The harlequin beetle (''Acrocinus longimanus'') is a tropical
longhorn beetle native from southern
Mexico to
Uruguay. The harlequin beetle feeds on sap and is given this name because of its elaborate pattern of black, red and greenish yellow markings on the
wing covers of both sexes.
The species name ''longimanus'' is a
Latin word that refers to the extremely long forelegs (''manus'') of the males, which are usually longer than the beetle’s entire body. As an adult, the species is very large, with a body that can measure nearly 76 mm (3 inches) in length.
[ ] It is also famous for carrying
pseudoscorpions as a form of
phoresy.
The harlequin beetle exhibits
sexually dimorphic traits. The foreleg length, measured as the combined length of the femur and tibia, exhibits a greater degree of
allometry with increasing
elytral length in males than in females.
Large males may also exhibit strong curvature in their foreleg
tibiae
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
, which is not seen in females.
These traits aid the males as they fight with each other over optimal egg deposition sites in preparation for mating.
Males engage each other with their forelimbs in an attempt to flip other males off of the dead or dying trees that will be chosen by females to provide food for developing larvae.
The harlequin beetle contains three homologous
peptides
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides.
A p ...
, Alo-1, Alo-2, and Alo-3. Alo-3 was the first known peptide from insects to exhibit the
knottin
An inhibitor cystine knot (aka ICK or Knottin) is a protein structural motif containing three disulfide bridges. Knottins are one of three folds in the cystine knot motif; the other closely related knots are the Growth Factor Cystine Knot (GFCK) ...
fold.
It has a higher level of activity against the fungal species ''
Candida glabrata
''Candida glabrata'' is a species of haploid yeast of the genus ''Candida'', previously known as ''Torulopsis glabrata''. Despite the fact that no sexual life cycle has been documented for this species, ''C. glabrata'' strains of both mating typ ...
'' than the Alo-1 and Alo-2 peptides do.
Currently, there is a lack of treatment for fatal hospital-acquired infections and other pathologies. The peptide Alo-3 found in Harlequin beetles could provide a treatment for these severe, life threatening infections.
References
Further reading
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External links
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{{Taxonbar, from=Q1418844
Beetles described in 1758
Beetles of South America
Lamiinae
Taxa named by Carl Linnaeus