The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps.

Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the "Angiosperm Terrestrial Revolution". Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3-180.5 Ma) and a crown age of 162.2 Ma (153.9-169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history

Parasitoid hymenoptera hosts specialisation and defensive mechanisms of their host species

Parasitoids (Hymonoptera: "Parasitica") are very large group of insects. Their diversity is also enormous in various morphological adaptations and hosts specialisations. The bachelor thesis summarize particular types of host specialisations and compare generalits and specialists from taxonomical, ecological, evolutionary and geographical point of view. The thesis include summary of theories concerning host-defence adaptations against parasitoids (i.e. morphological adaptations, space-time adaptations) as well. Key words: Apocrita, specialist, generalist, defensive mechanism, evolutuio

Evolution of parasitic Hymenoptera hosts specialisation of the genus Torymus

The genus Torymus (Chalcidoidea: Torymidae) has very diversified parasitic strategies and adaptations to its hosts. Its larvae are ectoparasitoids and attack mostly larvae of various gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). However, few species prefer also other insect groups as a host or are even phytophagous. Many hypotheses concerning evolution of insect host associations were published, but have not been satisfactorily tested using parasitic insects as a model. In this thesis I studied coevolution of the genus Torymus and its hosts. The main questions are what kind of host shifts occurred during the evolution of host strategies and whether sister species of parasitoids are specific to the related hosts/or nonrelated hosts living in the same type of habitat. I also studied changes at morphological adaptations to its hosts. To test critically these hypotheses, I constructed phylogenetic tree of selected Torymus species based on 5 genes and compared their host association within and between clades of Torymus. Key words: Torymus, Chalcidoide, parasitoid, phylogeny, host specialisatio

The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps

Raw paired reads were uploaded as NCBI Sequence Read Archives (PRJNA884376 for AHE and PRJNA1017994 for UCEs).We dedicate this work to the memory of our dear friend and colleague John LaSalle, specialist of Eulophidae, who was an enthusiastic member of this project.International audienceChalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the “Angiosperm Terrestrial Revolution”. Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3–180.5 Ma) and a crown age of 162.2 Ma (153.9–169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history