Buffalo Beetles (Eudicella) in Breeding

Introduction

The genus Eudicella includes many popular and easy to rear flower beetles with similar life cycles and captive breeding requirements. They exhibit a wide diversity of colors and even vary considerably within species and subspecies. From a taxonomic aspect, the genus is somewhat difficult. There are some species and many subspecies whose existence is controversial. Various taxonomic sources disagree. In this article, taxonomic structuring is secondary. The scientific names presented here are those commonly used by breeders and resources.

The genus Eudicella belongs to the family Cetonidae. The genus includes over 20 species and at least 50 subspecies. The Y-shaped horn on the male’s head is characteristic of the genus. Male E. euthalia and E. schultzeorum can grow to 50 mm and females can attain 35 mm. However, males of most species only reach a maximum of 40 mm and females about 30 mm. The pronotum is usually green or red. They elytra  are often green with brown, yellow, red or white stripes -or- yellow with black spots. These flower beetles are native to tropical Africa.

The following species or subspecies are presently in culture:

E. woermani
E. gralli alaeri (thiryi)
E. gralli mechowi hubini
E. gralli umbrovittata
E. euthalia
E. smithi bertherandi „Jade-headed Buffalo Beetle“
E. smithi shiratica
E. trilineata interruptefasciata
E. schultzeorum
 

Basic Equipment and Breeding Conditions

Terrarium for egg laying – any covered, glass or transparent cage with good ventilation in which a minimum 15 cm level and 10 liter volume of substrate can be reached. I use glass terrariums of 25 cm lenght, 40 cm width by 35 cm height. The cage is ideal for 5 – 10 adults.  Remember to place several pieces of bark or branches in the terrarium for crawling nad mating beetles and, of course, a dish for feeding.

The most important condition for egg laying is humidity of the substrate. The moisture content of the substrate must be average; not soggy and not dry. Use a moist substrate with    2-3 cm of dry leaves on the surface. Additional moistening is unsuitable and also unnecessary if the substrate is right. Hight humidity in the breeding cage may invite an outbreak of mites or entomophagus fungi.

Boxes for larvae – plastic or glass boxes, with a substrate level of at least 10 cm. The volume of the substrate should be 10 liters or more to prevent drying out of the substrate. Large, deep boxes do not need to be covered but the substrate should be at least 5 cm below the top to prevent escape of grubs. Small or shallow boxes must be covered but require some ventilation. Larvae can be kept separately in small, covered, plastic containers with 0.25-0.5 liter of substrate.

Temperature – room temperature around 23-25°C (73-77 Fahrenheit) is ideal, although fluctuations from 18°C (58 F) to 30°C (86 F) are acceptable.

Lighting regime – terrariums with adults should be placed in a bright place, out of direct sunshine. Light should be provided for at least 12 hours daily. I keep adults in regime of 15 hours of light per day. The light source must be outside the terrarium; intensity of 15-25 watts is sufficient.

Substrate – in general, the genus Eudicella is not choosy about the exact composition of the substrate, more important are adequate volume, quality and humidity. Primarily, I use substrate from materials collected in nature. I collect the components only from known places, where pesticides, fertilizers etc. have not been used.

Basic components:
- decomposing leaves of beech and oak are the best; maple, birch, lime, poplar, apple  trees and many others are also suitable
- rotten wood from the same type of trees

Potential components:
- old cow dung
- compost

Old, decayed leaves are the most important part of the substrate for breeding  Eudicella. The leaves must be partly decomposed, from places where several years‘ level is found. Pieces of wood, sticks and woody soil found in the leaves are not a problem. The ideal time to collect leaves starts several days after heavy rains, when the humidity of the leaves is suitable and additional watering is not needed. Leaves shoul be broken into small pieces by a garden crusher or grinder. Crushed leaves can be stored in plastic bags in a dark, cool place. Old leaves comprise 50%  to 100% of the substrate for breeding Eudicella.

Well-rotted wood from trees of the same species can be used. The wood must be crushed into small pieces. Rotten wood is an alternative substrate and can be used as 100% of the substrate. Depends on local conditions and what is easiest for the breeder.

Not everyone is willing to use dung, nor can everyone easily collect it. Larvae feed and grow well on old cow manure. Finding good material is a little difficult. The dung has to be several months old and collected in pasture areas where no pesticides and no veterinary medications have been used in cattle breeding. Material can be collected from a good area and stored on plastic bags for over a year. dry cow dung can be stored for several years. The aged cow dung can be used as a supplement for feeding larvae – up to 30% of the substrate. Small, slightly wet pieces of dung can be buried in the bottom of the substrate.

Composted grass and garden wastes (without much soil) is also a good supplement for feeding larvae. Compost can be used instead of cow dung, likewise about 30% volume of substrate.

For egg laying  I recommend a substrate of 100% crushed leaves and for larvae a mixture of 60% leaves,  30% old dung and 10% rotten wood.

Feeding adults – slices of banana, watermelon, sugar melon, and most fruit are acceptable. Eudicella prefer bananas. I recommend placing banana slices on a small dish, spray lightly with water and add several drops of real maple syrup or honey. g every other day is sufficient. The importance of feeding adults protein is a question. Sometimes, Eudicella adults, especially females,  feed on small larvae. This may be due to a desire for protein. Some breeders sprinkle fish food flakes on the banana or offer soft pieces of dog or cat food. The additional protein might slightly increase adult longevity and egg production.  

Life Cycle

After mating, the females begin to lay eggs in the lower level of the substrate. Usually they deposit from 20 to 50 eggs. I have had a maximum of 90 from a single female. In 2-3 weeks, small, white larvae hatch (first instar or L1). A few aggs may not hatch several weeks or months. 

Following about 2 weeks of feeding the larvae molt into second instar (L2) and after 1 - 2 months into third instar (L3). L3 are very glouttonous. After 5 - 6 months of feeding the white larvae change to a creamy yellow and then construct oval cocoons from the substrate. 2 - 3 months after pupal cell formation they become adults. During this time the larvae change into prepupae, then pupae and finally adults. Young adults are soft and vulnerable at first. Once the exoskeleton hardens, they leave the cocoons. The newly emerged adults are very active and feed and mate for hours. As adults Eudicella live 2 - 3 months, occasionally 5 months or more. Their activity and reproductive ability rapidly declines with age. Total time taken from egg to adult is 7 - 10 months.

Recommendation for Breeding

Choose a good pair or group of beetles. More females are better. Provide one male for 2 - 3 females. Surplus males fight each other and disturb females during feeding and egg laying. Place no more 10 adults in a 30 - 40 l terrarium with 10 - 15 liters of substrate. Beetles used for breeding should look healthy, have typical colors and be good sized. The males should have well-developed horns. Don't  breed adults with heavy deformities, like protruding wings, scission of elytra, males with misshapen or cutaway horns, individuals with salient genitals or extremely tiny adults. Don't worry about minor deformities of the elytra, which were probably caused during ecdysis in the cocoon.

If mating and feeding proceed successfuly, check the substrate after 4 - 6 weeks. When searching for grubs, first scoop the dry upper level into a container. Place the moist lower lewel with the eggs in a different container. Larvae can be found in both levels of the substrate. Check carefully and remove all grubs. Then, put back the lower level and add some new substrate. Next, put the dry substrate on top and return the terrarium to its original shape. Repeat this procedure every 2 - 4 weeks. It is necessary to remove grubs because older larvae can kill eggs and small, newly hatched larvae. Keep the substrate 2 - 3 months after the parents die because larvae from late developing eggs may still be found.

Place the grubs in bexes with fresh substrate. Eudicella larvae are usually kept together. To reduce cannibalism and ensure enough food, place no more then 50 L1-2 or 30 L3 into 10 liters of substrate. Due to the high concentration in the rearing box, a few will get eaten or be disturbed during pupal cell construction. If there are only a small number of grubs or it is a new, rare species, keep the grubs separately to prevent cannibalism.

It is important to maintain the quantity and quality of substrate when raising larvae. When the frass (excrement) makes up 50 % or more of the substrate, place larvae in new boxes with fresh substrate. Substrate should be changed about three times before maturity. This means one larva consumes approximately 1 liter of substrate. When ful-grown grubs begin to turn yellow, use slightly drier substrate, particularly drier on the surface .          

Larvae usually construct cocoons in the middle of the substrate. Some species form cocoons on the side or bottom of the cage. Do not interrupt cocoon construction. If the larvae are disturbed, they abandon incomplete cocoons and cannot make a new one and finish their development.           Although is best not to disturb cocoons, it is possible to remove older, hardened cocoons from the breeding box. Place them in damp substrate to prevent desiccation. If cocoons dry up the adults may be deformed. Newly emerged individuals can be placed in the breeding terrarium.

Problems in Breeding

I believe the main problem in breeding Eudicella and many other genera is  a complex of negative phenomenon, observable as degenerative changes. These changes are encountered primarily in long-term, captive-bred, closed populations. The cause may be inbreeding over multiple generations along with the very different captive conditions versus natural conditions. The most common problem is deformities of the exoskeleton as mentioned previously. Other problems include an inability to transform to adult, decreased size of adults, decreased collection of eggs, decreased fertility and extinction of the population.

Solution to these problems are:
- exchange of breeding material between separated populations
- use of only healthy, flawless individuals for breeding
- import of wild individuals to augment the gene pool

Other troubles, like mites, nematodes and entomophagus fungi are not common as long as the principles from the previous text are adhered to.

Hybridization

Species and subspecies in this genus willingly hybridize. Hybrids usually exceed their parents in size, are chracterized by elevated fertility and highly variable coloration. This partly explains why the classification of Eudicella is so difficult. Hybrid individuls often resemble some described species and subspecies. Some wild-cought specimens may be uncommon, natural hybrids. Part of breeders are against hybridization and prefer breeding pure species and subspecies. I think controlled hybridization is acceptable for breeders who want to obtain interesting material for dead specimens. It is important to label dead hybrid specimens for taxonomic purposes and even more important to mark live hybrid specimens.

Interspecific hybrids between Eudicella woermani and Eudicella gralli ssp., Eudicella smithi ssp. and Eudicella gralli ssp. are well known.

Source:
Oldrich Jahn: (September 2002) Buffalo Beetles in Breeding, Invertebrates-Magazine, Vol. 1, Issue 4, publishing Elytra and Antenna, OH, USA          

Notice:

this way of breeding could be successfuly used for almost all others flower beetles, like genus Chelorrhina, Mecynorrhina, Dicronorrhina, Smaragdesthes, Neptunides, Genyodonta, Ranzania etc. 

(2.55cm = 1 inch. 1 liter = roughly a ¼ gallon)