Plants for their own benefit turn caterpillars into cannibals

We often think that plants are very peaceful, and they passively wait for them to eat any caterpillar. However, some plants have developed a very ingenious and diabolical way of fighting their herbivorous enemies.

Defensive substances

A new study demonstrated how some plants protect themselves from herbivores: they make them turn into cannibals. The results of the study, published in the journal Nature: Ecology and Evolution, have shown that tomato plants (Lycopersicon lycopersicum) produce defensive chemicals that cause dangerous caterpillars (beet worms) to eat each other.

As soon as the caterpillars begin to eat the leaves of these plants, the latter release an organic compound called methyl-jasmonate. This substance makes the plant very harmful to the insect, forcing it to resort to cannibalism.

"Many insects, as you know, become cannibals, if it is necessary for their survival," says the author's statement in the statement of Professor John Orrock. - From the plant's point of view, this is definitely the desired result - to make the herbivores eat each other. Insects-cannibals not only benefit the plant by killing like herbivores, but also no longer show interest in the leaves themselves, since they have already satisfied their hunger with other caterpillars. "

However, methyl-jasmonate has one more effect. When this connection begins to be developed, it acts as an emergency siren for neighboring plants, warning them of the approach of enemies. This stimulates other plants to use all means for self-defense and begin to produce their own reserves of methyl-jasmonate.

Features of cannibalism

It may seem strange that the caterpillars forget about their plant diet so quickly and start hunting each other, but researchers explain that cannibalism is a double-edged sword that can be both beneficial to the survival of the species and harm it.

"Cannibal, in fact, finds a source of" ideal food, "- explains in his statement, Associate Professor Bret Elderd. - A cannibal victim has all the proportions of proteins and trace elements that he needs, because she is the same as he. The disadvantage, however, is that the victim is also the ideal host for any pathogens or parasites that can also live in the cannibal system. Thus, cannibalism is a rather dangerous phenomenon, since it carries with it a high probability of infection with certain diseases if the individual feeds on representatives of its own species. "

Idial Weapons

Given this, researchers want to study the characteristics of cannibalism among insects to understand whether it helps or prevents the spread of pathogens. If it contributes to this, then the plant protection mechanism will prove to be even more effective than scientists ever assumed.