Kenya has a headache trying to deal with 'devil cactus'

The ability to take root from every part and layer of thorns makes Opuntia cacti a threat to people, cattle and wildlife.

The hungry elephant wanders on the grasslands of Laikipia county and finds its favorite snack, the sweet fruit of an invasive cactus. The endangered mammal stopped and ate the fruit, but also swallowed the thorns. The thorns attach themselves to its mouth, intestinal wall and stomach. Not only does the pain cause abscesses for the animal, the spread of cacti also attracts many elephants near the human residence, promoting conflict between humans and elephants.

Picture 1 of Kenya has a headache trying to deal with 'devil cactus'
Opuntia cacti grow rampant.(Photo: CNN).

Opuntia, also known as prickly pear cactus, was brought to Kenya in the 1940s by British colonists to make a living fence, but this tree has grown out of control in recent years, threatening elephants and many animals. Another wild, spread through farms and plantations. According to the International Center for Agriculture and Biology (CABI), Opuntia with the nickname "devil cactus" has grown rampant over 500km 2 .

Authorities and locals have been fighting for control of Opuntia cacti for several years, using machetes, excavators or insects that eat cacti, but without success. Currently, they are adopting new technologies such as bio digestion, drones and mobile applications to control cactus.

CABI estimates that if left unchecked, invasive cacti will cover 70% of Kenya's natural pastures. Opuntia cacti are especially hard to control. If you cut or uproot, even the smallest parts of the tree can take root and regrow. The thorny layer also makes extermination of this invasive tree extremely difficult, said Arne Witt, CABI's regional coordinator."If you remove a tree and drop flowers or fruit, it will start to grow back," Witt said.

Opuntia cacti spread further thanks to birds and animals like elephants or baboons. These species often eat fruits and disperse seeds. If grown thickly, the cactus can prevent people from having access to the house and the cattle cannot access food. A 2017 study by Witt found that Opuntia cacti caused great economic losses for nearly half of the surveyed households across the country, due to the loss of natural grass resources and poor health.

According to Witt, controlling by birth means is the best way to kill Opuntia cacti, including the release of aphids eating cactus. In the early 1900s, an area of ​​more than 40,000 square kilometers in Australia was affected by Opuntia cacti before authorities used aphids for control.

Another way is to use this plant to produce biogas. Tom Silvester, CEO of Loisaba Conservancy, said the wildlife conservation organization uses 600 kilograms of Opuntia cacti a day to create gas for use in the kitchen of the anti-poaching patrol team, helping serve 20-30 people. Loisaba suggested that bio-digestion may be a temporary solution to dealing with Opuntia before releasing aphids.

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