TY - JOUR

T1 - The life of a dead ant -the expression of an adaptive extended phenotype

AU - Andersen, Sandra Breum

AU - Gerritsma, Sylvia

AU - Yusah, Kalsum M.

AU - Mayntz, David

AU - Hywel-Jones, Nigel L.

AU - Billen, Johan

AU - Boomsma, Jacobus Jan

AU - Hughes, David Peter

N1 - Keywords: carpenter ants, histological cross sections, life-history evolution, Ophiocordyceps, sclerotia, behavioral manipulation.

PY - 2009

Y1 - 2009

N2 - Specialized parasites are expected to express complex adaptations to their hosts. Manipulation of host behavior is such an adaptation. We studied the fungus Ophiocordyceps unilateralis, a locally specialized parasite of arboreal Camponotus leonardi ants. Ant-infecting Ophiocordyceps are known to make hosts bite onto vegetation prior to killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings ca. 25 cm above the soil, where temperature and humidity conditions were optimal for fungal growth. Experimental relocation confirmed that parasite fitness was lower outside this manipulative zone. Host resources were rapidly colonized and further secured by extensive internal structuring. Nutritional composition analysis indicated that such structuring allows the parasite to produce a large fruiting body for spore production. Our findings suggest that the osmotrophic lifestyle of fungi may have facilitated novel exploitation strategies.  

AB - Specialized parasites are expected to express complex adaptations to their hosts. Manipulation of host behavior is such an adaptation. We studied the fungus Ophiocordyceps unilateralis, a locally specialized parasite of arboreal Camponotus leonardi ants. Ant-infecting Ophiocordyceps are known to make hosts bite onto vegetation prior to killing them. We show that this represents a fine-tuned fungal adaptation: an extended phenotype. Dead ants were found under leaves, attached by their mandibles, on the northern side of saplings ca. 25 cm above the soil, where temperature and humidity conditions were optimal for fungal growth. Experimental relocation confirmed that parasite fitness was lower outside this manipulative zone. Host resources were rapidly colonized and further secured by extensive internal structuring. Nutritional composition analysis indicated that such structuring allows the parasite to produce a large fruiting body for spore production. Our findings suggest that the osmotrophic lifestyle of fungi may have facilitated novel exploitation strategies.  

U2 - 10.1086/603640

DO - 10.1086/603640

M3 - Journal article

C2 - 19627240

VL - 174

SP - 424

EP - 433

JO - American Naturalist

JF - American Naturalist

SN - 0003-0147

IS - 3

ER -