lucanidae please i.d. roach

bugmankeith

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I caught more roach nymphs, this time I caught a bigger one, and you can compare it to the smaller one, which looks like the one I caught in the other thread. These look like wood roaches to me...as did my other one, but you take a stab at their i.d I currently have them in a moist enclosure with food and dirt.

 

lucanidae

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I am no roach expert, but I have keyed out the common families native to NY. I could never give a definite ID from a picture like that, I'll look at some keys and then I can tell you what features to look for... I know the genital configuration will be a factor in determining the genus. Also, you can't garuntee that those two are the same sp. nor can you garuntee that any others you have caught previously are the same species. At best you can that picture is that these are either Wood Roaches or American Roaches; which look similar to each other.
 

lucanidae

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Taking a closer look I would guess (based on the width of the pronotum) that the larger one in that picture is a Wood Roach and the smaller is an American Roach. Were they collected in the exact same location (just wondering, the two sp. could cohabitate.)

Raising the smaller one another instar or two to see if the second thoracic segment grows over to cover the third will help to determine what species it is.
 

bugmankeith

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Yes they were, all the smaller ones looked like the small one, and the big all resembled the big.
 

bugmankeith

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I actually just figured this out myself, looking at enlarged photos of wood and american cockroach nymphs, I can tell all of mine were wood roaches. Beetween the cerci is where to look, in wood roaches there is one point, but in american roaches there is two, this applies for all nymph stages. Mine have one point, thus they are wood roaches, not american.

I knew it was too good to be true, I was looking foward to breeding american roaches too. :D

Found at:
http://www.ento.okstate.edu/4H-FFA/Blattaria.htm
 
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lucanidae

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From Borror and Delong's "Study of Insects" 7th edition. The way to determine between Blattidae (American roach in this case) and Blattellidae (Wood roach in this case)

Blattidae

"Female subgenital plate divided longitudinally; male styli similar, slender, elongate, and straight. lenth of 18 mm or more"

Blattellidae

"Female subgenital plate entire, not divide longitudinally, male styli vatriable, often modified, asymmetrical, or unequal in size. Length variable but usually less than 18 mm"

I knew it had something to do with the genetalia.

Also from Borror and Delong 7th edition: on Wood roaches

"Pacoblatta spp., which live in litter and debris in the woods; most species in this group occur in the South, where they may be found in the litter and debris..."

Looking between the ceri I would have to agree on Wood roach, but I can't find anything in the key that uses that feature, which means it may be variable across species within genuses and families. Since we can't be sure which family your roaches belong to without looking at the genetalia, we can't use that feature to determine species.
 

bugmankeith

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Well anyway you have helped alot, but i'm going to let them go. Like I said last time I tried keeping them they didnt do so well, so soon they will be free. :)
 

lucanidae

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You should try to find an adult so you can look at the genetalia and get a postitive ID!
 

bugmankeith

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I have never seen any adults, isnt that weird? And I have collected these roaches for 3 years or more, but always let them go because they did poor in captivity.
 

lucanidae

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Raise the nymphs on rotting wood in a cooler environment with medium humidity and you should get some adults eventually. And yes it is strange not to have found any adults.
 

lucanidae

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And I must say I'm glad they didn't turn out to be B. lateralis because that would be trouble.........
 

bugmankeith

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Yeah true...

I would but im not really into raising them, i've kept them before and didnt only have trouble with temperature, but with eating, and them escaping. I have had a few escape, and since I only have 2 if any escape i will have none, they are quite rare where I found them, i'm lucky I found any. I do wish i found adults, mabye they dont live under wood, but in live tree trunks? If they have wings the males can fly, so i've read...

Mine are probably pennsylvania wood roaches, look them up and compare, they match perfectly.
 

lucanidae

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Looks good, of course Parcoblatta pennsylvanica is the only wood roach species whose range gets close to NY, so one would assume that if it is a Parcoblatta it would be pennsylvanica.
 

bugmankeith

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With no picture, at least I didnt say it was a hissing roach. :p lol at least its not the invasive species, you cant rest easily tonight.
 

bugmankeith

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Before I could let the roaches go the large roach suddenly died, I noticed something emerging from it's abdomen, a parasitic wasp larvae, which soon pupated. Never knew wasps go after cockroaches. The smaller roach was unaffected so I let it go back where I found it.
 

Jesse607

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The larger roach on the left looks to me like an adult female Parcoblatta spp. Most Parcoblatta females have brachypterous wings. The photo is a tad blurry to tell for sure, but they look a little too big to be just wing buds.
 
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