Introduction The group of Beetles (Coleoptera) we deal with here are from the Scarabaedae (Scarabs & Chafers) Dynastinae and Lucanidae (Stags & Rhino Beetles) The Scarabaedae family, which contains over 20,000 species world-wide, includes some of the largest and most spectacular of the beetles and some of the most colourful. For the purposes of these notes we refer to the group as fruit beetles and hope that some of our accrued knowledge from the last years of breeding will be of use to all fellow enthusiasts. Substrate The materials used to rear beetles of the subfamilies cetoniinae, Lucanidae and Dynastinae (loosely referred to as ‘The fruit beetles’) are decomposed deciduous hardwoods and leaf litter that has aged to the point that it has become soft, this is mixed to create the rearing substrate which is the very foundation of captive scarab breeding. The first thing you need to do is locate some sources of decayed wood and leaves. If you have access to some deciduous woodland that will certainly be one of the best places to look for what you need. The best varieties of wood and leaves to use are those from species of Oak trees (Quercus sp.) and Beech (Fagus sp.) both are suitable. . It is possible to use freshly fallen leaves once they have been on the ground for a few months, but if you can get leaves that have been “composting” for a couple of years and have obvious signs of decay, that will be even better! For the wood, what you’ll be looking for rotten, decomposing logs and stumps of deciduous hardwood trees, we require it to be breaking down into a suitable, crumbling consistency, we liken it to cooked chicken, with a nice yellow/beige colour and moist to the touch. The soft wood is mixed into the leaf litter at a ratio of between 10% wood 90% leaf litter to 50:50 depending on the species of beetles being kept.. . Cages Now that you have your substrate created, the time has come to obtain some containers suitable for keeping the species of fruit beetle you wish to breed. There are many shapes and sizes of plastic boxes available that are quite suitable for the breeding and rearing of fruit beetles. Most such boxes are manufactured for the storage of clothing, blankets, and all sorts of other household items. Many are made of transparent plastic, and have lids that lock down nicely and tightly - both ideal features for an insect-rearing container. Larger storage boxes can be used for rearing the smaller grubs in groups, while smaller boxes can be used for the rearing of single, large larvae. The lids of such boxes will need some slight modifications made to them to allow for proper ventilation, when you first start out, as you will need to acquire a “feel” for just the right moisture content of your substrate at the start, but for now just cut out some small holes in the lid of your container to allow for ventilation. One of the most suitable of the ready built plastic tanks is marketed as ‘Beastie-boxes’ these are solid sided with a clear sliding lid, the big advantage here is that it comes unvented and made from an expanded plastic material that is easy to work without the risk of splitting whilst being drilled. Setting up a Cage Now we have the cage add the substrate with a min. depth of 15cm this depth is suitable for most of the smaller species, if however you wish to start with the larger species we would suggest a depth of 30cm as these lay fewer eggs and are unwilling to lay if they can’t get deep enough. As a rule of thumb, the amount of space available between the substrate surface and the cage’s lid should be about equal to the depth of the substrate, this gives the beetles room to fly which they do very well even in restricted space. We also like to add flat bark over the substrate to prevent rapid evaporation of the substrate and some sticks for climbing. Having a fluorescent tube light for your breeding cage can be helpful in encouraging breeding in the day active species, and although not essential it shows off these wonderful beasts colours. Beetles We like to start with around 5 pairs of the beetle species we intend to breed in order to get a good supply of eggs from them. Most male cetoniinae are safe to keep together in the same cage, but some of the dynastinae, especially Chalcasoma spp. will fight if kept together and although they do some damage to each other, the biggest problem is that the looser cannot leave the victor, so fights can last hours and waste the males time and strength. When you find a new species that are keen to battle and you have restricted space simply start up a new colony or remove all but one of the males and swap the males over periodically to ensure that you have a maximum gene pool. Temperature Most tropical scarab species do best at a temperature of between 25-30°C 75-90° F. For species from cooler parts of the world such as Europe and North America, the temperature can be allowed to drop below 20°C, and in fact some species that come from cooler climates need a seasonal variation in temperature to properly complete their life cycle. Feeding Most Fruit beetles will accept soft fruits such as banana & guava in captivity. A few species like apple, pear or even cabbage, so give them a mixture of fresh fruit every second day and watch for their preferences. Slight misting of the cage and beetles will supply moisture needs for both the insects and the substrate. Just mist the cage if the environment starts to look a bit dry, but be careful that it is not just the top layer that has dried and the lower levels are still saturated! When in doubt gently dig down along the side of the cage and check the lower levels. Breeding Pairing happens soon after emergence with males actively hunting out fresh females, in fact they are so keen on pairing that if you have a lot of males hatch with only a few females available it is best to temporally remove some of the males to make sure that the females are successfully mated. The female beetles burrow into the substrate to lay eggs, or may deposit them near the surface; this depends on the size of the species. Most of the larger types, lay (oviposit) the eggs near the bottom of the substrate. Once eggs have been laid it is vital than the substrate is prevented from drying out. We find that the eggs are laid two to four weeks after the Beetles have mated and unless the substrate requires attention, the container is left alone for at least 6-8 weeks. We do this as apart from the fact that the eggs are small and easily missed, they are also delicate and can not only be damaged in handling but also by putting back at the wrong depth to which they where laid. Growth Fruit beetles follow a complete metamorphic cycle with the Grubs or Larvae having three stages of development, known as instars, regarded as L1, L2 and L3 with a moult separating each phase. After each moult the grub has a larger head to body size ratio and during this phase the body grows until it takes on a very full look, then it moults out to the next instar and once again takes on the larger head to body look. The complete cycle of the grubs varies according to the species in question, but as a rule of thumb, the larger the slower. With most of the species of the small to medium types taking around 12 months and the larger species up to 3-5 years. When your grubs reach the maximum growth point in the late L3 phase, they will slow down eating, and begin construction of their pods (Pupae cells). The pods of the larva are basically the same as the cocoon of a moth, but made of bits of wood and leaves stuck together with glue produced by a special gland in the larva. Once all of the larvae have made their pods, no further substrate changes or food additions will be necessary, just make sure that the substrate does not dry out. Pupation time varies depending upon species. Many of the small to medium fruit beetles can do it in 4-6 weeks, but most beetles take at a few months. In many cases, the larger the species you are breeding, the longer you can expect larval durations to be, and the longer you’ll have to wait for pupation to be completed. Your beetles will not all be emerging from their pods at the same time, just as not all of them pupated at the same time either. Instead, you will have a period of time in which they will be emerging gradually, until eventually, all have come out from their underground pods and this is something that you will never get bored with, each example a living jewel.