An abnormally large number of desert locusts are expected to hatch beginning in January in Yemen, threatening to eat through a chunk of an already dangerously depleted food supply. Most Yemenis rely on humanitarian aid for food and water following a year of civil war and the rise of jihadist violence in the Middle East’s poorest nation.

Experts from the United Nations Food and Agriculture Organization (FAO) are estimating that an abnormally active cyclone season and the El Niño phenomenon will make Yemen a more fertile ground for locust eggs. Locusts do not attack people or carry major diseases, but they require a large amount of food to stay alive and can rapidly eat through entire crop fields.

“Extreme weather events, including torrential downpours, have the potential to trigger a massive surge in locust numbers. Rain provides moist soil for the insects to lay their eggs, which in turn need to absorb water, while rains also allow vegetation to grow which locusts need for food and shelter,” explained FAO senior locust forecasting officer Keith Cressman this week. “The effects of a locust plague can be devastating on crops and pastures, and thus threaten food security and rural livelihoods,” he added.

Al Arabiya notes that the worst of the locust hatching is set to begin in January, but an FAO representative in Yemen says hatchings have already begun.

Weather and agricultural tracking experts have been warning for at least a month of the possibility that locusts could deliver the final blow to a tenuous humanitarian situation in Yemen. In November, the FAO warned that they had begun to see indications that the winter would yield “favorable ecological conditions” for the insects. The Weather Channel noted then that Yemen was importing up to 75 percent of their food in 2010, long before Shia Houthi rebels stormed the nation’s capital, Sanaa, in January 2015, and pushed the country into civil war.

It is not known how much food Yemen imports currently, but what the United Nations has estimated is the number of Yemenis unable to feed themselves do to military violence and lack of basic resources: 21 million as of June 2015, or a full 80 percent of the population of Yemen. 20 million of these are believed to be lacking potable water, which can result in the rapid spread of diseases through the use of unclean water. A major outbreak of Dengue fever struck Yemen in June, with estimates of the number of afflicted reaching 8,000. With the changing of seasons, Dengue becomes less of a threat than famine, however.

The political situation in Yemen has deteriorated in the past few months due to jihadist groups taking advantage of the power vacuum created by the struggle between President Abd Rabbuh Mansur Hadi and the Houthi insurgency. Prominent among these groups has been the Islamic State, which orchestrated its most devastating attack on Shiite targets in Yemen on Sunday, killing the governor of southern Aden province, where presidential loyalists have retreated.

Al Qaeda has also established a significant presence in Yemen; Al Qaeda in the Arabian Peninsula (AQAP) is believed to be the most formidable of Al Qaeda’s branches. The group has been strengthened by the return of Ibrahim Al Qosi, who recently appeared in an Al Qaeda propaganda film after being released from the detention facility at Guantánamo Bay.

Pressured by the growth of these groups, which benefit neither side of the Yemeni power dispute, both groups will sit down for peace talks on December 15 in Switzerland, and are expected to observe a ceasefire while talks are ongoing. The groups had agreed to a peace process in April, which had not yet begun. “I have been strongly encouraging the parties to work on confidence-building measures including implementing a ceasefire, the releasing of prisoners and facilitating the delivery of humanitarian supplies,” UN Special Envoy to Yemen Ould Cheikh Ahmed said following the announcement of these talks.