Climate Change Fuels Libya’s Red Spider Mite Scourge

Tiny but destructive red mites which thrive in arid conditions have led to huge crop losses in northwestern Libya and threaten to wreak havoc across the wider region.

The red spider mites, typically measuring less than half a millimetre, feed on a wide range of plants, sucking the sap and causing leaves and fruits to dry up and fall off.

Farmers at the Wadi Al-Hai agricultural development project in Libya say an infestation of the mites this year has completely destroyed many of their fruit and vegetable trees.

“The pest was not a big problem in the past … but it has worsened in recent years and has become unprecedentedly brutal, due to climate changes that have clearly affected Libya,” explained Fathi Al-Tahir, a plant protection specialist at the Ministry of Agriculture and Animal Resources in Libya’s Government of National Unity.

The vast Wadi Al-Hai projectin the Jafara Plain region covers an area of ​​12,000 hectares and includes more than 400 farms. It is mainly planted with fruit trees such as figs, pomegranates and grapes, as well as vegetables and other crops, according to Ali Ibrahim, the project manager.

Ashour Suwaisi, coordinator of the agriculture and livestock sector in Garyan municipality, toldSciDev.Netthat most of the trees in his area were infected, and the pest later spread to other cities.

Rapid reproduction

Red spider mites, also known as two-spotted mites, can reproduce rapidly in high temperatures and adapt to various environmental conditions, making them one ofthemost destructiveagricultural pests in North Africa.

They have spread across several other countries, including Morocco, Algeria, Tunisia, and Egypt, since first entering North Africa during the 1950s and 1960s, via seedlings imported from Europe and Asia.

Jamal Breim, who owns one of the affected farms in Libya, toldSciDev.Net: “The pest first appeared on my farm in 2017, infecting 1,400 fig trees and 1,200 pomegranate trees at an unprecedented speed.

“Since then, production has become difficult. The pest has destroyed all the fig, pomegranate, and palm trees and has also spread to the olive trees.”

He says his efforts to combat the mites using pesticides have been unsuccessful due to the poor quality of pesticides available.

Breim blames the government and international organisations in the sector, which he says have ignored the plight of farmers affected by the worsening problem.

Optimal climate

According to Suwaisi, climate conditions have accelerated the spread of the pest, especially in the last two years.

“The red spider mite thrives in drought,” he explained, adding: “The rainfall rate in Wadi Al-Hai has decreased from 270 mm annually to 50 mm in recent years, in addition to high temperatures and dust storms.”

The rise in temperatures accelerates the life cycle of the red spider mite, as it reduces the time it takes for the insect to move from egg to adulthood, increasing the rate of reproduction.

“In recent years, we have witnessed unusually high temperatures in the spring and autumn, which has increased the spread of [this] and many other agricultural pests,” said Al-Tahir.

Pesticide resistance

Al-Tahir warns against using non-specific pesticides to combat the mites, stressing that this can contribute to pesticide resistance.

“Many North African countries rely primarily on acaricides to manage pests in fruit and vegetable trees, but there are reports of significant resistance to these pesticides,” said Rachid Boulmatat, research assistant in agricultural entomology at the International Center for Agricultural Research in the Dry Areas (ICARDA).

He said the red spider mite had become a major pest affecting fruit trees, vegetables, and ornamental plants across North Africa.

“ICARDA proposes strengthening quarantine systems and farmer training policies, as well as adopting integrated control strategies and establishing systems for early detection of the pest,” said Boulmatat.

Mohamed Amrani, chargé d’Affaires of the UN Food and Agriculture Organization in Tunisia, also said pesticides could be problematic.

“The only solution is monitoring, inspection and having a laboratory to determine the pesticide’s components and validity,” he toldSciDev.Net.

The losses caused by red spider mites are undoubtedly huge, according to Abdul Majeed Al-Baghdadi, head of the management committee of Libya’s National Center for Prevention and Agricultural Quarantine, Tripoli branch.

He said the pest had spread throughout the country from the eastern and central regions to the entire western coast from Zliten to Zuwara, as well as the Nafusa Mountains, the oases and the cities in the South.

“The centre intends to launch a campaign to combat the scourge if the necessary budgets are available and the security conditions are stable,” Al-Baghdadi added.

This piece was produced by SciDev.Net’s Middle East and North Africa desk.