How to tell if a wide horn hisser is full-grown?

[Forcep]

I newly started a wide horn hisser colony with medium to large nymphs. Now more and more nymphs have lost their juvenile color pattern (4 white squares on their black cuticle ), but their size is not bigger than regular hissers at all... Below is the photo of my largest male so far

Well it is smaller than my largest regular hisser. Is it a sub-adult or adult? I hope they are still growing

 

[Keith]

Looks like it might be smaller, since no white it looks mature but wait and see who knows.

 

[Thomas]

I would say that, from my experience with hissers (limited to G. portentosa), this is a mature male.

 

[Forcep]

Good news: I've now got a huge sub-adult... There are really some variances going on this species.