Cophylogenetic relationships between Anicetusparasitoids (Hymenoptera: Encyrtidae) and their scale insect hosts (Hemiptera: Coccidae)

Abstract

BackgroundNumerous studies have investigated cospeciation between parasites and their hosts, but there have been few studies concerning parasitoids and insect hosts. The high diversity and host specialization observed in Anicetus species suggest that speciation and adaptive radiation might take place with species diversification in scale insect hosts. Here we examined the evolutionary history of the association between Anicetus species and their scale insect hosts via distance-based and tree-based methods.ResultsA total of 94 Anicetus individuals (nine parasitoid species) and 113 scale insect individuals (seven host species) from 14 provinces in China were collected in the present study. DNA sequence data from a mitochondrial gene (COI) and a nuclear ribosomal gene (28S D2 region) were used to reconstruct the phylogenies of Anicetus species and their hosts. The distance-based analysis showed a significant fit between Anicetus species and their hosts, but tree-based analyses suggested that this significant signal could be observed only when the cost of host-switching was high, indicating the presence of parasite sorting on related host species.ConclusionsThis study, based on extensive rearing of parasitoids and species identification, provides strong evidence for a prevalence of sorting events and high host specificity in the genus Anicetus, offering insights into the diversification process of Anicetus species parasitizing scale insects.

Cophylogenetic relationships betweenDactylogyrus(Monogenea) ectoparasites and endemic cyprinoids of the north‐eastern European peri‐Mediterranean region

“…Eleven models with different event cost schemes were applied, using 500 generations and a population size of 50 as parameters of the genetic algorithm to assess the influence of each type of evolutionary event. The Jane 4.0 default model, TreeMap default model (Charleston, ) and TreeFitter default model (Ronquist, ) were included in our analyses following Deng et al (). Each of these default models assumes that cospeciation has the lowest cost (i.e., is the most common evolutionary event).…”

“…Each of these default models assumes that cospeciation has the lowest cost (i.e., is the most common evolutionary event). Several additional models were included in the cophylogenetic analyses: TreeFitter models adjusted for host switch and codivergence, respectively; a model with equal weights for coevolutionary events following Mendlová et al (); and five models where each event is alternatively extremely penalized (cost of specific event set to 10 and all others to 1, following Deng et al, ). To statistically test whether the global reconstruction cost was significantly lower than expected by chance, 500 randomizations were performed with the use of random parasite trees.…”

“…The Jane 4.0 default model, TreeMap default model (Charleston, 1998) and TreeFitter default model (Ronquist, 1995) were included in our analyses following Deng et al (2013). Each of these default models assumes that cospeciation has the lowest cost (i.e., is the most common evolutionary event).…”

“…and five models where each event is alternatively extremely penalized (cost of specific event set to 10 and all others to 1, following Deng et al, 2013). To statistically test whether the global reconstruction cost was significantly lower than expected by chance, 500 randomizations were performed with the use of random parasite trees.…”

A geography aware reconciliation method to investigate diversification patterns in host/parasite interactions

“…Other nursery pollination/mutualisms such as the interaction between Yucca and their pollinating moths are also good candidates for including geographic constraints into coevolutionary scenarios, as some studies have questioned the respective role of geography and host-plant association in driving the diversification of Yucca moths (Althoff et al 2012). Plant/pollinator systems (Hutchinson et al 2017), parasitoid/host insect associations (Deng et al 2013; Wilson et al 2012), herbivorous insect/plant interactions ( e.g. McLeish et al 2007; Percy et al 2004) and various vertebrate/parasite associations ( e.g.…”