The Goliathus calf is considered by many to be the Holy Grail beetle breeding. Its massive size and colorful pattern make it a highly sought after item in the minds of many collectors. Specimens over 10 cm are calculated to the last millimeter and in hundreds of dollars. However, it is their biology that has fascinated me the most. A veil of mystery surrounded his parenting habits. People were already attempting their breeding cycle in the 1980s with little success despite the price of each larva being over $100. Breeders theorized that perhaps Goliathus larvae required a special tree essence not found outside of Africa. Meanwhile, the hobby of raising beetles continued to gain popularity in Japan and elsewhere. Newer techniques for breeding them were discovered, such as using fungal mycelium in a wood mixture called kinshi to reproduce Lucanidae specimens larger than those found in the wild. One day, a well-known American breeder, Orin McMonigle, discovered that by feeding his rhinoceros beetle larvae dog food, he could accelerate growth and succeed at a higher rate than larvae fed only substrate. The use of protein additives was perhaps similar to the invention of the wheel in the world of beetle farming. Suddenly, breeders tested the pet food with different species (Lucanidae, Dynastidae and Cetoniidae) that were in the breeding and found that most of the species accepted the dry pellet successfully. A Japanese breeder admitted that without the discovery of this technique, Goliathus breeding would not have been possible.
My experience with Goliathus species began in 2004. I had ordered a dozen Goliathus goliatus and Goliathus orientalis larvae from a Czech dealer. I knew I was facing an uphill challenge. All he had were a few reports of European breeders who had failed or had mediocre results in their breeding attempts. Against all odds, I was able to breed both species in imago forms. I had a 25% mortality rate as a larva and maybe another 25% as a pupa. In total, I was only able to breed 3 females in total: two Goliathus goliatus and one Goliathus orientalis, the rest being males. I failed to breed the latter species even though the breeding conditions were both identical. After a full second generation, my determination to succeed and with the combined experience and knowledge of fellow Goliathus breeders have made my experience a success. While I don’t consider this care sheet to be the final bible on Goliathus breeding, it is one that I have had success with. Goliathus beetles are found in Equatorial Africa (Cameroon, Congo, Ivory Coast, and Ghana), where the rainforest is densest. The only exception concerns the smaller species, Goliathus albosignatus, which can be found in the more temperate part of southeastern Africa (South Africa, Tanzania). The largest males can measure up to 11 cm and have a distinctive Y-shaped horn. The male larva is capable of weighing more than 100 g. while the female can weigh between 40 and 60 g.
It is difficult to tell if the Goliathus is a “white” beetle with “dark” patterns or vice versa, as some species can be found in different varieties with very different elytra patterns. For example, Goliathus goliatus can be found in these different forms: goliatus (yes, that would be Goliathus goliatus goliatus), apicalis, conspersus, undulus, albatus, and quadrimaculatus. The two extreme forms are: Goliathus goliatus goliatus with a set of entirely dark elytra with a short white band near the pronotum and Goliathus goliatus quadrimaculatus as an entirely white beetle with four distinct dark spots on the four corners of its elytra. The other forms would fall on the spectrum between these two color patterns. Although Goliathus is part of the Flower Beetles – Cetoniidae family (I have a hard time visualizing these gigantic beetles flying from flower to flower) that’s where the similarity ends in terms of their breeding requirements. The specific diet of the larvae and their delicate pupation phase are the reasons why Goliathus is considered a difficult species to breed and is not recommended for beginners. Imagos (adults) are extremely active and the male can often be seen chasing females in the breeding tank. A 12 hour light source is recommended as they are diurnal. One note worth mentioning is that the male Goliathus is extremely territorial. Two males sharing a tank will constantly push each other for dominance. This behavior will take time away from their normal breeding activities with the females. Adults can be maintained (temperature, feeding, misting, and lighting conditions) in the same manner as other Cetoniidae beetles.