The insect glue, produced from edible oils, was inspired by plants such as sundews that use the strategy to capture their prey. A key advantage of physical pesticides over toxic pesticides is that pests are highly unlikely to evolve resistance, as this would require them to develop much larger and stronger bodies, while bigger beneficial insects, like bees, are not trapped by the drops.
The drops were tested on the western flower thrip, which are known to attack more than 500 species of vegetable, fruit and ornamental crops. More than 60% of the thrips were captured within the two days of the test, and the drops remained sticky for weeks.
Work on the sticky pesticide is continuing, but Dr Thomas Kodger at Wageningen University & Research, in the Netherlands, who is part of the self defence project doing the work, said: “We hope it will have not nearly as disastrous side-effects on the local environment or on accidental poisonings of humans. And the alternatives are much worse, which are potential starvation due to crop loss or the overuse of chemical pesticides, which are a known hazard.”
The argument I’m making is that we should not call them chemicals when they don’t have the capacity to make chemical reactions.
An analogy could be how we use the word weed. We call unwanted plants weeds. If there is mint growing in your yard and you don’t want it, it’s a weed. If you sell your house and the next owner likes it that mint is not a weed anymore. It’s still mint (element) but no longer a weed (chemical).