.
Scarabaeoidea of Southern South America Links |
| |
|
|
|
| |
| .. |
Scarab Guide Links
(goes to the University of Nebraska
web site) |
.
Classification |
|
|
| ...... |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| ... |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| .. |
| ... |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| . |
| .. |
| . |
| . |
| . |
| . |
| . |
| . |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
|
|
| |
.
Brachysternus germaini (Ohaus, 1909)
Tribostethes germaini Ohaus 1909:9, 14. |
| |
| |
|
Figure 29a-c. Form of the male genitalia in Brachysternus germaini (lateral view of
parameres and apex of phallobase, caudal view of parameres, and ventral view of ventral
and lateral sclerites). |
| |
|
Map showing the distribution of B. germaini. |
|
| |
...... |
|
Description. Length: 19.5-20.3 mm. Width: 8.3-10.3 mm at base of elytra. Color:
Dorsally shiny apple green to olive green; eltyral margins metallic brassy green or green;
apex of clypeus castaneous (females) or green (males); pronotal margin testaceous suffused
with green or green; legs, sternites, pygidium, and propygidium coppery-brown to
castaenous. Head: Clypeal apex rectangular with broadly rounded corners, not constricted
at base; margins and apex weakly to moderately reflexed. Frons moderately densely
punctate (occasionally confluent at apex); punctures moderate to moderately large; setae
short to moderately long, hair-like, tawny to reddish; region posterior to eye with or
without sparse, thickened, short, white setae. Clypeus densely punctate (disc) and confluently
punctate (base and apex); punctures moderate to moderately large. Interocular
width 4.6-5.4 (male) or 4.8-7.2 (female) transverse eye diameters. Maxilla with terminal
segment of maxillary palpus (dorsally) deeply impressed from base to apex,
segment 1.4 (male) or 1.3 (female) times longer than segments 2 and 3. Antennal club
subequal in length to segments 1-7 (male) or segments 2-7 (female). Pronotum: Surface
with weakly impressed, median, longitudinal groove; disc moderately densely to densely
punctate (occasionally confluent), margins sparsely to moderately densely punctate;
punctures moderate to large, few setose at posteriolateral angle and anteriolateral angle;
setae hair-like and thickened, moderately long, tawny. Basal bead complete to just beyond
posteriolateral angle. Elytron: Surface with 1-5 poorly defined, punctate, longitudinal
striae between suture and humerus; punctures moderate and small (mixed), sparse
(disc), lacking setae. Intervals with similar sculpturing. Humeral umbone poorly developed,
apical umbone poorly developed. Epipleuron flat, not expanded, marginal bead
present; region from metacoxa to apex setose; setae thickened, short and moderately long (mixed), dense, whitish. Sutural angle square. Propygidium: Posterior margin with fringe
of setae; setae thickened, short, white. Supraspiracular ridge poorly defined. Pygidium:
Male: disc and middle apex with hair-like setae (moderately long and long [mixed],
moderately dense, white) and punctures (small, moderately dense); margins and base
with moderately dense, white, thickened setae. Female: disc lacking concavity, punctate;
punctures crescent-shaped (moderately dense) and transversely wrinkled, setose; setae
on hair-like and thickened, white, moderately long and long (mixed). Venter: Sternum
densely (male) or moderately densely (female) clothed with long, tawny, setae; sternites
with setae moderately dense, hair-like, white setae (less dense in female). Prosternal keel
broadly triangular; apex projecting anteriorly at about 458 with respect to ventral plane;
apex produced to about middle of protrochanter, blunt. Mesometasternum with apex
rounded or weakly quadrate, not produced. Apex of terminal sternite in female moderately
emarginated at middle. Legs: Larger protarsal claw of male with or
without weak nib at apex. Claws of female simple, subequal in width.
Tarsomere 5 without ventromedial tooth. Metatibia with inner and outer
edges straight, with carinae: 1 at middle, 1 in apical third, carinae more developed in
females; apical 1/5 weakly divergent (more so in females). Male genitalia: Fig. 29a-c. |
| |
|
|
Diagnosis. This species is separated from all other species in the genus
Brachysternus by the following combination of characters that are unique for
the genus: all tarsal claws appearing simple in male and female (male with weak, apical nib in some specimens); protarsomere 5 without
ventromedial tooth; pygidium of the female simple (lacking
discal concavity); terminal segment of the maxillary palp with deeply
impressed sulcus from base to apex; and 1.3-1.4 times as long as segments 2
and 3 combined (male and female). |
| |
|
|
Distribution (see map). Andes from Curicó to Concepción, Chile. |
| . |
|
| |
Locality Data. 9 specimens examined from BMNH, CMNC, CNCI, FMNH,
MNNC.
CHILE (9). CONCEPCION (3): Concepción, Penco. CURICO (2): El Coigo,
no data. LINARES (1): Estero Leiva, Cord Parral. NUBLE (1): Cachapoal.
TALCA (2): Canelillos (E. Carrizal), La Vega (E. Carrizal). |
| |
|
| |
Temporal Data. February (1), October (1), November (4), December (3). |
| |
|
| |
Remarks. Brachysternus germaini has an unusual combination of primitive
and derived character states compared to other species of Brachysternus. Some
character state reversals include: all tarsal claws appearing simple in both sexes
(shared with Hylamorpha), sulcate terminal maxillary palp that
is longer than the two preceding segments (shared with some species of Aulacopalpus), pygidium in the female that lacks a discal concavity
(shared with some species of Aulacopalpus), supraspiracular ridge not welldeveloped
(shared with species of Aulacopalpus), and fifth protarsomere that
lacks a ventromedial tooth (shared with species of Aulacopalpus). In addition, B. germaini shares many derived character states with other
species of Brachysternus including: form of the maxillary teeth,
male parameres with well developed lateral and ventral sclerites (Fig. 29a-c),
and apex of the terminal sternite moderately emarginate in the female. Transfer of this species from Aulacopalpus to Brachysternus is justified
based on these derived character states. Smith's (2002) phylogenetic analysis
of the subtribe Brachysternina also corroborates transfer of this species to
Brachysternus. Although Brachysternus germaini has been collected in several
Chilean provinces, it is rare in collections. |
| |
|
| |
Literature cited:
Smith, A. B. T. 2002. Revision of the southern South American endemic genus Aulacopalpus Guérin-Méneville with phylogenetic and biogeographic analyses of the
subtribe Brachysternina (Coleoptera: Scarabaeidae: Rutelinae: Anoplognathini).
Coleopterists Bulletin 56:379-437. |
| |
|
| |
Excerpt from:
Jameson, M. L. and A. B. T. Smith. 2002. Revision of the South American genus Brachysternus Guérin-Ménville (Coleoptera: Ruteliinae: Anoplognathini: Brachysternina). Coleopterists Bulletin 56: 321-366. |
| |
|
