A new species of Parochodaeus Nikolajev from the southwestern United States (Coleoptera: Scarabaeoidea: Ochodaeidae)
Author
Paulsen, M. J.
text
Insecta Mundi
2011
2011-05-27
2011
184
1
4
journal article
10.5281/zenodo.5161110
1942-1354
5161110
B74B457D-C63D-41AF-B954-3F39B83E11D9
Parochodaeus pixius
Paulsen
,
new species
(
Figures 2, 4
, 5)
Type material.
Holotype
male (
TAMU
) labeled: a) “
USA
:
TEXAS
: CULBERSON Co./ Pine Springs, UV light,
N31.877º
/
W104.825º
;
1763m
;
19.VIII.2006
/ MJ Paulsen, AD Smith, R Smith”; b) red
holotype
label “
Parochodaeus
/
pixius
Paulsen
♂
/
HOLOTYPE
”
.
Allotype
female (
TAMU
) labeled: a) as
holotype
; b) red
allotype
label “
Parochodaeus
/
pixius
Paulsen
♀
/
ALLOTYPE
”.
12 paratypes
deposited at
CMNC
,
FMNH
,
FSCA
,
MJPC
,
PKLC
,
UNSM
labeled: a) as
holotype
; b) yellow
paratype
label “
Parochodaeus
/
pixius
Paulsen
/
PARATYPE
”
.
Type
locality.
USA
:
Texas
: Culberson County: Pine Springs.
Description,
holotype
male.
Length
:
3.5 mm
.
Width
:
1.7 mm
.
Color
:
Reddish brown, shiny.
Head
:
Surface lacking tubercles or carinae, punctate; punctures fine to coarse, with short setae. Clypeus sub- trapezoidal, short (length equal to 1/5 width). Antennae with ten antennomeres. Mandibles rounded externally, apices acute and each with 1-2 peg-like internal teeth (
Fig. 4
). Mentum broadly concave for entire length (anteriorly emarginated in
P. biarmatus
).
Pronotum
:
Surface shiny, tuberculate, punctate between tubercles; tubercles weak, setose; punctures fine (
Fig. 2
), lacking setae.
Elytra
:
Surface shiny, slightly wrinkled. Striae with elongate, moderate punctures. Intervals with 2-3 irregular rows of small, setose tubercles; setae short, erect.
Legs
:
Metafemur with posterior margin entire (not toothed in distal half). Metatibia straight, narrow (>4× longer than wide) expanding gradually to apex.
Abdomen
:
Sternites 1-5 shiny, sparsely punctate in basal half only; punctures setose; setae decumbent. Sternite 6 more densely punctate. Posterolateral margin of sternites contiguous with pleurite, not expanded (sternites lacking lateral flange that contacts elytral margin as in ‘
P. biarmatus-
complex’). Stridulatory peg narrow, not strongly sclerotized.
Male genitalia
:
Internal sac with groups of small spinules only, lacking hooks, barbs, or serrate plates
sensu
Carlson (1975)
.
Figures 1-4.
Parochodaeus
spp.
1
)
Ventral view of left hindleg of
Parochodaeus biarmatus
.
Arrow indicating toothed posterior margin of the metatibiae.
2)
Pronotal punctation in
Parochodaeus pixius
n.sp.
, with fine punctures between the setae.
3)
Pronotal punctation in
Parochodaeus biarmatus
, with large punctures between the setae.
4)
Mandibles of
P. pixius
.
Description,
allotype
female.
Length
:
3.5 mm
.
Width
:
1.7 mm
. Differs from male
holotype
in the following external characters:
Head
:
Clypeus longer, length about equal to ¼ width.
Abdomen
:
Sternite 6 shiny, less densely punctate.
Description, variation in
paratypes
.
Length
:
2.6 – 4.0 mm.
Width
:
1.5 – 1.8 mm
. Differs from
holotype
in the following external characters:
Head
:
Mandibles occasionally with 1 inner tooth reduced.
Distribution.
UNITED STATES
:
TEXAS
: Culberson Co.: Pine Springs (13).
Temporal Distribution
. August (13).
Diagnosis.
Adults of
P. pixius
, although externally nondescript (Fig. 5), can be separated from the ‘
P. biarmatus-
complex’ by the lack of teeth on the hind margin of the metafemur and the fine, rather than coarse, punctures scattered between the setose punctures of the pronotum (
Fig. 2
). In addition,
the abdominal sternites lack the lateral flange that reaches the elytral margin as in
P. biarmatus
.
Etymology.
The name is a Latinized form of the English word ‘pixie’, meaning small, and is mascu- line in gender.
Remarks.
Specimens are known only from a single collecting event on HWY 62 near the
Guadalupe
Mountains. Two subsequent attempts to collect specimens at the same locality in
August 2010
produced none. I have not located additional specimens in other collections studied thus far, including most major North American collections. This argues that the species is either temporally or geographically restricted. If the species is geographically restricted to a small, relatively dry area with high seasonality it could suggest that adult activity is strongly influenced by recent precipitation events. As such, it is possible that the species may be active for only a short period and the timing of the 2006 collecting event was coincidental. However, this specificity is not found with most
Parochodaeus
species
, which are generally widespread and active from late spring until early fall. Another possibility is that the area sampled is not ideal and the actual habitat is located
Figure 5.
Dorsal habitus of
P. pixius
. Scale bar = within the nearby
Guadalupe
Mountains National
2 mm
. Inset with actual size of
Parochodaeus
spp.
from the
type
locality, from left:
P. pectoralis
,
P.
Park
, potentially at higher elevation. Due to the
biarmatus
, and
P. pixius
. park’s protected status, these higher elevations were not investigated and the species’ distribution within the park remains unknown. As for all other Nearctic ochodaeines larvae remain unknown.