In order to save time replying to many similar questions, I wrote this brief guide for people who are just starting with beetles or are interested in starting with beetles. Please note that many conclusions on beetle keeping are drawn from my own personal experience with beetles; some people may see it differently:) I will try to keep upgrading this post in the future if I will come up with more useful information/suggestions.
In my opinion they are :
very unusual and often fascinating/spectacular looking insects,
most of them are quite easy too keep and raise to adults, so you can observe their development, which is amazing!
The beetle hobby is massively popular in some Asian countries such as Japan where beetles are sold in specialised shops or even supermarkets. Perhaps it is not so popular in other countries, but there is still quite a number of beetle hobbyists in Europe or USA. Most of the beetles are abundant in nature, however some of the species are in decline mainly due to human activities; e.g. many species are in substantial decline or even threatened due to massive deforestation on the African continent. Creating breeding pools of beetles in captivity will ensure that population of many species will be preserved. As some of your may already know, the collective expertise of beetle breeding enthusiasts allowed successful reproduction of some difficult species in captivity. E.g. Goliathus sp. breeding became possible only a few years ago after discovery that Goliathus larvae require high protein food for their successful development.
What species to start with?
3 most popular groups of beetles in breeding are:
a) flower (scarabs) beetles (family of scarab beetles, Scarabaeoidea; subfamily Cetoniinae; such as Pachnoda ssp, Dicronorrhina ssp, Mecynorrhina ssp, Goliathus ssp),
b) rhino beetles (family of scarab beetles, Scarabaeoidea; subfamily Dynastinae, such as Megasoma ssp or Dynastes ssp)
c) stag beetles (family such as Lucanus ssp or Dorcus ssp).
Some other beetles that people also keep are
d) darkling beetles (Tenebrionidae)
e) dung beetles (from subfamily Scarabaeinae)
f) ground predatory beetles (family Carabidae, such as tiger beetles (Cicindela ssp)
Flower beetles (apart from Goliathus sp. ) are the easiest group to keep, then rhino and stag beetles. Normally (people like me) like most exotic/bright/colourful/unusual looking beetles.
When you about to start, it is the best to research beforehand about the species of your choice, in case if they have any specific care conditions, and, if you can provide such conditions for them at your home. E.g. some beetles may require fermented wood for the growth of their larvae or higher temperatures for their habitat. The keeping ground and dung beetles could be complicated due to some specific requirements: the first often require lots of space in order to obtain any offspring, the second group needs lots of animal dung which often difficult to find especially in urban surrounding :(.
How many stages of development does beetle have?
Beetles have 4 stages of their life cycle:
(1) an egg; (2) a larva; (3) a pupa; (4) an adult beetle (imago)
The development of the larvae consist of 3 different stages/instars which are normally labelled as L1, L2, L3. Larvae shed their skin at the end of every stage, thus allowing an increase in size of their head capsule (which is hard and does not grow). At the end of L3 larvae molt into pupae, which then molt into adult beetles. Beetles then stay dormant/inactive for some time during which they complete their development. (see inactive period below)
The duration of various stages vary for different beetles and the whole cycle could be as short as 4-5 months in some flower beetles and as long as 3-4 years in some rhino beetles. In captive breeding, when larvae are supplied with rich in nutrients substrate and other conditions are optimal, the time of the development of the larvae is normally shorter than that.
What food does an adult beetle need?
Most of the adult beetles would eat any sweet ripe fruits, such as a pear or a banana. Ripe sweet banana is usually the best food due to its high protein and sugar content. However, in my experience some beetle species may prefer more watery fruits (at least from time to time), such as watermelon or pear, especially if the humidity in the beetle enclosure is low. Commercially available beetle jelly, which is mainly manufactured in Asia, is another great food source for adult beetles; its only drawback is its costs, especially if you have a big number of actively feeding adults. I regularly prepare loads of home made beetle jelly, which can be stored in the fridge for months. I posted a basic recipe for such jelly here http://beetlesaspets.blogspot.co.uk/2013/11/jelly-for-tropical-beetles-at-home.html
Please bear in mind that this is a basic recipe with plenty of room for improvisation with other food additives:) Some of the species may require more protein in their food and and if it is not provided, they may hunt and kill their own larvae if these are present in the same container.
What general conditions adult beetles require?
Different species may require slightly different conditions; however for the most popular beetle species these can be pretty much generalized. Firstly, adults need to be supplied with a sufficient amount of food, preferably all the time: this will significantly extend their life time. Please note that on rare occasions some adult beetles may not need any food, e.g. adults of European rhino beetle, Oryctes narsicornis, normally do not feed during their adult stage. Most of the beetles which live in tropical forests require high humidity conditions. This can be achieved by keeping them in the box with lid and some moist substrate in the box. A few small pen sized holes in the lid or top part of the side of the container will be sufficient for the air exchange.
Although the bigger the better, any small enclosure will be fine for beetles, especially if you are not planning to breed them. Please note, that males of some beetles, such as stag beetles, may injure other males or even females, especially if they are kept in a small(ish) enclosure. If you keep more than one beetle in the box it is important to make sure that there are some pieces of bark for them to hide and also branches and twigs for beetles to grab on, in case they fall on their backs.
What food do larvae need?
The food/substrate for the larvae perhaps is the most important thing in beetle breeding. Some larvae will not grow well or even die if the substrate is not appropriate or has a low nutritional value. For most beetle larvae substrate is normally derivative of decayed parts of deciduous trees, such as leaf litter or naturally decayed wood or artificially degraded wood such as fermented flake soil. Larvae of some beetles such as goliathus at their later stages, may require only high protein food, such as dog food pellets.
Here is a detailed post about the most common substrates used for beetle larvae.
It is important to know that larvae of some even closely related species, may have quite different substrate requirements. E.g. in my experience dynastes hercules hercules larvae at their later stages do not like a big percentage of decayed leaf litter in the substrate. In contrast, their close relative dynastes hercules lichyi may grow quite well in the same substrate. Unfortunately, the optimal substrate (or combination) often can be only obtained after a few tries, which may cost you a few larvae. The substrate or some of it is normally changed when a significant part is consumed by the larvae. Too much larvae waste in the substrate may lead to accumulation of poisonous gases which will negatively affect the development of the larvae. A similar thing often happens when too much organic supplement is added into the container, especially when the larvae are kept at higher (~25C) temperatures.
How to prepare a beetle breeding setup?
1) Flower beetles (apart from goliathus sp). Require a plastic box, with a lid, 2/3 full with loose soil with the addition of some mulched decayed wood and leaf material. With several bigger chunks of wood and twigs on the top for beetles to hang on and to hide, plus some leaves or peat moss as well. Leaves/peat moss on the top of the substrate will help to maintain the moisture in this level thus preventing beetle dehydration over longer periods of time. This is especially important if you keep the male and female in the breeding box, since the male normally spends most of the time on the surface of the substrate.
2) Rhino beetles and goliathus sp. Requre a plastic box filled with the soil of similar content to the flower beetles. The first 1/3 from the bottom of the box needs to be compressed by hand; females will normally lay their eggs into this layer. The middle third can be filled with lose soil finishing with chunks of the wood, twigs and leaves on the top.
Here is a detailed video how to prepare a breeding box for rhino beetles or goliath beetles. Please note that this video, due to convenience, shows me using a smallish 22l box, which will be good for a pair of small rhino beetles such as dynastes tityus or allomyrina dichotoma. In the case of bigger beetles a bigger box is needed.
3) Stag beetles. Require any smaller box with white rotten wood logs covered with soil or mulched wood-derived substrate or fermented wood. Again place some chunks of wood leaves and twigs on the top of the substrate for beetles to hide.
Other small but important things
What is F0 F1, F2, Fn...... generation?
Inbreeding within one population of species often leads to accumulation of many negative factors, such as susceptibility to diseases and decrease in size of the specimen. Wild caught specimen (assumed that they are not related, or captive bred unrelated parents) are normally marked as F0, their offspring as F1, and the offspring of F1 is F2 then. So technically the smaller the number after the F the better for the beetles and the breeder. I tend to mate unrelated beetles as often as I can.
How long do adult beetles live?
Many adult beetles live a relatively short time. E.g. dynastes granti may live for only a couple of months. Females often die once they finished oviposition. Bigger rhinos such as hercules or goliath may sometimes live for up to one year or sometimes even more, but normally the lifespan of an adult beetle is about 6 -+ 2 months. One of the longest living species in hobby is the Australian rainbow stag beetle: their males can live up to two years! It is important to understand, that because it's literally impossible to treat any beetle disease, some adults may die pretty young and unexpectedly. I had a cyclommatus metallifier male which lived for 15 months in my enclosure and I understand that it was wild caught, which may add another few months:), while normally these live only a few months.
Can larvae or adult beetles be cannibalistic?
Although many beetle larvae are not cannibalistic, and can be easily kept together, some of the larvae, especially the bigger ones can hurt the smaller larvae, especially in a limited environment. The "wounded" larva then normally contract the infection and die. In my experience this may often happen to "faster larvae" of some flower beetles or aggressive larvae such as chalcosoma. Goliathus larvae of a similar size would normally not eat each other, but hungry L3 most likely will eat a smallish L1. So if want to keep the larvae in groups, keep them in bigger boxes or keep them separately, especially if you are not sure if they are cannibalistic. Similarly, some adults may hunt the larvae especially if they do not have regular food supplements in their enclosure. I saw a female of mecynorrhina torquata ugandensis hunting their own larvae underground :( which was most likely was caused by protein defficiency in her diet at the time.
How many larvae to start with?
If I have an opportunity I always start with larvae rather than adults. They are significantly cheaper and if I am lucky enough to grow them to adult beetles, the ultimate knowledge for raising the larvae of a species will be obtained. Some of the species could be very hard, or even impossible, as the exact conditions in nature for the larvae are hard to replicate. In any case I tend to start with at least several larvae, and if it is a completely new species I separate them in boxes with different conditions, e.g into boxes with different substrates or keep the boxes at different temperatures.
What is the inactive period for adult beetles?
After a pupa turns into an adult beetle, the beetle stays inactive (sleeps). This dormant period is about 6-10 weeks for big rhino beetles. For some beetles such as megasoma anubis or goliathus orientlais this period could be as long as 6 months or even longer for eupatorus gracilicornis. During this period the beetle finishes its development; therefore it is important that the beetle would not be disturbed and definitely no food is allowed. Disturbed beetles may live shorter lives or even die, especially if food is offered.
More to come