|November 01, 2017|
A new wave of environmentally friendly pesticides will come from spider venom
|The vast majority of venomous spiders won't hurt you, but you definitely want to avoid members of the Australian funnel-spider family at all costs. They carry a cocktail of poisons that paralyze their prey by disrupting their nervous systems; some are so potent they can kill full-grown humans.|
Scientists have noticed the powerful punch some spider venoms pack, and have started looking to them for inspiration for all kinds of applications. Glenn King, a molecular biologist now at the University of Queensland in Brisbane, Australia, thinks they could change the agricultural industry. In 2005, he founded a biotech company called Vestaron, now based in Michigan, to use spider venom as the basis for better pesticides.
Vestaron focuses on developing natural insecticides from spider venom, either by recreating them in a lab or making them through genetically modified yeast. It's also working on genetically modifying crops so that the plants produce their own insect-killing chemicals. Vestron has received approval from the US Environmental Protection Agency to roll two of their Australian funnel spider venom-based products out in the beginning of 2018, to farmers growing ornamental flowers and vegetables, like tomatoes and cucumbers, in greenhouses.
Australian funnel spider venom is made of hundreds of short proteins called peptides, some of which disrupt cells in the central nervous system of a victim, causing paralysis. However, the venom is also filled with redundancies; while many of the peptides act in similar ways to each other, they're not quite the same. It's a biological insurance policy to guarantee that the spider's meal---sometimes much larger than the spider itself---will die before it can fight back. If one compound doesn't work, another might. So while some of these peptides are highly toxic for humans, others aren't at all. Some of these are only lethal for insects---making them the perfect natural insecticide if they could be mass produced.
Researchers at Vestaron broke down the peptides in Australian blue mountain funnel spider venom and isolated the ones that caused paralysis in insects, but not humans or other animals. They then isolated the genes in the spider that make these peptides and inserted them into yeast. The resulting genetically engineered yeast can be mass produced the insecticide components through fermentation, the same process that makes alcohol.
Spear-T and Spear-O---the two compounds that will be available for sale in the US starting in January---kill off four common greenhouse pests: whiteflies, thrips, aphids, and spider mites. Spear-C, which Vestaron expects to come out later in 2018, will work against certain types of caterpillars.
In lab tests, spider venoms have proven that they combine the best qualities of existing pesticides: they make for a powerful pest-killing punch with gentle effects on the plants themselves. Most synthetic pesticides kill upwards of 95% of the pests they're intended to kill. But they're harsh on plants: delicate leaves---particularly those on the sorts of ornamental flowers you're likely to find in a greenhouse---may wither away. Plants can generally tolerate biological pesticides, but they don't work nearly as well, protecting against 70% to 80% of pests. Spear products offer better protection and seem to be well-tolerated by the plants. And, because they're a new type of pesticide, insects haven't yet developed any resistance to them. (Though farmers will still have to rotate the venom-pesticides with other chemicals to make sure they don't cultivate literal superbugs.)
The company says that their products will also be less toxic to the growers and consumers than typical pesticides. Crops sprayed with Spear products can be harvested the same day; for most other pesticides, you need to wait anywhere between 24 hours and two weeks to ensure people don't accidentally ingest toxic chemicals.
For now, these products are only intended for use in indoor greenhouses. But they also show huge potential for use in open fields where they may come into contact with other forms of wildlife. Mammals, fish, birds, and even bees aren't bothered by them. Notably, bees aren't either. Historically, these pollinators have been wiped out from a common class of pesticides called neonicotinoids.
Right now, John Sorenson, a geneticist and CEO of Vestaron, estimates that the Vestaron products will be priced at the high end of currently available pesticides upward of $700 per gallon (these chemicals are heavily diluted before they're applied to crops, so a container goes a long way). But there's a growing demand for pesticides that are safer for both the environment and people, so Vestaron is confident the product will sell. "[Consumers are] really where the whole movement toward safer insecticides and safer chemistries comes from," Sorenson says.