Distribution of the American milliped genus Boraria Chamberlin, 1943: Introductions of B. stricta (Brölemann, 1896) in New York and B infesta (Chamberlin, 1918) in Connecticut; indigenous occurrence of B profuga (Causey, 1955) in Louisiana (Diplopoda: Polydesmida: Xystodesmidae).
Author
Shelley, Rowland M.
Author
McAllister, Chris T.
Author
Nagy, Christopher M.
Author
Weckel, Mark E.
Author
Christie, Roderick G.
Author
Wilson, Paul
Author
Wilson, Allan
text
Insecta Mundi
2011
2011-09-16
2011
194
1
8
journal article
10.5281/zenodo.5161267
1942-1354
5161267
Boraria stricta
(
Brölemann, 1896
)
(
Fig. 1-2
, 5)
Distribution
.
Boraria stricta
, the only representative in
South Carolina
and
Georgia
, occupies a large, continuous area with one and perhaps two proximate allopatric populations and a distant introduced one. The continuous area extends, north/south, from northern Floyd Co.,
Virginia
, to northern Lumpkin Co.,
Georgia
; east-west, it ranges from the western Piedmont Plateau of
North Carolina
(Wilkes, Burke, and Rutherford counties) and the westcentral Piedmont of
South Carolina
(Union and Spartanburg counties) to the western periphery of the Blue Ridge Province in
Virginia
and
Tennessee
(Fig. 13). The milliped has not been encountered in
Tennessee
south of the GSMNP, so the area encloses the indigenous occurrences of both
B. infesta
and
B. deturkiana
except for the Monroe Co.,
Tennessee
, locality of the former. In addition to the allopatric population in the Kings/Crowders Mountains Inselberg, the Bland Co. locality, around
48 km
(
30 mi
) west of the main area, may represent such in
Virginia
. This record establishes the genus and species in the Ridge and Valley Physiographic Province and suggests occur- rence in the Appalachian Plateaus Province (Allegheny Mountains) in southern
West Virginia
, only
9.6 km
(
6 mi
) to the northwest (Fig. 12-13).
Figures 1-4.
Boraria
spp.
1
)
A cluster of
B. stricta
under leaves on saturated substrate at Mianus River Gorge Preserve, Westchester Co., New York.
2)
An individual of
B. stricta
climbing a log at this site; note the juvenile in the depression left of center.
3)
A tributary of the Mianus River in the Preserve showing leaf litter and the surrounding deciduous forest, an ideal environment for
B. stricta
.
4)
B. infesta
from Avon, Hartford Co., Connecticut.
The
New York
population, some
704 km
(
440 mi
) to the north-northeast (Fig. 12), constitutes the first record of
B. stricta
outside the general southern Appalachian region. In the 115 years since its description (
Brölemann 1896
), copious samplings in suitable environments to the north in
Virginia
,
Maryland
,
Pennsylvania
, and
New York
have not yielded a single individual of
B. stricta
, so its occurrence in Mianus River Gorge Preserve (MRGP) can only be interpreted as a rare, intra-continental, human aided introduction that has established a reproducing population.
Published records.
Virginia
:
Floyd, Franklin
,
Grayson
, and
Patrick counties
(
Chamberlin and Hoffman 1958
;
Hoffman 1965
,
1999
).
Tennessee
:
Blount, Greene, Johnson,
and
Sevier counties
(
Chamberlin and Hoffman 1958
,
Hoffman 1965
).
North
Carolina
:
Alexander, Ashe, Avery, Buncombe, Burke, Caldwell, Clay, Cleveland, Gaston, Graham, Haywood, Henderson, Jackson
,
Macon
,
Madison, Mitchell, Rutherford, Swain
,
Transylvania
,
Watauga
,
Wilkes
, and
Yancey counties
(
Chamberlin and Hoffman 1958
;
Hoffman 1965
,
1999
;
Filka and Shelley 1980
,
Shelley 2000
).
South
Carolina
:
Oconee
and
York
counties
(
Hoffman 1965
,
Filka and Shelley 1980
).
Georgia
:
Dawson
and
Rabun counties
(
Chamberlin and Hoffman 1958
;
Hoffman 1965
,
1999
).
New records.
Virginia
:
Bland Co
.,
2.4 km
(
1.5 mi
S Suiter, M,
26 April 1980
, D.W. Ogle (VMNH).
Floyd Co
., Twin Falls,
2.6 km
(
1.6 mi
) W Copper Hill, M,
2 July 1974
, D. Surface (VMNH).
Tennessee
:
Cocke Co
., Great Smoky Mountains National Park (GSMNP), Cosby Picnic Area, M,
19 June 1976
, R.M. Shelley (NCSM).
Sevier Co
., GSMNP, Roaring Fork Motor Nature Loop near Gatlinburg, M,
19 June 1976
, R.M. Shelley (NCSM).
South
Carolina
:
Spartanburg Co
., Croft State Park, M,
20 August 1976
, R.M. Shelley (NCSM).
Union Co
.,
10.2 km
(
6.4 mi
) NW Union, F,
2 May 1977
, R.M. Shelley (NCSM).
Georgia
:
Dawson Co
.
,
Amicalola Falls State Park
, 2M,
16 April 1978
,
R
.
M. Shelley
,
R
.
E. Ashton
(
NCSM
).
Habersham Co
.
,
Tallulah Falls
, M
,
April 1891
,
L.M. Underwood
(
USNM
)
;
and
Cornelia, M
,
11 July 1978
,
R
.
M. Shelley
,
W.B. Jones
(
NCSM
).
Lumpkin Co
.
,
15.4 km
(
9.6 mi
)
NE Dahlonega
, 3M, 3 juvs.,
16 April 1978
,
R
.
M. Shelley
,
R
.
E. Ashton
(
NCSM
)
.
New York
:
Westchester Co
.,
Bedford
, MRGP (
41
o
11’ 11.5”N
,
73
o
37’ 15.4”W
), 10M, 9F, 2 juvs.,
30 April 2010
, C. Nagy (NCSM, FSCA).
Introduced Population, New State Record.
Remarks.
The apically subhastate gonopods (Fig. 5), coupled with the bimaculate, yellow/black color pattern and the relatively narrow body proportions (
Fig. 1-2
) distinguish
B. stricta
from congeneric species and sympatric xystodesmids. It inhabits deciduous leaf litter and typical xystodesmid environments (
Shelley 1981
,
Shelley and Whitehead 1986
) but is unique in tolerating saturated, muddy/mucky biotopes (
Fig. 3
) even with small amounts of standing water.
Hoffman (1965)
characterized
B. stricta
as “more nearly semiaquatic than any other milliped I know,” and a likely spot to encounter it is on or beside a trail at a stream/creek crossing (
Hoffman 1950
, personal observations of RMS).
Mianus River Gorge Preserve (http://www.mianus.org/) is located approximately
1.6 km
(1.0 mi) south of
Bedford
,
New York
,
41.6 km
(
26 mi
) northeast of the Bronx, and
24 km
(
15 mi
) north-northwest of Stamford,
Connecticut
. In 2000, a xystodesmid with the color pattern and body proportions of
B. stricta
was first observed in the damp, cool gorge habitat, which consists primarily of post-agricultural oakhickory woodlands and old-growth eastern hemlock stands, and hence is similar to the milliped’s native Appalachian environments. Based on known distributions, the only xystodesmids expected in southern
New York
are
Apheloria virginiensis corrugata
(Wood, 1864)
,
Sigmoria
(
Rudiloria
)
trimaculata trimaculata
(Wood, 1864)
, and
Pleuroloma flavipes
Rafinesque, 1820
(
Bailey 1928
;
Blake 1931
;
Jacot 1938
;
Chamberlin 1940
;
Eaton 1943
;
Hoffman 1949
,
1951
,
1957
,
1999
;
Shelley 1980
;
Kevan 1983
;
Shelley and Whitehead 1986
), but the photo posted on the Bugguide website (http://bugguide.net/node/view/37) quickly eliminated the first two. With variable size and body proportions (
Shelley 1980
),
P. flavipes
was a possibility, so in summer 2009, CMN sent the Gorge sample to RMS, who recognized
B. stricta
, which constitutes its first record outside the southern Appalachian region, some
704 km
(
440 mi
) to the south-southwest. Residential yards in the Gorge neighborhood are extensively landscaped with ornamental gardens and nursery plants, the probable source of the original introduction. The Preserve was systematically surveyed for
B. stricta
in 2008-09 using the mustard solution method of
Hale (2007)
; density estimates of 4.1 + 13.9 individuals/m
2
(mean+ SD) throughout the area and 1.74 + 2.93 individuals/m
2
at streamside plots (via visual and cover searches) indicate rapid population growth after introduction, which was at least 11 years ago based on the aforementioned first sighting in MRGP. Searches at nearby preserves in Westchester Co. (Ward Pound Ridge, Westmoreland Sanctuary, Greenburgh Nature
Center
, Teatown Lake Reservation, and Cranberry Lake) and Greenwich Audubon, Fairfield Co.,
Connecticut
, have not yielded
B. stricta
. It is commonly found in moist conditions under logs and in streambeds in MRGP but also inhabits nonriparian hardwood uplands and old-growth eastern hemlock stands that are comparatively dry and virtually devoid of deciduous vegetation. Staff and student researchers at the Preserve are investigating the ecological impact of
B. stricta
on native species; monitoring this population and determining its extent in Westchester Co. constitute worthy projects for regional nature clubs and high school biology classes. Population ecology studies would also be productive.