Luca Luiselli, The Rivers State University of Science and TechnologyOne of Africa’s giant beetles is just one step away from extinction. New research has found that one species of the enormous Goliath beetles has been almost wiped out by the west African cocoa industry and, to a lesser extent, by the international trade in dried insects. Luca Luiselli, a professor of biostatistics and ecology at the University of Lomé (Togo), has researched threatened species in African forests for 30 years. He explains what has gone wrong and how the Goliath beetle could be saved.What is the Goliath beetle and why is it so important?The Goliath beetles (genus Goliathus) are among the world’s biggest insects. There are five different species. They grow up to 110mm long; males have Y-shaped horns and females do not have horns. The beetles are found in the rainforests of Sierra Leone, Liberia, Guinea, Côte d’Ivoire, Ghana, Burkina Faso, Benin, Nigeria, Cameroon, the Democratic Republic of Congo, Uganda and South Sudan.Beetle larvae, or grubs, are omnivorous and likely scavenge on meat as well as debris of plants. This means they have an important role in moving nutrients throughout the forest ecosystem to nourish other plants and animals. The adult beetles feed only on the sap of a few tree species in mature rainforest areas.The Goliath beetle is an excellent indicator of forest health: if they are abundant in a forest, it means the forest is in a good enough condition to support other species. But when their populations decline, this is an early warning indicator of emptying forests and eroding ecosystems.How did you study this beetle?I was studying reptiles under threat in west Africa’s forests with a team of ecologists from African and European countries. I realised that the Goliath beetles shared the same habitat and could also be endangered.My team then began intensive face-to-face interview campaigns in communities to find out if local people had noticed fewer Goliath beetles about. These local people included hunters, farmers, snail and mushroom gatherers, and collectors of timber and other forest material. When they confirmed our fears, we decided to launch an in-depth research project. This shows that traditional ecological knowledge is very valuable in driving research decisions.To start, we tracked the trees that were oozing sap because the adult (imagoes) beetles are known to feed on sap during the daytime. We then noticed which treetops they flew through every morning. We returned at night to collect and measure them before releasing them back into their natural habitat.What did your research find?We discovered that two of these giant insects, Goliathus regius Klug and Goliathus cacicus Olivier, are threatened with extinction.Goliathus cacicus is the smaller of the two giant beetle species; it’s up to 95mm long (normally 60-84mm) and lives only in mature rainforests. Goliathus regius can grow up to 105mm long (normally 75-95mm) and prefers to live in drier forests. Occasionally, they live in the same patch of forest and even on a same tree and mate, giving birth to natural hybrids.We estimate that about 80% of the Goliathus cacicus population has been wiped out in Côte d’Ivoire if we consider the amount of forest destroyed for cocoa farming. Goliathus regius has similarly lost about 40% of its natural habitat. Based on the recorded habitat loss, we believe Goliathus cacicus has had a catastrophic decline over the past 30 years.We also found that Goliathus cacicus seemed to have gone extinct in several areas of west Africa, like the Banco Forest National Park in Abidjan, Côte d’Ivoire. This is likely because thousands of these beetles have been captured and sold on the international dried insect market. (We estimate this based on the calculations of expert collectors that have monitored the insect trade for decades. Nowadays, most of this trade happens online on eBay, Facebook and other platforms.)Other closely related species, such as Goliathus goliatus, are still sold in their hundreds on the dried insect market, primarily in south-western Cameroon and, to a lesser extent, in Kenya and Uganda. Our observations of the online trade show that they are exported from there to western markets.Because there are so many living across a very wide area, they are not yet an endangered species, although nearly so. There are huge parts of Africa where beetles are protected. Forests in Nigeria, Cameroon, Uganda, South Sudan, Rwanda and Kenya offer valuable shelter to Goliathus goliatus. Gabon, the northern Republic of Congo and northern Democratic Republic of Congo have vast and largely pristine, inaccessible forests where Goliathus goliatus beetles are not under threat.How can these beetles be saved?It is imperative to protect their natural habitat – the remains of the forests in Côte d’Ivoire and Liberia where they’ve lived. Particular attention should be focused on protecting the trees where these beetles tend to concentrate. We recommend that community elders should be consulted and involved in order to identify the target trees and carefully protect them.Even those species that are not in danger right now need humid forests if they are going to survive. But they’re facing increasing threats due to deforestation, land conversion, mining and climate change. They may be the next to be threatened and should be carefully monitored. Apart from protected reserves and national parks (the most important being the Taï National Park in Côte d’Ivoire), there are no real measures to limit the expansion of the cocoa plantations in west Africa.We also recommend awareness campaigns in local communities to encourage people to protect these beetles. For example, it would be very important to create “certified forests” where the local communities could harvest and sell a limited number of beetles to earn a livelihood, while also helping to conserve the forest and generating income from Goliath beetle ecotourism.We also recommend that people should not try to save the beetle by collecting them and breeding them at home, or in breeding facilities. There is no scientific support for ex situ captive breeding to be of any utility for the survival of Goliath beetles.An important step would be for scientists, government agencies and non-profit organisations in west Africa to agree on an action plan to conserve the Goliath beetles, and especially Goliathus cacicus. This will help the countries coordinate conservation planning for these species.Luca Luiselli, Professor of Ecology, The Rivers State University of Science and TechnologyThis article is republished from The Conversation under a Creative Commons license. Read the original article.