50th Post!: Tinley Park NARBC Expo

[stanislas]

I've good news regarding this issue: There is a Chinese article that describes how one can distinguish P. obscura from P. saussurei. 
"Study on the morphology and internal structures of Polyphaga obscura Chopart" (http://europepmc.org/abstract/CBA/297263)

I've manages to get the complete article, and my Chinese colleague has read it for me. 
Basically, the ootheca differ. The ootheca teeth differ: 
Polyphage saussurei has more spaced teeth (the article describes the space between the teeth > 1/2 width of the teeth): 

(source image: http://www.cic-net.co.jp/blog/cat6/polyphaga_saussurei/)

Polyphaga obscura: teeth closer together (article describes this as space between teeth < 1/2 width teeth): 

(source image: http://www.cic-net.co.jp/blog/cat6/polyphaga_obscura/)

I have both Polyphaga saussurei and obscura. But the P. obscura are still small, so I cannot compare yet.
My P. saussurei roaches are indeed very shiny: 

 

[Hisserdude]

I've good news regarding this issue: There is a Chinese article that describes how one can distinguish P. obscura from P. saussurei. 
"Study on the morphology and internal structures of Polyphaga obscura Chopart" (http://europepmc.org/abstract/CBA/297263)

I've manages to get the complete article, and my Chinese colleague has read it for me. 
Basically, the ootheca differ. The ootheca teeth differ: 
Polyphage saussurei has more spaced teeth (the article describes the space between the teeth > 1/2 width of the teeth): 

(source image: http://www.cic-net.co.jp/blog/cat6/polyphaga_saussurei/)

Polyphaga obscura: teeth closer together (article describes this as space between teeth < 1/2 width teeth): 

(source image: http://www.cic-net.co.jp/blog/cat6/polyphaga_obscura/)

I have both Polyphaga saussurei and obscura. But the P. obscura are still small, so I cannot compare yet.
My P. saussurei roaches are indeed very shiny: 

View attachment 1481

Very interesting, thank you very much for the information! Interesting how the oothecae can be used to differentiate the two. So it looks like there really are both species in the hobby, hopefully some US breeders will be able to get their hands on some P.obscura soon!