An invasive hornet species could have a disastrous impact on honey bee populations and crops that rely on pollination.
Along with the global pandemic and devastating fires in California, the US looks set to do battle with the giant Asian hornet.
The species of hornet, Vespa mandarinia, has been found in Washington State; raising concern across the whole country as it is known to have devastating impact on honeybee populations. Researchers in Chile have conducted studies to try and estimate the potential spread of the insect, its impact on honey bees and the economic loss linked to bee-pollinated crops.
Publishing their findings in the journal Pest Management Science the researchers conclude that the hornet could colonise the US from the east to the west, threatening and estimated income of up to $101million for hive derived products and bee pollinated crop production.
The researchers say that their findings prompt the need for monitoring actions and planning at different administrative levels to avoid a potential spread. Highlighting the devastating impact of such invasive species, the researchers point to the appearance of the yellow-legged hornet (Vespa velutina Lepeletier) which had a serious impact on honeybees after it was accidentally introduced into Europe. Found initially in France during 2004, it then colonised Spain, Belgium, Portugal, Italy, Germany, the UK, reaching the Netherlands in 2017. Actions taken to control the hornet in Europe have been ‘expensive and inefficient,’ the researchers say.
Vespa mandarinia has been described as a species highly sensitive to heat and extreme climate conditions. Using Ecological Niche Monitoring (ENM) the researchers were able to estimate the environmental niche requirement of the species and project these requirements into new zones. This approach has allowed the prediction of areas that could potentially be invaded. Seven states: Massachusettes, Connecticut, Rhode Island, New Jersey, Delaware, Maryland and New Hampshire could have more than half of their incomes derived from honey bees under threat. Bee pollinated crops that represent the biggest risk to income include cotton, blueberries and tobacco.
A strategy to sample and monitor the invasive hornet would involve the use of citizen science programmes, which is useful as the species that needs to be monitored can be easily identified. In terms of control the US Department of Agriculture has proposed a series of measures including lethal and passive traps as well as a series of effective pesticides and scalable control actions.
Pest Management Science DOI:10.1002/ps.6063