Monarthrum

Type species

Monarthrum chapuisi Kirsch

Adapted from Wood 1982, p. 1206-1245

Diagnosis

Monarthrum can be easily distinguished in this complex group by the 2-segmented funiclefunicle:
the antennal segments located between the scape and the club in some Coleoptera
and by the usually margined apicalapical:
situated at the apex or extreme outer edge of a structure or appendage
tip of the elytraelytra:
the two external and hardened or sclerotized forewings of adult Coleoptera, often appearing leather-like in texture
.

Description

Species in this genus range from 1.4 to 4.8 mm in length and are approximately 2.4 to 3.4 times as long as wide. Their color ranges from yellowish brown to very dark brown with many species being bicolored. The pronotumpronotum:
the upper or dorsal surface of the first thoracic segment
is longer than wide, asperateasperate:
of a surface or texture which is rough
anteriorly, and with the anterior margin serrate in males. The scutellumscutellum:
a shield-like bony plate or scale, as on the thorax of some insects
is large and flushed with the elytral surface. The declivitydeclivity:
the apical portion of the beetle elytra that slopes downward
is convex to concave, unarmedunarmed:
having no granules, teeth, tubercles, spines, or other protective structures
or armedarmed:
having a sclerotized surface structure, giving a rough texture; may serve as defense
by spines, and its apex varies from entire to emarginateemarginate:
notched or indented
. The metepisternummetepisternum:
the sclerite between the first and second lateral thoracic sutures
is only visible anteriorly. The vestiturevestiture:
a surface covering of scales or setae on the body, wing, or other appendage
is rarely present, if so, it is only at the declivitydeclivity:
the apical portion of the beetle elytra that slopes downward
. Some females have their fronsfrons:
the upper anterior portion of the head capsule
elaborately ornamentedornamented:
having markings or structures on the esclerotized regions of the integument, such as setae, tubercles, or granules
by hair-like setaehair-like setae:
setae that are thin and similar to a hair
. The anterior margin of the compound eye is emarginateemarginate:
notched or indented
. The scapescape:
the first and basal segment of the insect's antennae
is longer than the 2-segmented funiclefunicle:
the antennal segments located between the scape and the club in some Coleoptera
, and it is either slender or triangular, bearing long hairs in females of some species. The clubclub:
the apical segment of the insect antennae that is enlarged or thickened such that it is anatomically differentiated from the preceding segments
is relatively large and variable in shape with two straight to procurvedprocurved:
pertaining to structure (antennae, setae) which is basally perpendicular to the body and whose apical part is curved anteriorly
sutures usually present; its posterior faceposterior face:
the side not visible when the club is elevated against the head or visible when the club is down and sensing a surface; it usually has no sutures
is usually ornamentedornamented:
having markings or structures on the esclerotized regions of the integument, such as setae, tubercles, or granules
by long hair in females. The procoxaeprocoxae:
extra segment occasionally preceding coxa (hip joint) of the first or anterior pair of legs of arthropods
are contiguouscontiguous:
sharing an edge or boundary; touching
.

Distribution

United States to Argentina

World fauna

Number of species: 131, Native species: 5, Introduced species: 0

Hosts

Acer, Alexia, Alnus, Betuia, Brunellia, Carya, Castanea, Chrysolepsis, Clusia, Coffea, Erythrina, Fagus, Ficus, Inga, Liquidambar, Lithocarpus, Mimosa, Nectandra, Nyassa, Ochroma, Parkinsonia, Pinus, Podocarpus, Prunus, Spondias, Quercus, Tilia, Theobroma