Fluctuating asymmetry in an insect host: A big role for big parasites?

Citation
F. Thomas et al., Fluctuating asymmetry in an insect host: A big role for big parasites?, ECOL LETT, 1(2), 1998, pp. 112-117
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
1
Issue
2
Year of publication
1998
Pages
112 - 117
Database
ISI
SICI code
1461-023X(199809)1:2<112:FAIAIH>2.0.ZU;2-2
Abstract
Parasites are expected to be associated with host developmental instability because developmentally unstable hosts may be more susceptible to, or more frequently exposed to, parasitic infections compared with developmentally stable ones, or because parasites may directly disrupt host development. In this study, we analysed the relationship between developmental stability i n the weta Pleioplectron simplex (Orthoptera) and infections by hairworm an d mermithid parasites. These parasites have a long development in their hos t and the size of adult worms exceeds the length of the host by a considera ble amount (15-20 cm). For one character (femora) we found that fluctuating asymmetry was significantly higher in parasitized individuals compared wit h unparasitized ones, in each of two samples collected in different years. Because no relationship was observed between the level of fluctuating asymm etry and the parasite size or number, however, infection by hairworm and me rmithid parasites could be more a consequence of developmental instability than a cause. For other characters (tibia, external and internal spines of femora), the level of fluctuating asymmetry between parasitized and unparas itized individuals was not significantly different. Our results are discuss ed in relation to ecological constraints met by hairworm and mermithid para sites to complete their life cycle.