News

A new rhino-beetle species from Bolivia by R. Perger and P. Grossi

Oryctophileurus guerrai
Oryctophileurus guerrai

By A. Santos-Silva, Z. Komiya and E. Nearns

New genera and species of Neotropical Rhinotragini by Larry G. Bezark, Ubirajara R. Martins, Antonio Santos-Silva & Amy Berkov

 

Hexamitodera (Sulcognatha) blairi
Hexamitodera (Sulcognatha) blairi
Calocosmus magnificus
Calocosmus magnificus

Morphological analysis of Mecosarthron Buquet and Xixuthrus Thomson and reevaluation of generic assignment of Xixuthrus domingoenis by Antonio Santos-Silva and Steve Lingafelter

M
orphological
analysis
of
M
ecosarthron
B
uquet
and
X
i
X
uthrus
t
ho
M
son
and
r
eevaluation
of
g
eneric
a
ssign
M
ent
of
X
i
X
uthrus
do
M
ingoensis
f
isher
(
c
oleoptera
,
c
era
MB
ycidae
,
p
rioninae
)

The world largest beetles

Titanus giganteus and Megasoma actaeon are considered the heaviest beetles (Williams 2001), and a male specimen ofTitanus giganteus having a body length of 167 mm the longest beetle of the world (Williams 2001). 

 

Two other candidates for the longest beetles are Macrodontia cervicornis (169 mm, own observation in collection J.Sticher, Germany) and Dynastes hercules. Large males of the latter may reach a body length of 170 mm, however, there is no confirmed record in the literature.

Large males of Batocera wallacei are distinguished by with impressively long antennae (max. length incl. antennae 315 mm, Raymond Chin, pers. comm.), and of Euchirus longimanus andAcrocinus longimanus extraordinarily prolonged forelegs.


Most exaggerated morphologies (such as prolonged mandibles, horns, antennae and legs) are found in male beetles, which use these structures in intra-specific fights.

 

Larger males have larger weapons in respect to their body length and win more often in direct encounters. A smaller male loosing in competition is not able to contribute genetic information to the population’s gene pool, unless it develops a alternative tactic to reproduce. Such tactics may be the reason why we still encounter distinct small male caste in species with prolonged morphological structures.