Length of final instar

[Ralph]

My female hisser molted into a subadult two days ago. She is still a lot smaller than my adults, and I was wondering if the last instar takes longer or is more difficult. I've been feeding them regularly, and they are at maybe 75 degrees.

 

[Maarten..]

Are you certain she's subadult?

After molting they are shorter and wider. After feeding for a couple of days the abdomen gets more elongated. So the roach still has to 'grow'.

 

[Matt K]

Are you certain she's subadult? After molting they are shorter and wider. After feeding for a couple of days the abdomen gets more elongated. So the roach still has to 'grow'.

It is often difficult to tell which of the last few molts is the actual pre-adult molt. It really depends on how much that particular roach will grow. You would have to know exactly how many times that exact roach molted to get close.

 

[Ralph]

Actually, I'm not sure she and the two males that just molted are subadult. They have molted 5 times, so it looks like I misjudged their age. I have observed the shrinking just after a molt, and then expanding.