Baobabs aren’t presupposed to fall. They will stay for as much as 2,500 years. Well-known for his or her resilience, these large timber have stood tall throughout Africa, weathering droughts and winds that flatten every thing else.
A small inhabitants of 102 baobabs can also be present in Oman on the south-eastern tip of the Arabian Peninsula, the place baobabs had been launched over 1,500 years in the past by merchants from Africa.
Nonetheless, a number of baobabs have just lately collapsed and died in Oman, not from illness, drought or outdated age, however from infestation by a beetle that has abruptly confirmed lethal to baobab timber – the mango stem-borer (Batocera rufomaculata).
I am a baobab ecologist who labored with two environmental scientists from Oman, Ali Salem Musallm Akaak and Mohammed Mubarak Suhail Akaak, to analyze what number of timber had been contaminated by the beetle, how the infestation had affected the timber and what number of had died consequently.
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We surveyed 91 baobab timber in Oman and located that six had been killed by the beetle. An extra 12 baobab timber had been infested by the beetle’s larvae.
That is the first time that an insect has been discovered to kill grownup baobab timber. The identical beetle is understood to break and kill different species of timber.
Our findings have essential implications for the conservation and administration of baobabs all through Africa. The mango-borer beetle has not been present in mainland Africa but however it could change into a brand new menace to baobabs if it disperses.
Our findings permit for early detection in addition to analysis into efficient methods to manage the beetle earlier than it spreads to Africa.
If the mango stem-borer had been to succeed in mainland Africa, the place the baobab is taken into account a keystone species, it may devastate each ecosystems and livelihoods. Baobabs have over 300 makes use of for folks, together with fibre comprised of the bark, meals from the leaves and the fruit, which is harvested for its nutritious pulp and offered in native and international markets.
Meet the killer
The mango stem-borer is native to south-east Asia. Adults stay for less than two to a few months, feeding on shoots and bark. Throughout that point females can lay as much as 200 eggs, reducing small slits in tree bark and sealing every egg inside.
The grubs or larvae spend nearly a yr hidden inside the wooden, tunnelling by the residing tissue that carries water and vitamins. As they feed, they weaken the tree and finally kill it.
This beetle has lengthy been one among Asia’s most damaging fruit-tree pests. It assaults mango, jackfruit, mulberry and fig timber, usually killing mature hosts. It unfold to the Center East, the place it was first recorded in 1950 and has broken fig plantations.
In 2021, an grownup baobab in Wadi Hinna, a semi-arid valley in Oman’s Dhofar Mountains, collapsed and died. When researchers examined the fallen trunk, they found it was infested by mango stem-borer larvae.
By 2025, seven baobabs had died, and lots of extra had been contaminated, confirming {that a} seemingly innocuous fruit-tree pest had discovered a brand new host.
Learn extra: Madagascar’s historic baobab forests are being restored by communities – with just a little assist from AI
The very qualities that make baobabs extraordinary survivors in dry climates additionally make them perfect nurseries for borer beetle larvae. Their saved water, delicate trunks and nutrient wealthy tissue feed and defend larvae for almost a yr till they mature.
Because the larvae feed, they hole out the inside of the baobab, leaving the outer bark intact and the infestation hidden, till the stem abruptly collapses.
Battling the beetle
When the primary deaths had been recorded, Oman’s Setting Authority launched an emergency management programme with assist from native communities and researchers.
Infested timber had been handled with systemic pesticides, larvae had been manually faraway from trunks, and lightweight traps had been set to draw and kill grownup beetles at evening. Tree stems had been additionally coated with agricultural lime and fungicide to discourage additional egg-laying.
These actions appear to have slowed the outbreak, however they’re labour-intensive and possible just for a small space. Throughout a continent, such strategies can be unattainable to keep up.
Learn extra: The key lifetime of baobabs: how bats and moths preserve Africa’s large timber alive
In Asia, scientists have recognized pure enemies of the mango stem-borer, together with parasitic mites and nematodes. These may very well be used as the bottom of a long-term organic management technique.
My analysis argues that utilizing organic management to cease the beetle reproducing should be developed as a precedence earlier than infestations cross into Africa.
Stopping a variety to Africa
Grownup beetles can fly as much as 14 kilometres in a single evening, and international commerce makes it straightforward for bugs to cross borders unnoticed, hidden in crops and ornamentals destined for the agriculture and backyard sector.
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The beetle already happens on islands comparable to Madagascar, Réunion and Mauritius. Baobab researchers have no idea if the mango stem-borer has attacked the native baobab populations of Madagascar, the place the timber are an indigenous plant.
Early detection and prevention are far cheaper, and much simpler, than attempting to cease an outbreak as soon as it begins. Stronger biosecurity inspections and different measures are wanted at African ports and borders to cease the beetle crossing borders, significantly in shipments of wooden and stay crops.
Collaboration between analysis establishments, agricultural departments and the baobab trade may even assist: sharing knowledge, testing organic controls and establishing monitoring methods earlier than additional outbreaks happen.
A warning – and a possibility
The dying of baobabs in Oman is greater than a localised drawback. It is a warning of what may occur elsewhere if the beetle spreads unchecked.
However it additionally gives an opportunity to arrange. If African international locations act now, tightening biosecurity, supporting analysis and elevating consciousness, they will defend one of many continent’s most iconic and life-sustaining timber earlier than this menace ever reaches African shores.
Sarah Venter, Baobab Ecologist, College of the Witwatersrand