Comparative phylogeography across two trophic levels: the oak gall wasp Andricus kollari and its chalcid parasitoid Megastigmus stigmatizans

Abstract

Insect parasitoids are important components of many terrestrial ecosystems. However, relatively little is known about the mechanisms responsible for structuring their populations. Here we investigate the ability of Megastigmus stigmatizans, an oak gall wasp parasitoid, to track its host Andricus kollari over two different timescales, and examine its current population structure across a divide in host population structure. The divide represents a transition in gall wasp host-plant species and offers the opportunity to examine whether the split, which divides gall wasp populations, manifests itself in the next trophic level. Analysis of mitochondrial haplotype data for parasitoid and host reveals: (i) A similar phylogeographic population structure for both, with Iberian populations more derived with respect to more eastern populations. (ii) It is likely that the host colonized the Iberian refuge earlier than the parasitoid, probably by at least one glacial cycle. (iii) Recent range expansion of central European host populations northwards has resulted in pursuit by parasitoids from the same geographic origin. (iv) In addition, Iberian parasitoid populations have crossed a major divide in host population structure to invade northern Europe. Such human-facilitated escape from natural refugial distributions may have important implications for the composition and structure of northern European gall wasp communities.

How rapidly do invasive birch forest geometrids recruit larval parasitoids? Insights from comparison with a sympatric native geometrid

“…Thus, they may have pursued the invasive geometrids into the study region, but the invaders may also have recruited them locally after the invasion. A phylogeographic study could reveal the origin of the parasitoids attacking O. brumata and A. aurantiaria in our study region (Hayward and Stone 2006;Nicholls et al 2010).…”

No Concordant Phylogeographies of the Rose Gall Wasp Diplolepis rosae (Hymenoptera, Cynipidae) and Two Associated Parasitoids across Europe

“…Co-evolution requires stable communities of interacting species that may undergo parallel diversification [3]. According to the Host-tracking Hypothesis, pairs of interacting species follow the shifts of the distributional ranges of the host species with either concordance in timing (Contemporary Host-tracking Hypothesis) [4], [5] or with a temporal delay (Delayed Host-tracking Hypothesis) [6], [7]. Both forms of the hypothesis predict concordant phylogeographic structures for closely interacting species, such as symbionts, mutualists and host-parasite systems [8]–[10].…”

Comparative Phylogeography in a Specific and Obligate Pollination Antagonism

“…Until now, few studies have investigated the comparative phylogeography of species involved in such specific interactions ( e.g. , the oak gall-wasp and its parasitoids [12], beech and beech parasites [13], aphids and their Rhus hosts [14]) and not any has simultaneously analyzed the large-scale variation in spatial genetic structures of both plants and arthropods involved in specific antagonistic interactions at the continental scale.…”