The bumblebee outbreak threatening almond crops in Alicante continues to surge despite actions by the regional Ministry of Agriculture. Farmers are requesting swifter, more powerful responses to safeguard production. The pest, Eurytoma amygdali Enderlein, is a flying insect whose presence was first confirmed in Alicante in July 2017 and has since caused substantial financial losses. [Source: Valencian Agricultural Authority]
The almond wasp appeared on two farms in Biar, affecting an area of about 50 hectares. By 2019 the invasion had spread across the agricultural landscape, touching Pena Rubia de Villena and extending toward areas such as Sax-Castalla and Villena-Salinas. A year later, in June 2020, the Ministry of Agriculture warned that the pest’s advance was ongoing, with Foia de Castalla and parts of the Upper and Middle Vinalopó adding new zones of spread within Alicante and Marina Baixa. [Source: Regional Agricultural Reports]
Exactly two weeks ago, in March 2022, the Department of Agriculture’s Phytosanitary Division detected the first adult wasp specimens on almonds from the previous campaign in several Marina Baixa farms. Technicians explained that the pest’s cycle varies by farm, so treatments should be timed to target adults, typically four to five days after their emergence. Authorized pesticides include 79% paraffin oil, lambda-cyhalothrin at 1.5%, 2.5% and 10%, Pyrethrins at 4%, and Spirotetramate at 10%. [Source: Ministry phytosanitary guidance]
New announcement from the Ministry at Marina Baixa
In 2020 the Agriculture Ministry updated the pest status for the Valencian Community, with ongoing monitoring to issue treatment advisories aimed at reducing damage from the wasp. This ongoing effort continued through 2022 in Low Marina and High Palancia of Castellón. [Source: Community Agricultural Updates]
To confront this new field threat, Ministry technicians hold regular meetings with cooperative managers. There have been two gatherings this year, in Pinoso and Requena. [Source: Regional Planning Updates]
A key obstacle to eradicating the pest is abandoned almond groves where the wasp can overwinter and breed. When a complaint is received, Conselleria requests immediate phytosanitary action to curb spread, and affected owners may uproot and burn trees to prevent the pest from taking hold elsewhere. Noncompliance can lead to penalties. [Source: Agricultural Compliance Guidelines]
Farm groups advocate for funding allocations to cover these costs, though the request remains unresolved. [Source: Agricultural Coalition Statements]
Another threat to the field after Xylella
In summary, the Alicante countryside faces another challenge after the long-standing impact of Xylella fastidiosa, a bacteria that has devastated olive and citrus trees in recent years. [Source: Plant Health Reports]
Unlike some other pests, the bumblebee plague does not immediately degrade the tree itself, which helps farmers avoid abrupt losses. As the pest matures, it lays eggs inside almonds and the larvae feed on kernels until they reach the chrysalis stage, making early detection difficult. The true extent of damage is often apparent only at harvest or in the weeks leading up to it. [Source: Agricultural Diagnostics]
Another distinguishing factor is the limited use of plant protection products, which are registered by the Ministry of Agriculture, Fisheries and Food. These products are expensive, and manufacturers must be informed about their necessity for the industry. Infected kernels cannot be used for animal feed, stove fuel, or other applications. [Source: Pest Management Registry]
Valencia researchers continue testing a range of phytosanitary, ecological, and biological treatments aimed at halting the insect’s progress and eliminating its population. There is cautious optimism about releasing a predatory wasp that would not harm the ecosystem, but this approach remains experimental. [Source: University of Valencia Projects]
Experts warn that Hymenoptera could trigger a fast-spreading outbreak that is hard to detect and control in time. A comprehensive study by regional agricultural groups emphasizes raising awareness and advising wasp-affected ranchers to collect and burn mummified almonds. Authorities at the Community, provincial, and municipal levels are expected to press for the removal of all almond trees planted in abandoned fields to stop the pest from spreading. [Source: Agricultural Research Findings]
These dispersed farm hotspots require decisive action for the control measures to succeed. [Source: Field Safety Assessments]
Plague reached the Valencian Community in 2016
The almond wasp was first identified in Spain in 2010 and is believed to have arrived through unregulated imports from South Asia, with the earliest detection in Albacete. By February 2016 evidence of Hymenoptera appeared in various parts of the Valencian Community, notably Cofrentes-Ayora Valley and La Plana Utiel-Requena. Eighteen months later, the pest reached Alto Vinalopó in Alicante. [Source: Historical Pest Records]
Adult females lay eggs inside growing almonds, where larvae develop by feeding on the developing nuts through the season. The almonds become unusable as larvae mature into pupae and adults emerge later. The cycle begins anew in April when females lay fresh eggs, potentially 50 to 100 per nut, marking the critical window for eradication efforts. [Source: Agricultural Lifecycle Studies]