I've kept records of all my Strategus, Dynastes, Phileurus and Lucanus species. I record things like when eggs were layed, hatching, weekly and monthly weights, L2 L3 pupae and emerging dates, deaths, diseases, breeding, etc.
All of this info can be very valuable. For instance, I noticed that with my Phileurus truncatus that on average the females weighed more than the males by 1-3 grams. I'd have many females in the 13-14gram range while males were in the 10-12 gram range. I sexed them by looking for that dot on the abdomen. Now that they are starting to emerge I can confirm the sex of each specimen.