Insect toxin

protein toxins produced by insect species

Many insects use poisons. They use them to protect themselves against parasites, and against predators. Some insects also use them for hunting and killing prey. These poisons are known as insect toxins. They are types of protein toxins. Sometimes the poisons arthropods use are called insect toxin as well; scorpions use them, for example.[1][2][3]

A blister beetle (hycleus lugens), with warning coloration.
A hornet.
An anthill.

There are different ways, in which these toxins can be applied:

  • Many insects use a stinger, which injects the toxin directly. Exaples of these are bees, and hornets
  • Some insects throw packets of poison, examples are beetles of the familiy Brachininae.
  • Some ants of the genus Formicinae, as well as caterpillars of the puss moth spray poison.
  • Ladybugs can secrete poison from their body. Other insects simply contain poison, to protect against predation.

Many poisonsous insects have a warning coloration.

Assassin bugs, sometimes known as kissing bugs, are one of the biggest and most diverse families of true bugs feeding on crickets, caterpillars and other insects. Some assassin bug species are bloodsucking parasites of mammals and even feed on humans. They are found around most of the world. Their size could be a few millimeters to as much as 3 or 4 centimeters.

The toxic saliva of assassin bugs is a mix of small and large peptides. It can stop moving by pre-digesting their prey. It is a defence against competitors and predators. Assassin bug toxins are homologous with the chemistry of marine cone snails.[4][5]

References

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  1. E. Zlotkin et al.: An excitatory and a depressant insect toxin from scorpion venom both affect sodium conductance and possess a common binding site. In: Archives of Biochemistry and Biophysics 240, Nr. 2, 1985, S. 877–887.
  2. M. E. De Lima et al.: Tityus serrulatus toxin VII bears pharmacological properties of both β-toxin and insect toxin from scorpion venoms. In: Biochemical and Biophysical Research Communications 139, Nr. 1, 1986, pp. 296–302.
  3. H. Darbon et al.: Covalent structure of the insect toxin of the North African scorpion Androctonus australis Hector. In: International Journal of Peptide and Protein Research 20, Nr. 4, 1982, pp. 320–330, doi:10.1111/j.1399-3011.1982.tb00897.x.
  4. Nakajima T, Corzo G, Nagao T, Kusui Y, Adachi-Akahane S (2001). "Novel peptides from assassin bugs (Hemiptera: Reduviidae): isolation, chemical and biological characterization". FEBS Lett. 499 (3): 256–261. doi:10.1016/S0014-5793(01)02558-3. PMID 11423127. S2CID 45675280.
  5. Darbon H, Mosbah A, Nakajima T, Bernard C, Corzo G (2001). "Solution structure of Ptu1, a toxin from the assassin bug Peirates turpis that blocks the voltage-sensitive calcium channel N-type". Biochemistry. 40 (43): 12795–12800. doi:10.1021/bi015537j. PMID 11669615.