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06/09/2024
Research
4 min

Genetic analyses shed light on the origin of the small hive beetle recently reported on Reunion Island

The small hive beetle is a parasite of honey bees. It was first detected on Reunion Island in July 2022. Genetic analyses conducted by ANSES's Sophia Antipolis Laboratory have revealed that the specimens that arrived on the island are similar to those found in China and the Philippines.

A parasite that is decimating bee colonies

When the small hive beetle (Aethina tumida) is present in apiaries, it can weaken or cause the death of entire bee colonies. This beetle feeds on bee larvae, honey and bee bread (a naturally fermented mixture of pollen pellets, honey and lactic ferments used to feed bee larvae). It originated in sub-Saharan Africa, but has spread around the world to America, Oceania, Asia and, around a decade ago, Europe, via southern Italy. In July 2022, it was detected for the first time in France on Reunion Island in the Indian Ocean.

The Bee Diseases Unit of ANSES's Sophia Antipolis Laboratory, which is the national and European reference laboratory for bee health, conducted a genetic analysis to determine the geographical origin of the specimens detected on Reunion Island. The scientists sequenced the genome of two specimens collected on the island at the start of the introduction and then compared the results with the available and known genetic sequences of other populations of small hive beetles. This showed that the beetles found on Reunion Island were genetically closer to those found in China and the Philippines than to those from Africa, Europe or America. "However, just because they belong to the same genetic group does not mean that the specimens introduced to Reunion came from China or the Philippines", cautions Véronique Duquesne, deputy head of the National Reference Laboratory for bee health.

Humans probably behind the introduction

There are several assumptions to explain the insect's introduction to the island: "the small hive beetle can fly, but with an island, it is more likely that its introduction is due to human activity", explains the scientist. "Several routes of introduction are possible, including illegal imports of bees and the considerable trade linked to maritime transport." In particular, the insect is already present in Madagascar, as well as in Mauritius since 2017. Both countries are close to Reunion Island. The small hive beetles in Madagascar belong to a different genetic group, which includes specimens originating from Africa. The genetic profile of the beetles in Mauritius is still being studied.

Information from epidemiological field investigations can complement genetic studies and help determine the origin of the introduction. The aim of these investigations is to identify the possible source of an introduction and determine its date by collecting a number of details about the apiaries where cases were discovered, such as beekeeping practices (exchange of equipment or bees, transhumance, etc.), apiary location and immediate environment. To date, the epidemiological investigations carried out on Reunion Island have not been able to identify the origin of the introduction.

Measures to prevent its arrival in metropolitan France

The proposed eradication strategy, which consisted in destroying hives infested with the beetle and prohibiting the movement of hives within a 10-kilometre radius of the detection sites, has failed to eliminate the insect from the island.

The small hive beetle is not currently found in mainland France or Corsica, but has been established in southern Italy since 2014. Measures are therefore in place to prevent its arrival in metropolitan France. In particular, it is forbidden to bring in bees, bumblebees, unprocessed bee products and by-products and beekeeping equipment from infested areas. Compliance with all the measures put in place is vital to limit the risk of introduction to France. Early detection is essential to prevent the parasite from becoming established. Regular visual inspection of bee colonies ensures that prompt action can be taken. In the event of any suspicion, the relevant Departmental Directorate for the Protection of Populations (DDPP), or the veterinarian who monitors the hives, should be alerted as soon as possible.

Find out more

Read the scientific publication on the genetic analysis of the small hive beetle from Reunion Island

See the information from the Ministry of Agriculture and Food Sovereignty on Aethina tumida

Read our opinion on the management strategy for the small hive beetle on Reunion Island (PDF in French)
 
Read our opinion on assessing the relevance of continuing the eradication strategy for the small hive beetle on Reunion Island (PDF in French)