Virginia Wood Cockroach

Parcoblatta virginica (Brunner) (Plate IV, figures i to 5.)
1865. T[emnopteryx] virginica Brunner, Nouv. Syst. Blatt., p. 86. [9, Draper's Valley, Virginia.]
13= Accidentally recorded by Rehn and Hebard under iihlcriatia fulvesccns. 136 Previous to description incorrectly recorded by Caudell as uhleriana. Accidently recorded by Rehn and Hebard under uhleriana fiUvescens.
13^ Previous to description incorrectly recorded by Rehn as uhleriana.
138 Previous to description incorrectly recorded by Caudell as uhleriana.
139 Accidentally recorded by Rehn and Hebard under uhleriana fulvescens.
140 Previous to description incorrectly recorded by Caudell as uhleriana. Accidentally recorded by Rehn and Hebard under uhleriana julvescefis.
1865. I[schnoptera] borcalis Brunner,'-" Xou-. Syst. Blatt., p. 133. [d^. North America.]
The above synonymy is due to the fact that, at that time, the sexes of the species of the present genus in which the females have decidedly reduced tegmina, were supposed to represent distinct species, universally referred to different genera.
Males of this species are distinctive in the modification of the median segment and in the decided truncation of the supra-anal plate. In general appearance they are nearest males of P. iihleriana; which sex of these two species, among the medium small and normally pale forms of the genus, has exceptionally broad tegmina.
Proper association of the sexes of P. iihleriana and P. fulvescens, and the extensive series of those forms, as well as of the present species, now before us, leaves no room for doubt that the female, described by Brunner as T. virginica, represents that sex of the species the male of which was described, on a later page of the same work, as /. borealis.
As we now know, the female of uhleriana is very different from that of the present species."'Brunner's description of virginica could only be confused with fulvescens, but the females of that species average distinctly larger, are decidedly more robust and more frequently show wide differences in coloration. In addition we would state that, in virginica, the females normally hae the supra-anal plate with lateral margins straight, convergent to the more acute apex, the caudal margin of the sixth dorsal abdominal segment distinctly less convex and the large proximal spines of the cephalic margins of the cephalic femora fewer than in females of fulvescens.
The only other species of the genus, the known females of which have subquadrate tegmina,"^ is P. lata, an insect agreeing more closely with fulvescens, but much larger and more robust; under fulvescens full comparisons are made.
'^' A male of this species is also described on page 134, incorrectly as /. unicolor (Scudder). It is merely a specimen of recessive coloration, showing individual differences in the rami of the ulnar vein of the wings.
!■*See description under uhleriana.
'^' Females of Symploce lita Hebard, show a general resemblance to those of the present species, see page 151.
Characters of i/a/e.— (Asheville, North Carolina.) Size medium small for the genus, form moderately slender. Interocular space one-halfi" (to slightly less than) the width between the antennal sockets, (normally) appreciably less than the interocellar width. Ocelli well defined. Area between eyes and ocelli appreciably flattenedi" to a point just above the antennal sockets, with surface microscopically roughened. Maxillary palpi much as in P. bolliana. Pronotum with greatest width at mesal point, i« oblique sulci of disk very decided and connected caudad by a short, transverse impression. Tegmina and wings normal, fully developed ; tegmina broad, distinctly broader than pronotum, with point of greatest width meso-distad ; wings'(in the series) with two"' to five incomplete and four to six complete rami of the ulnar vein. Median segment with a moderately large mesal area supplied with minute scattered hairs. Other dorsal segments unspecialized, distal margin of sixth segment weakly and broadly convex in large mesal portion. Supra-anal plate transverse, truncate, fully four times as broad as long, weakly declivent distad, free margin weakly and briefly concave at bases of cerci, thence strongly convergent and weakly convex to broadly transverse median portion. Cerci slender, with (normally) ten"^ joints, decreasing evenly in size distad. Genital hook situated sinistrad! a chitinous process recurved at less than a right-angle, not as elongate as in hoUiana and in consequence normally concealed by the short supra-anal plate, least width at point of recurvature ; mesad and adjacent is situated a very slender and much longer, nearly straight, chitinous process with sharp apex directed slightly sinistrad. Subgenital plate roughly subquadrate with disto-lateral angles rounded, the rounding of the dextral angle slightly the broadest, the dextral margin is straight, produced to this angle, the sinistral margin is (normally) rather deeply concave just before the sinistro-distal angle, i" distal margin nearly straight, sub-oblique transverse; surface of plate weakly convex but rather extensively deplanate meso-distad; at the disto-lateral angles are situated, in sockets on the ventral surface of the plate at the free margin, simple, slender styles, similar in size and form, in length (normally) each equal to about three-fifths the distance between their bases, i^o Exposed portion of eighth dorsal abdominal segment, which is folded over the base of the subgenital plate, decidedly short, slightly shorter than exposed portion of seventh ventral abdominal segment.
1" This is the usual condition, though in this species frequent individuals show some difference.
'^5 Often weakly concave.
i« Occasional specimens have the greatest pronotal width very slightly caudad of the mesal point.
"'The type of Brunner's synonymous horealis is described as having but a single complete ramus. This is certainly attributable to individual variation.
i<8 Specimens with eleven distinct cereal joints are before us.
1" Slight variation in the free margins of the subgenital plate is frequent. The concavity of the sinistral margin, just before the sinistro-distal angle, is sometimes deep, rarely subobsolete. The distal margin often shows a slight concavity.
15" Slight variation in these appendages and in the distal diameter of the ]ilatc, results in occasional specimens showing styles with length of each onc-lialf to two-thirds the distance between their bases. Characters of Female. — (Collison Ridge, Bath County, X'irginia.) Size rather small, form more slender than in uhleriana or fiilve seen s, not as compact as in bolliana. Head broader and more evenly convex than in male. Interocular width slightly greater than that between antennal sockets. Minute ocellar spots present. Pronotum convex, without discal sulci, ample, with portion of greatest width near caudal margin, which is truncate, very weakly convex. Tegmina quadrate pads, with sutural margins slightly overlapping, extending slightly beyond caudal margin of median segment, rounding broadly at apex of anal vein and with the more broadly rounded angle at costal margin slightly the more produced, a slight emargination (normally!") indicated on the margin of the discoidal field; veins distinct. Wings represented by small atrophied pads, their apices extending slightly beyond the distal margin of the metanotum. Sixth dorsal abdominal segment with distal margin weakly and broadly convex in large mesal portion. Supra-anal plate decidedly more than twice as wide as long, lateral margins straight convergent, 1^2 from bases of cerci to acute, sharply rounded apex. Cerci shorter than in male, with lateral margins feebly crenate, joints distinct but dorsal. surface subdeplanate. Subgenital plate convex, little produced, with free margin rather weakly convex.
Measurements {in millimeters)
■^ Length of Length of Width of Length of Width of
^ body pronotum pronotum tegmen tegmen
Cambridge, Massachusetts (3) 13-13-9 31-3-2 3-7-3-9 15-15I 4-S-5
West Point, Xew
York (2) 1 1. 5-13. 8 2.7-3.2 3 -4-4 -I 14-3-16.6 4.6-5.6
Ivy Hill, Pennsylvania (9) 12.1-14.2 3-3.4 3-7-4-3 14-7-17 4-8-5-2
Washington, District
of Columbia (15) 11.7-13 3-1-3-3 3-^-4-3 I3-8-I5-7 4-6-4-7
Tappahannock, ""ir-
ginia (3) 11. 8-12 3-1-3-2 3-8-3-8 14-137 4-6-4-1
'^' As in the other species showing this type of tegmina, the proportions show frequent slight individual variation. Sometimes an appreciable elongation, sometimes a distinct narrowing, is found. At the free margin of the discoidal field variation frequently occurs, ranging from no emargination whatsoever, to a decided concavity, which gives the tegmina a strongly truncate form. This latter condition is normal in fulvescens from the eastern United States, though occasional specimens from that region show only a slight emargination.
It is evident that, though eastern material of virginica and fulvescens is normally different in this feature, it can only be used as of secondary importance. Valid characters such as form, pronotal dimensions, production of the sixth dorsal abdominal segment and form of supra-anal plate must be used in separating females of these species. Failure to recognize this has resulted in Rehn and Hebard's incorrectly recording small females of fulvescens, unusual in tegminal contour, as borealis, a synonym of virginica, from Goldsboro, North Carolina and IVIena, Arkansas.
'^Occasional specimens show a vcr>' weak concavity of these margins.
j-71 Length of Length of Width of Length of Width of
body pronotum pronotum tegmen tegmen
Asheville, North Carolina (40) 12. 7-13. 7 2.8-3 3-7-4 I4-4-I5-8 4-7-4-9
Northern Illinois. .. . 14.7 3.4 4.3 16.7 5.7 St. Louis, Missouri . . 12.8 3 3.7 13.8 4.7 South Bend, Nebraska(5) 13. 8-1 5. 4 3.3-3.6 4.1-4.4 14. 3-1 5. 8 4.9-5.2 Arkansas City, Kansas II. 7 2.9 3.6 12.8 4.3 WoUaston, Massachusetts 10.3 3.7 4.8 4.3 3.3
Ivy Hill, Pennsylvania (51) 10.9-12.5 3-2-3.7 4I-4-9 3-8-4-9 2.7-3.3
Washington, District
of Columbia (32) 10. 3-1 1.7 3.3-3.6 4.-4.6 4-44 2.8-3.1
Rabun County,
Georgia (2) 10.5-11.4 3.3-3.3 4.2 3-3-3-7 2.8-2.9
Opelika, Alabama. . . 10.3 3.2 4.4 3.7 2.8
Vigo County, Indiana (2) 10.8-11.6 3.2-3.4 4.4-4.7 4-3.8 2.8-3 South Bend, Nebraska(3) 10. 4-1 1.5 3.6-3.8 4.5-4.7 3.9-4.6 2.8-3.2
Rather decided size differences are shown by the very extensive series before us, these in great part due to individual variation, though over certain regions somewhat different averages are found to occur. No differences of adequate value or constancy are found, however, to warrant the recognition of a geographic race.
The average number of heavy spines on the ventro-cephalic margins of the cephalic femora aid in distinguishing virginica from Jtdvescens, and in consequence we have made the following counts from one hundred females^^^ from all portions of the series before us.
Number of Spines 2-4 3-3 3-4 4-4 4-5 4-6 5-5
Number of Specimens. ... 3 5 9 64 15 2 2
Of these, 64 % have four spines on each limb, 81 % four or less, while 98 % have four or less on at least one of the limbs. The fifth or sixth distal, heavy spine, when present in this species, is usually much smaller than the others.
Coloration. — cf . (Normal.) General coloration ochraceous-buff , with disk of pronotum slightly darker. Head tawny, eyes mummy brown, ocelli pale ochraceous-buff, mouth-parts ochraceous-buff".
"'^ This sex of these species is alone liable to be confused. In the males the spine count agrees closely with that of the females.

Parcoblatta virginica, the Virginia wood cockroach, is a small cockroach species of the genus Parcoblatta, measuring about a centimeter long as an adult.