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''Diamphidia'' or Bushman arrow-poison beetle, is an African
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of
flea beetle
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Though mo ...
s, in the family
Chrysomelidae.
The
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
...
e and
pupa
A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...
e of ''Diamphidia'' produce a toxin used by
Bushmen as an
arrow poison
Arrow poisons are used to poison arrow heads or darts for the purposes of hunting and warfare. They have been used by indigenous peoples worldwide and are still in use in areas of South America, Africa and Asia. Notable examples are the poisons se ...
.
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...
in 1773–1779, described the larvae as "poisonous worms". Hans Schinz
Hans Schinz (6 December 1858 – 30 October 1941) was a Swiss explorer and botanist who was a native of Zürich.
In 1884 he participated in an exploratory expedition to German Southwest Africa that was organized by German merchant Adolf Lüde ...
was the first scientist to document the process by which the Bushmen extract and use the poison.
The adults and larvae of '' Diamphidia nigroornata'' feed on '' Commiphora angolensis'' ( Engler), whereas ''Diamphidia vittatipennis'' eat African myrrh.
Life cycle
Adult females of ''Diamphidia femoralis'' Gerstaecker and ''Diamphidia nigroornata'' ( Stål) lay their eggs on the stems of ''Commiphora
The genus of the myrrhs, ''Commiphora'', is the most species-rich genus of flowering plants in the frankincense and myrrh family, Burseraceae. The genus contains approximately 190 species of shrubs and trees, which are distributed throughout the ...
'' species and coat the eggs with their faeces which hardens into a protective covering. As the larval instars develop, the pellets of their own faeces remain attached to their backs and posteriors.[Chaboo CS, Grobbelaar E, Larsen A]
Fecal Ecology in Leaf Beetles: Novel Records in the African Arrow-Poison Beetles, ''Diamphidia'' Gerstaecker and ''Polyclada'' Chevrolat (Chrysomelidae: Galerucinae)
(2007) ''The Coleopterists Bulletin'': Vol. 61, No. 2 pp. 297–309 The final instar sheds this faecal coat when entering the soil to pupate. The same behaviour is found in ''Blepharida'', a Flea Beetle
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Though mo ...
and ''Polyclada'', the African Leaf Beetle.[ The ''Diamphidia'' larvae burrow down for a depth of up to 1 metre in the sand under the food plant, where they may lie dormant for several years before going through a very rapid pupal phase.
]
Toxin
Diamphotoxin, the toxic compound in ''Diamphidia'', is highly labile
Lability refers to something that is constantly undergoing change or is likely to undergo change.
Biochemistry
In reference to biochemistry, this is an important concept as far as kinetics is concerned in metalloproteins. This can allow for th ...
, and has a low molecular weight
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...
. It is bound to a protein that protects it from deactivation.neurotoxic
Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specificall ...
effect, it produces a lethal haemolytic
Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo o ...
effect, and may reduce haemoglobin levels by as much as 75%, leading to haemoglobinuria
Hemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is caused by excessive intravascular hemolysis, in which large numbers of red blood cells (RBCs) ...
.[CY Kao, MJ Salwen, SL Hu, HM Pitter, JM Woollard]
Diamphidia toxin, the bushmen's arrow poison: possible mechanism of prey-killing
''Toxicon'' (1989) 27: 1351–66; accessed on ionchannels.org website
Diamphotoxin is only toxic to mammals when injected into the bloodstream, not when ingested, making it unclear how it protects the larvae. It has been hypothesized that the toxin may be harmful on ingestion for non-mammal species.
Parasite host
''Diamphidia'' is parasitised by a carabid '' Lebistina'' beetle, the larva of which attaches itself to a mature ''Diamphidia'' larva, clinging to it until the ''Diamphidia'' has formed its cocoon, enclosing both host and parasite, and then feeding on its host's soft tissue. The ''Lebistina'' larvae are more toxic than their hosts and are preferred by San hunters for arrow poison.[How San hunters use beetles to poison their arrows]
, Biodiversity Explorer website
Gallery
Image:Diamphidia fg01.jpg, '' Diamphidia nigroornata'' larva
Image:Diamphidia fg02.jpg, '' Diamphidia nigroornata'' cocoon
References
External links
Harvard Entomology Database
African Ethnobotany
{{DEFAULTSORT:Diamphidia
Alticini
Chrysomelidae genera
Poisonous animals
Taxa named by Carl Eduard Adolph Gerstaecker