I haven’t had a successful experience with Strategus antaeus (Drury) in captivity. I found couple of males and females, I set them up in a plastic container with substrate (depth of over 6 inches), but no eggs ever found. This year, I looked up a little (a little, because there is no info available anywhere) while collecting and studied the habitat where I collected the series of specimens. Then on one day, I read somewhere that S. antaeus requires sandy soil mixtures with plant materials, like grass roots or dead grass, and such, which gave me an interesting impression because there are some Ruteline and Cetoniine species requiring the same environment.
Set up on 26 May 2018
I found two males and one female on May 12th, 2018 at Natchitoches Parish of Louisiana. My set up was similar to that I explained above the images, except no grass. Having grass sounds too messy, and I don’t like it. Instead, I added some peat moss (moss that you overlay on top of a garden or a flower pot). Moss soaked in water overnight has been squeezed before placing over the soil mixture of 2 : 1 : 1 of sand : substrate : organic potting mix (here, I used Miracle-Gro Organic Potting Mix). I didn’t mix the moss with soil on purpose, hoping to see a female grab a piece and burrow. Such plant materials are used by females to protect eggs while laying in underground.
I found two eggs and three L1 larvae today, on August 7th, 2018 (after over 10 weeks). I believe these are quite fresh ones. I don’t know what made the female to decide to just start laying eggs, and not in couple of months ago.
Since it was rather a rare opportunity to find larvae and eggs of Strategus antaeus (Drury), I took some time observing them. An interesting factor of larvae is that they “crawl,” unlike many other dynastine scarab beetles. This kind of crawling can be observed from other scarab groups like Rutelinae or Melolonthinae. If the larvae crawl with its back, then usually, Cetoniinae. I haven’t seen any Dynastine larvae crawl like in the picture, and two dark colored larvae were doing the same thing. White one seems to be a very fresh one, not yet even started to feed. Two eggs found had a slight trace of larvae inside, if you take a closer look (hatched on around August 9-11th). The Size of eggs was quite surprising as they were larger than eggs of Strategus aloeus (Linnaeus) (in naked eyes), which is larger sister species, also occurring in Louisiana. A length of an egg (in the picture below, with scale bar of 2mm) is 4.66 mm long (major axis) and 3.63 mm wide (minor axis).