New species, new records and synonymy of Mexican Corthylus Erichson, 1834 (Coleoptera: Curculionidae: Scolytinae)
Author
Atkinson, Thomas H.
text
Insecta Mundi
2020
2020-09-25
2020
792
1
25
journal article
7873
10.5281/zenodo.4564890
d9ee6109-a271-4440-8a93-dd53f043be8e
1942-1354
4564890
CF7B0E89-C497-408C-B359-B33939AB5C58
Corthylus microcorthyloides
Atkinson
,
new species
Fig. 15
Diagnosis.
This unusual species at first glance appears to be a species of
Microcorthylus
, especially because of its slender profile and the sulcate elytral declivity and small acute granules on interstriae 3. It differs from known species of that genus because the base of the pronotum has a fine raised lateral line. In most, possibly all species of
Microcorthylus
, the apices of the elytra are curved upwards and in direct posterior view the lower margin of the declivity is “v” shaped. In this species the apices are not upturned and the lower margin of the declivity forms a continuous curve. It could arguably be placed in that genus after revision of the character states that distinguish it from
Corthylus
. I have compared it to known species of
Microcorthylus
but it matches none of them. It would key to couplet
34 in
Wood’s 1982
key to
Corthylus
,
53 in
the 2007 key. In general appearance it most closely resembles
C
.
convexifrons
Wood.
Female.
Length:
1.6 mm
, maximum width:
0.9 mm
; length of elytra:
0.75 mm
; length to width: 2.1; elytral length/ total length: 0.56; elytral length/width: 1.20. (n = 1). Color yellowish brown, slightly darker on declivity.
Frons shining, flattened between eyes, weakly concave above epistoma to upper level of eyes; impunctate, without setae. A very faint longitudinal carina at upper level of eyes. Facets of compound eyes coarse, large in proportion to body size. Antennal club roughly oval, slightly asymmetrical. Short, erect, abundant setae distributed along entire perimeter of club, but not developed into a cirrus. Two straight sutures marked externally by shallow grooves, apparently not septate.
Anterior margin of pronotum unarmed. Anterior slope with rows of flattened asperities to summit. Disc smooth, shining, impunctate.
Elytra with discal striae and interstriae indistinct and confused at base, more distinct posteriorly with shallow punctures. Declivity abrupt in lateral profile, apex of elytra curved downwards. Interstriae 1 raised in a low costa; interstriae 2 impressed, impunctate. Interstriae 3 raised above level of 1 and 2, with 3 pointed denticles, each associated with a fine seta. Sparse, short setae also present on other posterolateral interstriae. Apical margin with a low, raised ridge, diverging from costal margin to about interstriae 7.
Male.
Unknown.
Type material.
Holotype
:
Mexico
:
Jalisco
, Mascota,
El Atajo, G.A
.
Quíroz R.
and
B.E. Díaz
M.,
2–31-X-2004
,
pitfall trap
(
NTP
trap) (
CNIN
).
Etymology.
The specific name refers to the overall appearance which resembles a species of
Microcorthylus
.