I live in Africa (DR Congo). Here we have these insects that look like ants. They appear between May and June.

These insects give severe damage if crushed on the skin. They contain something like acid that burns the skin. I saw many people wounded by them.

So I would like to know what these insects are, and whether they can cause death if swallowed? Can someone point me to where I could learn more about them?

enter image description here

PS: There are no forests near where I live.


  • The insects appear at the end of the rain season (April, May) and right before the dry season (May, June).
  • Attracted by (neon) light. I think they fly only once then drop their wings (not really sure).
  • Can be found in homes (houses).
  • Can burn skin like acid.
  • It measures approximately 5 - 8 millimeters (not sure. can't find one right now).
  • Crawls fast with its tail upwards (don't know how to describe else, see image).
  • Solitary animal.

1 Answer 1


It is a Rove beetle of the Genus Paederus.

Why Paederus sp.?

  1. They are brightly colored rove beetles, Coleopterans with short elytra.
  2. Have metallic blue or green-coloured elytra.
  3. Have bright orange or red on the pronotum and basal segments of the abdomen.

There are widely spread on the planet and I found two species of Paederus sp. that are found in East of Africa, together they are called Nairobi flies.

enter image description here

The medical condition it causes is called Paederus dermatitis.

According to Medical and Veterinary Entomology (2009) "At least 20 of the more than 600 species of Paederus beetles have been associated with Paederus dermatitis", even though Paederus beetles do not bite or sting.

This skin irritation results from contact with pederin, a vesicant toxin in the hemolymph of many but not all females in the genus Paederus.

The toxin is manufactured, not by the beetles themselves, but by endosymbiont bacteria, probably some species of Pseudomonas.

Three different genera of rove beetles, all members of the same subtribe Paederina, can cause paederus dermatitis: Paederus, Paederidus, and Megalopaederus.


Pederin blocks mitosis at levels as low as 1 ng/ml, by inhibiting protein and DNA synthesis without affecting RNA synthesis, prevents cell division...

This makes it also a potent antitumour agent.

The manufacture of pederin is largely confined to adult female beetles—larvae and males only store pederin acquired maternally (i.e., through eggs) or by ingestion.

It is a contender of the title of most powerful animal toxin.

It is among the most potent animal products known, more so than Latrodectus venom, which is 15 times more potent than cobra venom.

Ingestion can cause severe internal damage and intravenous injection causes death ...

Further Reading:

1. Dermatitis Paederus: About 06 cases occurred in Bun ia, Democratic Republic of Congo



1. Paederus

2. Pederin

3. Paederus dermatitis

4. Encyclopedia of Entomology

5. The Role of Natural Products in Drug Discovery

6. ChEBI

Note: I found the picture in your question is the same as that of Wikipedia's picture of Paederus.

  • $\begingroup$ Oh thank you. It think this answers my question. The image was posted by a friend on Facebook so I thought would be better to ask here. $\endgroup$
    – esQmo_
    Commented Jun 13, 2017 at 20:14
  • 1
    $\begingroup$ Very nice answer, Tyto alba $\endgroup$ Commented Jun 20, 2017 at 17:15

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