Plantwatch: The plant that shoots toxic liquid – and the insects trying to beat it | Plants
IInsects get a nasty surprise if they try to bite the leaves of bursera shrubs and trees: they use a kind of water gun to project a jet of liquid resin at high pressure onto the attacking insect. This liquid is perfectly repellent and toxic, but for good measure, the resins in the liquid can turn solid when exposed to air and trap a small insect in a grave.
The water gun stores its chemicals in a network of channels in the leaf. When an insect stings a leaf canal, the liquid gushes up to 1.5 meters, flooding the small insect with deadly secretions. Larger insects that survive the attack suffer reduced growth and life expectancy.
It’s an arms race between plants and insects that has been going on for millions of years, and in that time, some species of beetles have figured out how to pierce the plant gun, by carefully nibbling a series of small notches in the leaf. Some beetles spend up to an hour disarming the leaf before eating it, but despite this, the insects then suffer slow growth and premature death.
