Slunéčkovitých representative of the family was still around the world discovered in detail more than 5000. Not all "ladybird" decorated their elytra bright colors and dots. Why? As shown by studies of naturalists from Exeter and Cambridge, the relationship between the dots and bright colors reflect only their cuteness, but also warns predators before defensive intensity poison ladybugs.
Ladybugs may be just a seven red dots. Many species boasts a striking orange and yellow colors, but also encounter "masked" the representative species of brown elytra. Lina María, Arenas, a student from the Centre for Ecology and Conservation at the University of Exeter, brought the color variations ladybirds order. As he says: "The color of elytra ladybugs clearly reflects how much toxic to their surroundings are."
In order to substantiate his hypothesis, Arenas solid arguments, he tested the strength of poison hrotnatkách, small aquatic crustaceans. Toxic substances obtained from five in Britain, the most common species of ladybugs dissolve in beakers and then watched what will hrotnatek mortality. And indeed, the brighter coloration was observed species of ladybugs, the toxic substance has been their defense.
Much more interesting is that the birds, the main predators floating ladybugs with this warning signal learned well understood. It's the first of all the fact that ladybugs are sincere and their toxicity intentionally lie. That their signal transmits real information about the concentration of toxic alkaloids (which makes them bitter, inedible to poisonous), birds, after several attempts to brightly colored ladybugs can be rather careful.
"Inconspicuous gray-brown beetle forest actually has a low concentration of defense compounds, and so prefer to bet on, should not be too visible," says Arenas mechanism. "While considerably more confident and striking dvoutečné ladybug flies freely in the air, because it has strong defenses against predators. "
Together with my colleague Martin Stevens then tried another response birds. First elytra were to take different kinds of ladybugs camera sensitive to UV rays, so you can view them "bird eyes". Then produced several mockups ladybugs corresponding to their different timbre toxicity and submit this delicacy birds. Birds really preferentially chose the ladybird, which honestly informed that they are not poisonous.
Author: Radomír Dohnal
Source: Ekolist.cz