TY - JOUR

T1 - Workers of Acromyrmex echinatior leafcutter ants police worker-laid eggs, but not reproductive workers

AU - Dijkstra, Michiel B.

AU - van Zweden, Jelle Stijn

AU - Dirchsen, Maria

AU - Boomsma, Jacobus Jan

PY - 2010

Y1 - 2010

N2 - Nonreproductive workers of many eusocial Hymenoptera 'police' the colony, that is, they attack reproductive sister workers or destroy their eggs (unfertilized; developing into haploid males). Several ultimate causes of policing have been proposed, including (1) an increase in colony productivity, applicable if reproductive workers work less, or (2) an increase in worker-to-male relatedness, applicable if within-colony relatedness is low. To explain the distribution of policing across taxa, the explanatory power of these and other potential ultimate causes should be assessed separately. One of the few species for which this can be done is the leafcutter ant Acromyrmex echinatior. We previously demonstrated that colony productivity incentives (and sex ratio incentives) are minimal here, while relatedness incentives are strong because queens are highly multiply mated. Overcoming technical difficulties peculiar to leafcutter ants, we introduced reproductive versus nonreproductive workers and batches of queen-laid versus worker-laid eggs into experimental colony fragments and observed their fate. Our main finding was that workers policed by selectively destroying worker-laid eggs, but without attacking reproductive workers. We infer that relatedness incentives are the most likely ultimate cause of the evolutionary maintenance of worker-egg policing in A. echinatior. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved

AB - Nonreproductive workers of many eusocial Hymenoptera 'police' the colony, that is, they attack reproductive sister workers or destroy their eggs (unfertilized; developing into haploid males). Several ultimate causes of policing have been proposed, including (1) an increase in colony productivity, applicable if reproductive workers work less, or (2) an increase in worker-to-male relatedness, applicable if within-colony relatedness is low. To explain the distribution of policing across taxa, the explanatory power of these and other potential ultimate causes should be assessed separately. One of the few species for which this can be done is the leafcutter ant Acromyrmex echinatior. We previously demonstrated that colony productivity incentives (and sex ratio incentives) are minimal here, while relatedness incentives are strong because queens are highly multiply mated. Overcoming technical difficulties peculiar to leafcutter ants, we introduced reproductive versus nonreproductive workers and batches of queen-laid versus worker-laid eggs into experimental colony fragments and observed their fate. Our main finding was that workers policed by selectively destroying worker-laid eggs, but without attacking reproductive workers. We infer that relatedness incentives are the most likely ultimate cause of the evolutionary maintenance of worker-egg policing in A. echinatior. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved

KW - Acromyrmex echinatior

KW - cost of worker reproduction

KW - leafcutter ant

KW - multiple queen mating

KW - reproductive self-restraint

KW - worker policing

KW - FUNGUS-GROWING ANTS

KW - APIS-MELLIFERA-CAPENSIS

KW - EUSOCIAL HYMENOPTERA

KW - INSECT SOCIETIES

KW - SOCIAL INSECTS

KW - MALE PARENTAGE

KW - SEX-ALLOCATION

KW - FORMICA-FUSCA

KW - COLONY SIZE

KW - CLONAL ANT

U2 - 10.1016/j.anbehav.2010.06.011

DO - 10.1016/j.anbehav.2010.06.011

M3 - Journal article

VL - 80

SP - 487

EP - 495

JO - Animal Behaviour

JF - Animal Behaviour

SN - 0003-3472

IS - 3

ER -