If you’re new to beetle breeding, here’s a quick guide to help you understand some of the basic terms and stages in their development. Check the photos for reference.
🔎 In stag beetles, the labrum is concealed under the clypeus and isn’t visible.
It’s somewhat important to make this distinction, as the clypeus often plays a key role in species identification.
📌 Stag beetle Anatomy
📌 Rhino beetle Anatomy
📌 Male genital
📌 Beetle larvae Anatomy
📌 Eggs
📌 Rhino beetle eggs / L1 / L2
✅ Larval Stages (Molting Stages)
L1 = 1st instar
L2 = 2nd instar
L3 = 3rd instar
📌 Rhino beetle Late L3
🔎 As the larvae get closer to metamorphosis into pupae, they turn yellow.
This is called Late L3.
✅ Pupal Chamber / Cocoons
Larvae build a pupal chamber (or cocoon) in the substrate to safely transition into pupae and eventually emerge as adults.
✅ Prepupal Stage
(Photo courtesy of @lucas_beetles)
This is the stage just before pupation. The larva stops feeding and starts to form its pupal chamber.
📌 Pupa
✅ Artificial Pupal Chamber (Oasis Foam Type)
You can make a pupal chamber using Oasis floral foam.
📌 Important: Only move the larva once it has fully entered the prepupal stage (meaning it can no longer move its legs or jaws), or after it has pupated.
📌 Pupa that emerges into Adult beetle
✅ Full Life Cycle
Egg → L1 → L2 → L3 → Pupa → Adult
✅ Inactive Periods (After Emergence)
Once a beetle has emerged (eclosed) as an adult, it enters an inactive period inside the pupal chamber or cocoon.
During this time, they don’t eat or move much.
Duration varies by species, usually 1–2 months, but for some, it can last 6 months or longer.
📌 Goliath beetles in active state.
🔎 Once the inactive period is over,
They start eating food.
✅ Maturity Period
After emerging and going through the inactive phase, most beetles need about 1–2 months of feeding before they’re ready to mate.
So in total, you’re usually looking at 2–3 months after pupation before successful pairing is possible.
🔍 Even within the same species, larger beetles often take longer to mature.
So give them time and don’t rush it, patience pays off.
✅ Mating (Pairing)
There are a few ways to pair beetles, but for medium to large stag beetles, it’s recommended to zip-tie the male’s jaws during pairing to prevent injury to the female.
✅ Generation Notation (How to Read Breeding Lines)
🔎 These notations help track bloodlines and maintain healthy diversity in breeding projects.
📌 WD = Wild Caught
📌 WF1 = Offspring of a wild pair
→ The next generation would be F2
📌 CBF1 = Offspring of two different captive lines (cross-breeding)
📌 F2, F3... = Subsequent generations from WF1 or CBF1 parents