Genus Parcoblatta - Wood Cockroaches

Woods Cockroaches

Wood Roaches

genus Parcoblatta Hebard, 1917

synonym Ischnoptera Fox, 1917

synonym Platamodes Scudder, 1862

Type species: Blatta pennsylvanica De Geer, by subsequent designation

12 species within the genus Parcoblatta, all located in North America (Blattodea species file):

Parcoblatta americana (Scudder, 1900)

Parcoblatta bolliana (Saussure & Zehntner, 1893)

Parcoblatta caudelli Hebard, 1917

Parcoblatta desertae (Rehn & Hebard, 1909)

Parcoblatta divisa (Saussure & Zehntner, 1893)

Parcoblatta fulvescens (Saussure & Zehntner, 1893)

Parcoblatta lata (Brunner von Wattenwyl, 1865)

Parcoblatta notha (Rehn & Hebard, 1910)

Parcoblatta pennsylvanica (De Geer, 1773)

Parcoblatta uhleriana (Saussure, 1862)

Parcoblatta virginica (Brunner von Wattenwyl, 1865)

Parcoblatta zebra Hebard, 1917

male to 25 mm

female to 19 mm

Adult males in this genus have wings that cover the abdomen while adult females typically have small wingpads (tegmina) that are not capable of flight. Older nymphs may also have prominent wingbuds. Identification of Parcoblatta nymphs are not possible based on known characters, and identification of adult females is difficult or not possible, depending on the species and geographic location. Only the adult males have the characters that can definitively identify the species in this genus. Unfortunately, the characters needed are covered by wings, and so identification of living males is not usually possible.

Adult males and females of P. pennsylvanica and P. divisa have a dark brown pronotum with a pale, whitish border:

Male: Female:

The males of both species have a modification of the median segment that forms a ridge:

Males of P. pennsylvanica have a ridge on the median segment and a similar ridge on the first abdominal segment:

Adult male P. zebra have two ridges on the median segment. Contrast between the dark pronotum and the pale border is more subtle than in P. pennsylvanica and P. divisa.

Adult male P. uhleriana and P. fulvescens have a pair of structures on the median segment (and not the first abdominal segment). These structures do not meet in the midline to form a ridge. The wings are markedly broader than the pronotum in P. uhleriana, and only slightly broader in P. fulvescens. The small dark structures on median segment of this cockroach can be seen:

Adult male P. lata, P. notha and P. caudelli have paired structures on both the median segment and the first abdominal segment. P. lata is the largest and most commonly encountered of these three that are difficult to differentiate.

Adult male P. americana have a modification of the median segment that looks like a small square in the middle. This central spot on this specimen is hard to make out:

Adult male P. virginica have a patch of hair on the median segment that can be difficult to identify in photographs.

Unable to see patch of P. virginica at no magnification:

Patch on median segment at 200X magnification:

This makes P. virginica difficult to differentiate from P. desertaeand P. bolliana, notable for having not modification on the median segment. Size, geographic location, and other characteristics must be used to distinguish these three species if the presence of the patch of hairs cannot be clearly seen.

Widespread across much of North America.

Distribution of species as listed in Blattodea Species File

Parcoblatta americana: Oregon, California, Nevada, Arizina, Mexico

Parcoblatta bolliana: USA

Parcoblatta caudelli: Virginia, North Carolina, South Carolina, Indiana, Arkansas, Mississippi, Texas

Parcoblatta desertae: Texas

Parcoblatta divisa: USA

Parcoblatta fulvescens: Eastern USA

Parcoblatta lata: Eastern USA

Parcoblatta notha: Arizona

Parcoblatta pennsylvanica: Eastern USA, Quebec, Ontario

Parcoblatta uhleriana: Eastern USA

Parcoblatta virginica: Eastern USA

Parcoblatta zebra: Indiana, Illinois, Tennessee, Mississippi, Louisiana, Texas

hollow trees, stumps, under loose bark, wood piles, crevices of rural buildings; sometimes accidentally carried into homes on pieces of firewood, and may occasionally enter homes on their own in wooded areas, especially during mating season (May and June)

males are attracted to artificial light, and may accumulate in rain gutters of homes

adults from May to October

decaying organic matter

overwinters as a partially-grown nymph under bark of trees; life cycle usually takes one year but may take as long as two years; adult lifespan several months; mating occurs outdoors in May and June; an egg capsule (containing up to 32 eggs) is deposited in summer, eggs hatch in about a month, and nymphs mature the following May or June

Wood Roaches that enter homes wander aimlessly during the day (rather than congregating in a particular room and being active at night); they do not breed indoors, and will die within a few days due to insufficient moisture.

How to Know the Grasshoppers, Cockroaches, and Their Allies(1)

pinned adult image of female with egg capsule (Insects of Cedar Creek, Minnesota)

live nymph image of P. pennsylvanica (Steve Marshall, U. of Guelph, Ontario)

live adult image of female with egg capsule (U. of Michigan)

live adult image of male P. pennsylvanica (Tree of Life, courtesy U. of Nebraska at Lincoln)

adult illustration of male, plus description, biology, and control (William Lyon, Ohio State U.)

images of all life stages of P. pennsylvanica [courtesy U. of Nebraska] plus description, biology, and control (Pennsylvania State U.)

description, biology, behavior, and control (D.R. Suiter and P.G. Koehler, U. of Florida)