Since the writing of this manual, significant improvements have been made
to key aspects of the rearing method for Goliathus, especially in
regard to the cell (cocoon) stage. Until this manual is updated with
revised information, please see Jonathan T. Lai's article
Then and Now: Last Piece of the Puzzle Found" in issue
#78 of the SCARABS newsletter (PDF).
Breeding/Rearing of Goliathus
By Karl Meier
version arranged by C. Campbell)
the permission of coleopterist Karl Meier (Germany), I have assembled the
following pictorial manual (with supplemental photographs from various
other hobbyists) in which he describes his captive breeding technique for
Goliath beetles. I extend my appreciation to Mr. Meier for making
his research available for viewing here at the GOLIATHUS website,
and also wish to thank hobbyists Matthias Frei (Switzerland), Fan Lin (Japan)
Bibitte for providing additional photos. I am certain
that many beetle hobbyists will benefit greatly from the techniques discussed
in this presentation.
You may also be interested
in reading the following articles contributed to my Family SCARABAEIDAE
website by hobbyist Yasuhiko Kasahara (Japan):
Breeding/Rearing of Prosopocoilus giraffa keisukei
Breeding/Rearing of Dynastes hercules hercules
Inhabitants of Africa's great equatorial forests and and sub-equatorial
savannas, the Goliath beetles (genus Goliathus) are among the largest
and most spectacular members of the family Scarabaeidae, and most certainly
the largest of the Cetoniinae (Flower scarabs).
The closest relatives of Goliathus are the genera Argyrophegges,
and Hegemus. In recent years, the captive breeding of Goliathus
has become more popular with beetle hobbyists as a better understanding
of the particular needs of these insects has been gained. Although
one of the more demanding cetoniine scarabs to rear, with some patience
and effort, it is certainly possible to maintain
pair of Goliathus goliatus (wild collected in Cameroon). The
male in this photo measures 10 cm (4 in.), which is at the upper limit
of the size this species generally attains. Photo
courtesy of Matthias
While it appears that relatively little is known about the exact biology
of these beetles in the wild, through considerable trial and error over
the past decade or so, an effective captive rearing procedure for this
genus has been established. Among the scarabs, Goliath beetles are
indeed unusual in their particular requirements, and the methods used for
rearing them differ from those of most of the other cetoniine species that
have long been in culture.
same male as shown in the above photo. This beetle weighs 42 grams.
courtesy of Matthias
Although it is usually rather easy to encourage gravid
females to deposit eggs, the captive reproduction of Goliathus beetles
was problematic until quite recently. The two key factors for successful
breeding were the discoveries that the larval stage needs to be provided
with a high protein diet on a consistent feeding schedule, and that the
pupal stage requires specific environmental conditions in order to avoid
high mortality rates and other complications.
2. Adults and egg production
For the purpose of egg-laying, a substrate composed of approximately 60%
hardwood (pulverized to a rather fine
particle size) and 40% organic,
content commercial potting soil (or alternatively, pure peat) works well.
Both of these components should be thoroughly mixed together until of uniform
A substrate of 100% rotten wood can be used if desired, although the addition
of peat is helpful in maintaining an even distribution of moisture throughout
the substrate. If peat is unavailable in your particular area, coconut
coir (a peat-like material made from pulverized coconut husks) can be substituted
for it. Some commercial brand names for this product are Lignocel,
Peat, and Bed-A-Beast. It is sold at pet stores and garden
centres in the form of compressed, dehydrated blocks which are then soaked
in a bucket of water until fully expanded. The material is then tightly
squeezed by hand to remove excess water.
suitable breeding substrate for Goliathus can be made by mixing
60% rotten deciduous hardwood (pulverized) with 40% quality, commercial
potting soil. Photo courtesy of Karl Meier.
The proper moisture level for Goliathus breeding substrate is the
same as that used for most other Cetoniinae. The substrate should
be moist, but not truly damp.
freshly emerged male G. goliatus which displays brilliant reddish
brown elytra (captive reared). Photo courtesy
If a handful of the material is squeezed tightly, and only sticks together
very momentarily upon being released, then it is probably at approximately
the right moistness. Another useful test for determining the substrate's
moisture level is to tightly pinch a small amount of it between your thumb
and forefinger. If a drop of water falls freely from it, then it
is certainly too damp. If water only appears slightly between the
fingers yet does not drip, the moisture is correct.
To ensure that you do not initially add too much water to the substrate,
begin by adding only a small amount. If it is still too dry after
thorough mixing, continue adding water in small increments until the substrate
reaches the desired moisture level. If your substrate material is
too wet from the start, or if you accidentally add too much water upon
mixing it, spread the materials out in a thin layer on a large plastic
sheet and place it in a sunny area until the excess moisture has been evaporated.