Infectious insect tears through Israel, putting the citrus industry at risk

The Asian citrus psyllid, an insect that spreads a bacterium that is fatal to citrus, recently escaped the area in which the Ministry of Agriculture contained it to

An abundance of ripe fruit hangs from trees in an orchard (photo credit: Yehoshua Halevi)
An abundance of ripe fruit hangs from trees in an orchard
(photo credit: Yehoshua Halevi)

The Asian citrus psyllid, the insect vector of bacterium that spreads Huanglongbing disease (HLB), the most destructive citrus greening disease, has begun to spread in Israel, putting the country’s flourishing citrus industry at further risk.

The invasive species was initially identified in the Hefer Valley area near Netanya by the Plant Protection Services Laboratories of the Ministry of Agriculture in July 2021. The traceable lesion spanned 750 dunams of citrus groves in the area.

The source of the outbreak’s initial penetration into the country is still unknown. The Ministry of Agriculture hypothesizes that the likely culprit was unregulated citrus that was smuggled into the country.

Candied citrus peels (credit: PASCALE PEREZ-RUBIN)Candied citrus peels (credit: PASCALE PEREZ-RUBIN)

Citrus industry in Israel

Israel’s citrus industry dates back to 1882 when immigrants began to establish small orchards in the early stages of the First Aliyah. The industry currently comprises about 2,800 local growers, while taking up approximately 4.5% of Israel’s total agricultural acreage. The country not only relies on the local citrus growth for its domestic market, but a whopping 66% of all citrus is exported, which makes the industry an indispensable contributor to Israel’s economy. \

“The application of insecticide treatments [seemed] to have brought the outbreak under control by November,” reported Pre-HLB, a Europe-based group with a joint objective of protecting the EU and the rest of the world from HLB disease drivers. “The onset of winter [in 2021 and 2022] also helped to reduce the insect population, which is likely to multiply again in early spring.” 

Last January, the Ministry of Agriculture held an emergency discussion to formulate a strategy to contain and eventually exterminate the outbreak. They decided to regularly spray infected plots over the next year and continuously monitor the status of the outbreak through tests inside and outside the affected area. These operations continue even today, more than a year after the pest first appeared within Israel's borders.

The high population levels of insects shown by the initial tests suggested that an additional undetectable population of the insects existed in Israel at the time. For over a year there were no reports of the bacterium or the pests spreading. 

However, the Ministry of Agriculture recently detected an invasion of the Asian citrus psyllid in private yards that reached as far as the Hula Valley area and Kibbutz Dan. The insects have been spreading not only through citrus plants but also through the popular Israeli decorative plant—Orange Jessamine (Murraya paniculata).

"This situation, in which the infection invades outside agricultural land into the settlements, makes it difficult to carry out targeted and immediate actions,” said Shlomit Tzioni, Director of Plant Protection and Inspection Services at the Ministry of Agriculture. “The virus is relatively easy to detect, using a few simple rules. Together we can help the citrus growers in their fight against the new pest, and burn it from our borders.”