Synonyms and other taxonomic changes
Ischnoptera Fox 1917, Platamodes Scudder 1862
♂ up to 25 mm, ♀ up to 19 mm
in males, wings cover the abdomen; adult females typically have small wingpads (tegmina). Older nymphs may also have prominent wingbuds. Nymphs of different spp. are impossible to tell apart based on known characters; 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:
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.
P. americana: w. US (OR-CA-NM) & Mexico
P. bolliana: US
P. caudelli: VA-SC to IN-AR-TX
P. desertae: TX
P. divisa: US
P. fulvescens: e. US
P. lata: e. US
P. notha: AZ
P. pennsylvanica: e. US + QC-ON
P. uhleriana: e. US
P. virginica: e. US
P. zebra: IN-IL, TN-MS-TX
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-Jun)
males come to lights, and may accumulate in rain gutters of homes
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
indoors, they wander aimlessly during the day (rather than congregating in a particular room and being active at night), do not breed, and will die within a few days due to insufficient moisture.