Consumption of fungi-infected fallen pear leaves by the common woodlouse

Summary

Consumption of infected plant tissues by decomposing organisms is an important part of ecosystem
services. We tested how the common woodlouse (Porcellionides pruinosus, Isopoda: Oniscidea) may
contribute to the decomposition process in a laboratory experiment in which Mycosphaerella pyri-infected
pear leaves with or without the aecia of Gymnosporangium sabinae were offered as food. We recorded the
loss of healthy and infected leaf tissues. Isopod survival rate was also monitored. We found (1) a certain
pattern of preference in the consumption of infected leaf material; and (2) that the presence of G. sabinae
reduced leaf consumption but had no effect on the ingestion of Mycosphaerella-infected spots; and (3) the
mortality of P. pruinosus was adversely influenced by G. sabinae, but the results were highly dependent on
confinement conditions. Our results suggest that woodlice consume plant pathogenic fungi, and therefore
offer the ecosystem service of neutralizing infective plant remnants during decomposition.