RT Journal Article
SR Electronic
T1 Ecology and population genetics of the parasitoid <em>Phobocampe confusa</em> (Hymenoptera: Ichneumonidae) in relation to its hosts, <em>Aglais</em> species (Lepidoptera: Numphalidae)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.05.27.115212
DO 10.1101/2020.05.27.115212
A1 Hélène Audusseau
A1 Gaspard Baudrin
A1 Mark R. Shaw
A1 Naomi L.P. Keehnen
A1 Reto Schmucki
A1 Lise Dupont
YR 2020
UL http://biorxiv.org/content/early/2020/05/27/2020.05.27.115212.abstract
AB The biology of parasitoids in natural ecosystems remain very poorly studied, while they are key species for their functioning. Here we focused on Phobocampe confusa, a vanessines specialist, responsible for high mortality rates in very emblematic butterfly species in Europe (genus Aglais). We studied its ecology and genetic structure in connection with those of its host butterflies in Sweden. To this aim, we gathered data from 428 P. confusa individuals reared from 6094 butterfly larvae (of A. urticae, A. io and in two occasions of Araschnia levana) collected over two years (2017 and 2018) and 19 sites distributed along a 500 km latitudinal gradient. We found that P. confusa is widely distributed along the latitudinal gradient. Its distribution is constrained over time by the phenology of its hosts. The large variation in climatic conditions between sampling years explains the decrease in phenological overlap between P. confusa and its hosts in 2018 and the 33.5% decrease in the number of butterfly larvae infected. At least in this study, P. confusa seems to favour A. urticae as host: while it parasitized nests of A. urticae and A. io equally, the proportion of larvae is significantly higher for A. urticae. At the landscape scale, P. confusa is almost exclusively found in vegetated open land and near deciduous forests, whereas artificial habitats are negatively correlated with the likelihood of a nest to be parasitized. The genetic analyses on 89 adult P. confusa and 87 adult A. urticae using COI and AFLP markers reveal a low genetic diversity in P. confusa and a lack of population genetic structure in both species, at the scale of our sampling. Further genetic studies using high-resolution genomics tools will be required to better understand the population genetic structure of P. confusa, its biotic interactions with its hosts, and ultimately the stability and the functioning of natural ecosystems.Competing Interest StatementThe authors have declared no competing interest.