspect and to the absence of a median ocellus on its forehead. Six more Dermestes species are described in fact-sheets in this website: D. olivieri (= D. ater), D. carnivorus, D. frischi, D. lardarius, D. maculatus and D. peruvianus. Readers can refer to them for more information about those pests.

Dermestes undulatus is common in the South of France. It preferentially seeks skins, furs and leathers (book-bindings,…), but can also be particularly harmful to animal collections (insects, stuffed animals).

Like most other species of the genus, it is particularly attracted by dried fish. This insect is very active during the summer-time ; in the South of France, it can be observed in natural environments till the end of October, infesting remains of dead animals, bee-hives, and bird's, processionary caterpillar's or wasp's nests.

Like most other Dermestidae, it is also a very useful forensic entomology indicator for the scientific police, for its presence on a body can provide valuable chronological information for determining when death occurred.

Together with D. carnivorus, D. frischi and D. maculatus , Dermestes undulatus belongs to the sub-genus Dermestinus, whose species are characterised by a dense hairiness on the ventral face of their abdomen, which hides the cuticle from sight.

Recognition criteria



5,5 to 7,5 mm


Sturdy insect ; egg-like, elongate shape. The pronotum is massive and is 1/3 of the elytra in length.

Body about 2.5-fold more in length than in width and covered with flat bristles of various lengths and colours.
Short, brown antennae, 11 articles; the last 3 are wider and form a wide, compact club.


Black elytra, mottled with flat, fine, short bristles of a whitish to bluish-grey colour, laid in rough waves or zigzags.
Pronotum almost entirely covered with characteristic brown and red bristles of various lengths.
Ventral surface of the abdomen covered with a pubescence of white bristles. Two black spots on the sides of each sternite ; the last sternite is almost entirely black but there are 2 isolated white spots next to the front border of the segment. The colour of this species can vary.



They are 10 to 12 mm long when mature.


Elongate, narrow, evenly narrower from front end to rear end. Hard, tough cuticle. Body covered with many sticking-up red-brown to black hairs, giving it quite a shaggy look. Some hairs are short, others are long.

On the 9th abdominal segment (the last one), presence of 2 sharp spikes called urogomphs. Seen in profile, these sharp ends are slightly curved toward the front part.


The whole body is red brown. The thorax and the abdomen bear a lighter-coloured, reddish dorsal stripe.
Nota: The morphology or colour features mentioned here can only be used with old larvae, generally 9 mm long or more.

Development cycle

Adults overwinter. They can live several months (6/7) ; in natural environments in the South of France, they are active from April to October. Oddly enough, we have very few precise biological data about Dermestes undulatus ; its development cycle appears to be very close to that of Dermestes lardarius, which is given below as a reminder :

The complete cycle lasts 6 to 9 weeks in optimal conditions, between 22 and 27°C with 65% relative humidity.
Fecundity is impossible below 15°C and above 30°C, but it is optimal when the food substrate is rich in nutrients and water.
Egg-laying starts as soon as early spring; females can lay more than a hundred eggs within up to 6 months.

They lay them in small groups (2 to 8/10) in the cracks of the infested substrate and in larval galleries. New-born larvae hatch about one week after egg-laying.

Larvae (like adults) are very brisk, they shy away from light and they pretend to be dead by curling up in a ball and stopping any movement when they are disturbed.

The number of larval stages required for their development depends on ambient temperatures and on food : it is 6 at 20°C and 8 at 27°C.

Before reaching the last stage, larvae stop feeding, seek a shelter or a cavity inside the infested material which has often been altered by the numerous galleries bored through it ; they remain there, immobile, in the pre-nymphosis stage.
Actual nymphosis takes place about 10 to 12 days later and lasts about 10 days.

Imagoes stay a few days in their cell before leaving it and taking flight to the outside world.
There can be 2 generations per year.

Similarly to many commensal insects, the total length of Dermestes undulatus's development cycle seems to depend very much on ambient temperatures and on the nature of the larvae’s food substrate.

Infected materials

Dermestes undulatus exclusively feeds on materials or products of animal origin.

The species is carnivorous and necrophagous, and eats dessicated insects or fragments of dead animals (stuffed or not), horn, hairs, dried meat and fish, animal skins and their by-products (furs, book-bindings, parchments, leather).

Its larvae can also be found in animal foodstuff warehouses, where it can grow at the expense of hams, sausages, various charcuterie delicatessens...

A mere mouse or rat body can be the cause of a true infestation.
That is why it is necessary to keep all high-risk places clean.

In addition to the damage caused to the feeding stocks, various materials and substances cited above, let us mention that larvae can thread and bore galleries and tunnels through all kinds of materials (wood, cork, wood-panelling, plaster,…) while seeking for nymphosis sites.

Therefore they can indirectly cause serious damage to other products than food.

Geographical distribution

The species probably originated from Europe. It is commonly found in Western Europe and can be found as far as Siberia.

It tends to spread worldwide due to commercial trade and can also be found in Africa, North America and Asia.