Mineral body armor helps some leaf-cutting ants win fights with bigger kin
A species of leaf-cutting ant has a tough layer of calcite on its exoskeleton, experiments show
Leaf-cutting worker ants might look like they’d be helpless against an enemy soldier ant many times their size. But some of the smaller ants have a secret: Their entire body is coated with a thin but tough layer of mineral armor.
It’s the first time that this type of external, whole-body mineralization has been found in an adult insect, researchers report online November 24 in Nature Communications.
“I found rock ants,” evolutionary biologist Hongjie Li recalls telling his colleague, evolutionary biologist Cameron Currie, when the first experimental results of the hard coating came in. “I can still feel the excitement now,” Li says.
The discovery was serendipitous, says Currie, of the University of Wisconsin–Madison, who has been studying leaf-cutting ants for more than 20 years. His lab had been examining interactions between ants and their external microbes, which are thought to play a pivotal role in the ants’ farming practices (SN: 4/23/20), when the team encountered a white sheen on the exoskeletons of Acromyrmex echinatior worker ants. ...
Further chemical, X-ray and microscopic examinations revealed a thin layer of calcite containing high levels of magnesium.
To see how protective the armor is, the researchers tested the hardness of the ant exoskeleton by poking armored and nonarmored pieces until an indentation formed. Despite being a mere 7 percent of the overall thickness of the exoskeleton, the calcite coating at least doubles the exoskeleton’s hardness, the team found. ...
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https://www.sciencenews.org/article/leaf-cutting-ant-body-armor-mineral-exoskeleton-fight
A species of leaf-cutting ant has a tough layer of calcite on its exoskeleton, experiments show
Leaf-cutting worker ants might look like they’d be helpless against an enemy soldier ant many times their size. But some of the smaller ants have a secret: Their entire body is coated with a thin but tough layer of mineral armor.
It’s the first time that this type of external, whole-body mineralization has been found in an adult insect, researchers report online November 24 in Nature Communications.
“I found rock ants,” evolutionary biologist Hongjie Li recalls telling his colleague, evolutionary biologist Cameron Currie, when the first experimental results of the hard coating came in. “I can still feel the excitement now,” Li says.
The discovery was serendipitous, says Currie, of the University of Wisconsin–Madison, who has been studying leaf-cutting ants for more than 20 years. His lab had been examining interactions between ants and their external microbes, which are thought to play a pivotal role in the ants’ farming practices (SN: 4/23/20), when the team encountered a white sheen on the exoskeletons of Acromyrmex echinatior worker ants. ...
Further chemical, X-ray and microscopic examinations revealed a thin layer of calcite containing high levels of magnesium.
To see how protective the armor is, the researchers tested the hardness of the ant exoskeleton by poking armored and nonarmored pieces until an indentation formed. Despite being a mere 7 percent of the overall thickness of the exoskeleton, the calcite coating at least doubles the exoskeleton’s hardness, the team found. ...