Spider venom project to protect crops from insects

And that is spider venom.

Professor Glenn King at The University of Queensland's Institute for Molecular Bioscience (Australia) has been developing insecticides based on spider venom.

As spiders are the "quintessential insect predator" it makes sense to explore the reasons why their venom is so potent.

His results have shown that spider venom can be used as a stand-alone insecticide or used to engineer insect-resistant crops. But before you have nightmares of crops infested by poisonous spiders let loose in our countryside to control insects, let me assure you that it will be a peptide – a chemical based on one component in the venom – that is used.

These venoms are a complex chemical cocktail of inorganic salts, small organic molecules, peptides and proteins that act together in the nervous system of the spider's prey, the insect.

Nature has developed and perfected this bio-insecticide over many millions of years, so spider venoms are an excellent source of natural insecticide compounds.

In addition, Prof King has discovered that spider-venom peptides are highly stable in the insect gut. This is important as it demonstrates the stability of these spider-venom peptides, and means that they should be stable during long periods of storage as well as in the field.

Moreover, when they do break down, they will degrade into innocuous amino acids that will not cause problems with crop residues.

However, one of the challenges to overcome is how to make sure the venoms enter the prey. In nature, what happens is that the spider uses a hypodermic needle-like fang that penetrates the protective exoskeleton.

Prof King is therefore looking at ways of using vectors to introduce the toxins or to encourage the target insects to ingest them.

Another promising option is to fuse spider venom peptides with a carrier protein that facilitates transport across the gut.

Products from spiders have a wide range of insect-killing abilities that prevent insects becoming resistant to spider bites, so researchers are investigating whether humans can mimic those compounds.

Because most spiders do not feed on a restricted prey type, their venoms have evolved to contain an array of compounds that target a broad spectrum of prey. Moreover, although some large spiders eat small vertebrates, very few are toxic to humans.

The project is still in its infancy but Prof King is hopeful that the outcomes will be of enormous long-term benefit to the cropping industry in Australia and around the world.

There are not a lot of insecticide products in the pipeline of commercialisation due to the prohibitive cost of bringing them to market and the length of time to achieve registration, so it is imperative we look at other options that are environmentally-friendly and sustainable. The research on spider venom is sponsored by the Australian Research Council and the Australian Grains Research and Development Corporation.

Heather Briggs is the former manager of an agricultural growers' co-op who now works in the agri-PR sector.