Spider Venom as a Bee-Friendly Pesticide?

Unlike the orb-weavers above, this is a male funnel web spider

A male funnel web spider

Given the negative impacts conventional pesticides are thought to have on bees, many people are eager to find an alternative way to control pest populations. One study that piqued some interest last summer was that a peptide in spider venom could be a bee-friendly pesticide (Nakasu et al 2014).

This “biopesticide” uses a peptide from the Australian funnel web spider’s (Hadronyche versuta) venom, and a component from the snowdrop plant (Galanthus nivalis)* to generate a substance that is toxic to many key agricultural pest species, but is harmless to bees and humans (even in very high doses).  The hope is that this kind of pesticide will be highly specific, thereby eliminating undesirable non-target effects on beneficial species.

IMG_9949

Snowdrops

There were a lot of nice parts of this study, for example, they also studied sublethal effects to see whether it changed foraging behaviour, learning, and memory, or caused the bees to be disoriented (it did not).

There are also a couple of problems with this study, one of which is problematic throughout the pesticide dose-effect literature…they only studied the effects on the honeybee (Apis mellifera)**.  Indeed, our understanding of the lethality of various pesticides is based almost solely on studies of this one species of bee, when in fact there are over 20,000 species of bees.  So it’s very possible that this biopesticide could have big impacts on, say, mason bees, or alkali bees, or even bumblebees.

It’s also a little unclear exactly which pest species would be affected, although the authors cite a 90-100% lethality on lepidopteran larvae, and cites studies that show an effect on the cotton bollworm (Helicoverpa armigera), common fruit fly (Drosophila melanogaster), and the cockroach (Periplaneta americana) (Nakasu et al 2014).  Obviously, only one of those is an agricultural pest, so more studies should be done.

That said, I feel that biopesticides like this have a big potential to help mediate the pesticide problem of large scale agriculture…just not by themselves.  I like this quote from one of the authors, Angharad Gatehouse, “What we need is an integrated pest management strategy and insect-specific pesticides will be just one part of that.” (source)

*The snowdrop protein acts as a carrier that allows the biopesticide to be active when ingested by the target pest species rather than injected via spider fangs.

*Studies of the effects of pesticides on other bees exist but not nearly at the same scale.

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