01 Apr Spider Venom as an Insecticide
Evidence is accumulating that commonly used pesticides are linked to the decline of pollinator populations. Several reports of adverse effects of neonicotinoids on beneficial pollinating insects have recently resulted in a controversial ban on their use by the European Commission. These “neonics” currently make up 24% of the world insecticide market. 90% of the world’s plants are directly reliant on pollinators to survive.
Protecting crops often means using synthetic chemical insecticides, sometimes with collateral damage to humans and other non-target animals. Even newer pesticides that are safe for mammals are killing helpful pollinators, like bees.
Insect pollination is an important ecosystem service but is also essential for fruit set in many crop species, contributing to 35% of global food production in approximately 70% of crops.
Developing insecticides that pose negligible risks to beneficial organisms such as honeybees is desirable and timely.
Scientists have discovered that the venom of the world’s deadliest spider will kill pests but won’t harm bees. This strategy uses certain neuroactive proteins linked to a “carrier” protein that allows the “poison” to act orally. One such oral biopesticide, effective towards various insect pests is a combination of an insect-specific spider venom linked to material from Galanthus nivalis (common snowdrops). The spider is an Australian funnel spider, an eight-eyed, three-clawed spider that runs, swims and bites!
The spider venom acts as a calcium channel blocker. Certain tests were performed suggesting that this material is unlikely to cause detrimental effects on honeybees. Also, it indicated that these particular “biotoxins” targeting calcium channels are a potential alternative to conventional pesticides. Another study showed that they attack the central nervous system of agricultural pests such as aphids and caterpillars without harming honeybees.
Proteins from the spider venom, when combined with another carrier protein (called lectin from the snowdrop plant mentioned above), transports the toxin across the insects gut wall. The calcium channels that carry ions into the nerve cells are disrupted and this disruption kills the bugs.
One of the tests to see if this pesticide would harm beneficial bees was performed in England in 2014 by Newcastle University. Calcium channels are linked to learning and memory in honeybees who must learn and remember various floral traits to help them find food and return to their hives. Honeybees in this test were exposed to varying doses of the spider venom through ingesting it in a sugary solution. Some had it just once and others ate massive amounts over the course of seven days. Some were actually injected directly with the solution.
Ingesting the spider venom biopesticide had only a slight effect on the honeybee survival, probably because of the differences in channel receptors between various insect species.
On the downside, this new pesticide has not been tested on a wide variety of non-target species such as native bees, lady beetles, lacewings and hover flies. Also, these substances are “recombinant fusion proteins” which means they are genetically modified, created artificially by DNA technology. Who could possibly know what the effect of these substances could create in the future to our environment.
While humans have not ingested the pesticide, the scientific evidence suggests that there is absolutely no danger to humans if they did. The toxins target the central nervous system of insects but not mammals.
After 11 years of research, Vestaron Corporation, a spin-off of the University of Connecticut has received approval from the U.S. Food and Drug Administration to start selling the venom-based pesticides. These pesticides are actually produced in Kalamazoo, Michigan. Actually, no deadly spiders are located there. The company created a process that allows them to make a synthetic version, thus, no deadly spiders need to be “milked”.
The products will be sold by the brand name “SPEAR” (species at risk). At the time of this writing, they are being marketed only to farmers and greenhouse growers.
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