Laterality of leaf cutting in the attine ant Acromyrmex echinatior

Social insects have evolved a suite of sophisticated defences against parasites. In addition to the individual physiological immune response, social insects also express ‘social immunity’ consisting of group-level defences and behaviours that include allogrooming. Here we investigate whether the social immune response of the leaf-cutting ant Acromyrmex echinatior reacts adaptively to the virulent fungal parasite, Metarhizium anisopliae . We ‘immunized’ mini-nests of the ants by exposing them twice to the parasite and then compared their social immune response with that of naive mini-nests that had not been experimentally exposed to the parasite. Ants allogroomed individuals exposed to the parasite, doing this both for those freshly treated with the parasite, which were infectious but not yet infected, and for those treated 2 days previously, which were already infected but no longer infectious. We found that ants exposed to the parasite received more allogrooming in immunized mini-nests than in naive mini-nests. This increased the survival of the freshly treated ants, but not those that were already infected. The results thus indicate that the social immune response of this leaf-cutting ant is adaptive, with the group exhibiting a greater and more effective response to a parasite that it has previously been exposed to.

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Examination of the immune responses of males and workers of the leaf-cutting ant Acromyrmex echinatior and the effect of infection

Insectes Sociaux ◽

10.1007/s00040-005-0809-x ◽

2005 ◽

Vol 52 (3) ◽

pp. 298-303 ◽

Cited By ~ 49

Author(s):

B. Baer ◽

A. Krug ◽

J. J. Boomsma ◽

W. O. H. Hughes

Keyword(s):

Immune Responses ◽

Leaf Cutting ◽

Acromyrmex Echinatior

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Biogenic amines are associated with worker task but not patriline in the leaf-cutting ant Acromyrmex echinatior

Journal of Comparative Physiology A ◽

10.1007/s00359-013-0854-2 ◽

2013 ◽

Vol 199 (12) ◽

pp. 1117-1127 ◽

Cited By ~ 12

Author(s):

Adam R. Smith ◽

Mario L. Muscedere ◽

Marc A. Seid ◽

James F. A. Traniello ◽

William O. H. Hughes

Keyword(s):

Biogenic Amines ◽

Leaf Cutting ◽

Acromyrmex Echinatior

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Sperm mixing in the polyandrous leaf‐cutting ant Acromyrmex echinatior

Ecology and Evolution ◽

10.1002/ece3.1176 ◽

2014 ◽

Vol 4 (18) ◽

pp. 3571-3582 ◽

Cited By ~ 7

Author(s):

Marlene Stürup ◽

David R. Nash ◽

William O. H. Hughes ◽

Jacobus J. Boomsma

Keyword(s):

Leaf Cutting ◽

Acromyrmex Echinatior

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Queens of the inquiline social parasite Acromyrmex insinuator can join nest-founding queens of its host, the leaf-cutting ant Acromyrmex echinatior

Insectes Sociaux ◽

10.1007/s00040-021-00819-3 ◽

2021 ◽

Author(s):

J. Howe ◽

M. Schiøtt ◽

J. J. Boomsma

Keyword(s):

Social Parasite ◽

Fungus Garden ◽

Symbiotic Fungus ◽

Metapleural Glands ◽

Leaf Cutting ◽

Nest Founding ◽

Incipient Colony ◽

Incipient Colonies ◽

Worker Caste ◽

Acromyrmex Echinatior

AbstractQueens of the inquiline social parasite Acromyrmex insinuator are known to infiltrate mature colonies of Acromyrmex echinatior and to exploit the host’s perennial workforce by producing predominantly reproductive individuals while suppressing host reproduction. Here we report three cases of an A. insinuator queen having joined an incipient colony of A. echinatior that contained only the founding host-queen and her small symbiotic fungus garden. We conjectured that 1:1 host-inquiline co-founding—a phenomenon that has only rarely been reported in ants—may imply that the presence of an A. insinuator queen may incur benefits to the host by increasing survival of its incipient colonies. We observed that the parasite queens neither foraged nor defended the nest against intruders. However, the parasite queens interacted with the host and fungus in a way that could be consistent with grooming and/or with contributing eggs. These observations may help explain why A. insinuator queens have maintained metapleural glands, even though they are smaller than those of host queens, and why A. insinuator has lost the large foraging worker caste but not the small worker caste.

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Biomineral armor in leaf-cutter ants

Nature Communications ◽

10.1038/s41467-020-19566-3 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Hongjie Li ◽

Chang-Yu Sun ◽

Yihang Fang ◽

Caitlin M. Carlson ◽

Huifang Xu ◽

...

Keyword(s):

Protective Role ◽

In Vitro Synthesis ◽

Anatomical Structures ◽

Magnesium Calcite ◽

Leaf Cutting ◽

High Magnesium Calcite ◽

Acromyrmex Echinatior

AbstractAlthough calcareous anatomical structures have evolved in diverse animal groups, such structures have been unknown in insects. Here, we report the discovery of high-magnesium calcite [CaMg(CO3)2] armor overlaying the exoskeletons of major workers of the leaf-cutter ant Acromyrmex echinatior. Live-rearing and in vitro synthesis experiments indicate that the biomineral layer accumulates rapidly as ant workers mature, that the layer is continuously distributed, covering nearly the entire integument, and that the ant epicuticle catalyzes biomineral nucleation and growth. In situ nanoindentation demonstrates that the biomineral layer significantly hardens the exoskeleton. Increased survival of ant workers with biomineralized exoskeletons during aggressive encounters with other ants and reduced infection by entomopathogenic fungi demonstrate the protective role of the biomineral layer. The discovery of biogenic high-magnesium calcite in the relatively well-studied leaf-cutting ants suggests that calcareous biominerals enriched in magnesium may be more common in metazoans than previously recognized.

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