An intriguing study demonstrated that the common broom (Genista tinctoria) employs a unique and unusual defense mechanism against insect predators.
Primarily, they used a kind of water gun to shoot a high-pressure stream of liquid resin at the attacking insect.
This liquid is poisonous and repellent; in addition, the resins in the liquid turn solid when aerated and seal a small insect in a tomb.
The squirt gun preserves its chemicals in a network of canals in the leaf.
However, when an insect bites a leaf canal, the liquid gushes out as far as 1.5 metres, submerging a small insect in the worst scenarios.
On the contrary, the larger insects that survive the attack mitigate reduced growth and longevity.
This particularly showed the arms race between plant and insect that has been going on for millions of years.
It has been observed that some species of beetle have deciphered the plant’s defense mechanism gun by carefully grazing a series of small notches in the leaf.
The study further suggests that natural selection drives the development of potent defenses in the plants.
Consequently, it has been observed that some beetles will spend up to an hour deactivating the leaf’s defenses before eating it.
Additionally, the insects may later suffer slow growth and an early death.
However, the insect’s reproductive success suggests that the evolutionary race is still active.
