Spider venom offers pesticide hope for bees
4 June 2014 by Alex Peel
A new pesticide, created using spider venom and natural chemicals from snowdrop plants, appears to be harmless to honeybees, a new study has concluded.
The formula, which is toxic to a number of key insect pests, shows little sign of damage to honeybee survival rates or key brain functions such as learning and memory.
And it seems that honeybee larvae are able to break the chemical down in their gut, keeping them safe from any harmful effects.
Scientists hope that it could provide a safe alternative to neonicotinoid pesticides, which in recent years have been implicated in honeybee declines.
"Our findings suggest that Hv1a/GNA is unlikely to cause any detrimental effects on honeybees," says Professor Angharad Gatehouse of Newcastle University, who supervised the project.
"Previous studies have already shown that it is safe for higher animals, which means it has real potential as a pesticide and offers us a safe alternative to some of those currently on the market."
The chemical fusion is made using the toxic venom of the Australian funnel web spider and plant protein from snowdrops. In its pure form, the venom is one of the most toxic in the world, and can be deadly to humans.
In the lab, the team fed the formula to honeybees at a variety of doses, some substantially higher than they would ever encounter in their natural environment, over a period of seven days.
Throughout that time, they tested the bees' memory, recording any changes in behaviour. Memory and learning are vital to the bees' ability to locate and exploit food sources.
If we destroy the biodiversity of pollinators then it will be irrelevant how effective our pesticides are because we won't have any crops to protect
- Dr Geraldine Wright, Newcastle University
Even at high concentrations, the pesticide had only very minor effects on the bees' survival rates, and no measurable effect whatsoever on their ability to learn and remember.
A number of honeybee populations, a key pollinator of important food crops, have faced declines in recent years. Along with habitat loss and disease, pesticides have taken some of the blame.
Evidence has been mounting against a particular strand of pesticides called neonicotinoids, which are thought to harm bees' brain function. In December last year, the EU responded by introducing a two-year moratorium on the chemicals.
But there are fears that the alternatives could be even worse. In a lab study, one potential alternative - a pyrethroid - was found to reduce the size of bumblebees' offspring, posing a potential risk to colony success.
This new compound affects a different part of insects' brains to traditional pesticides, allowing it to target particular pest species more accurately. But Gatehouse warns that there is unlikely to be a single solution to the pesticide problem.
"There isn't going to be one silver bullet," she says. "What we need is an integrated pest management strategy and insect-specific pesticides will be just one part of that."
Her colleague at Newcastle University, and co-author on the paper, Dr Geraldine Wright, says finding new bee-safe pesticides is vital to our future food security.
"Around 90 per cent of the world's plants are directly or indirectly reliant on pollinators to survive," she explains. "If we destroy the biodiversity of pollinators then it will be irrelevant how effective our pesticides are because we won't have any crops to protect."
"There is now substantial evidence linking neonicotinoid pesticides to poor performance and survival in bees and what we need now is a clear directive from government to develop and introduce bee-safe alternatives."
The research is published today in the journal Proceedings of the Royal Society B.
Erich YT Nakasu, Sally M Williamson, Margin G Edwards, Elaine C Fitches, John A Gatehouse, Geraldine A Wright, and Angharad MR Gatehouse, 'Novel biopesticide based on a spider venom peptide shows no adverse effects on honeybees', Proceedings of the Royal Society B, 2014.