TY - GEN A1 - Dennis, Alice B. A1 - Ballesteros, Gabriel I. A1 - Robin, Stéphanie A1 - Schrader, Lukas A1 - Bast, Jens A1 - Berghöfer, Jan A1 - Beukeboom, Leo W. A1 - Belghazi, Maya A1 - Bretaudeau, Anthony A1 - Buellesbach, Jan A1 - Cash, Elizabeth A1 - Colinet, Dominique A1 - Dumas, Zoé A1 - Errbii, Mohammed A1 - Falabella, Patrizia A1 - Gatti, Jean-Luc A1 - Geuverink, Elzemiek A1 - Gibson, Joshua D. A1 - Hertaeg, Corinne A1 - Hartmann, Stefanie A1 - Jacquin-Joly, Emmanuelle A1 - Lammers, Mark A1 - Lavandero, Blas I. A1 - Lindenbaum, Ina A1 - Massardier-Galata, Lauriane A1 - Meslin, Camille A1 - Montagné, Nicolas A1 - Pak, Nina A1 - Poirié, Marylène A1 - Salvia, Rosanna A1 - Smith, Chris R. A1 - Tagu, Denis A1 - Tares, Sophie A1 - Vogel, Heiko A1 - Schwander, Tanja A1 - Simon, Jean-Christophe A1 - Figueroa, Christian C. A1 - Vorburger, Christoph A1 - Legeai, Fabrice A1 - Gadau, Jürgen T1 - Functional insights from the GC-poor genomes of two aphid parasitoids, Aphidius ervi and Lysiphlebus fabarum T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background Parasitoid wasps have fascinating life cycles and play an important role in trophic networks, yet little is known about their genome content and function. Parasitoids that infect aphids are an important group with the potential for biological control. Their success depends on adapting to develop inside aphids and overcoming both host aphid defenses and their protective endosymbionts. Results We present the de novo genome assemblies, detailed annotation, and comparative analysis of two closely related parasitoid wasps that target pest aphids: Aphidius ervi and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae). The genomes are small (139 and 141 Mbp) and the most AT-rich reported thus far for any arthropod (GC content: 25.8 and 23.8%). This nucleotide bias is accompanied by skewed codon usage and is stronger in genes with adult-biased expression. AT-richness may be the consequence of reduced genome size, a near absence of DNA methylation, and energy efficiency. We identify missing desaturase genes, whose absence may underlie mimicry in the cuticular hydrocarbon profile of L. fabarum. We highlight key gene groups including those underlying venom composition, chemosensory perception, and sex determination, as well as potential losses in immune pathway genes. Conclusions These findings are of fundamental interest for insect evolution and biological control applications. They provide a strong foundation for further functional studies into coevolution between parasitoids and their hosts. Both genomes are available at https://bipaa.genouest.org. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 989 KW - Parasitoid wasp KW - Aphid host KW - Aphidius ervi KW - GC content KW - de novo genome assembly KW - DNA methylation loss KW - Chemosensory genes KW - Toll and Imd pathways KW - Venom proteins KW - Lysiphlebus fabarum Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-476129 SN - 1866-8372 IS - 989 ER - TY - GEN A1 - Käch, Heidi A1 - Mathé-Hubert, Hugo A1 - Dennis, Alice B. A1 - Vorburger, Christoph T1 - Rapid evolution of symbiont-­mediated resistance compromises biological control of aphids by parasitoids T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - There is growing interest in biological control as a sustainable and environmentally friendly way to control pest insects. Aphids are among the most detrimental agricultural pests worldwide, and parasitoid wasps are frequently employed for their control. The use of asexual parasitoids may improve the effectiveness of biological control because only females kill hosts and because asexual populations have a higher growth rate than sexuals. However, asexuals may have a reduced capacity to track evolutionary change in their host populations. We used a factorial experiment to compare the ability of sexual and asexual populations of the parasitoid Lysiphlebus fabarum to control caged populations of black bean aphids (Aphis fabae) of high and low clonal diversity. The aphids came from a natural population, and one-­third of the aphid clones harbored Hamiltonella defensa, a heritable bacterial endosymbiont that increases resistance to parasitoids. We followed aphid and parasitoid population dynamics for 3 months but found no evidence that the reproductive mode of parasitoids affected their effectiveness as biocontrol agents, independent of host clonal diversity. Parasitoids failed to control aphids in most cases, because their introduction resulted in strong selection for clones protected by H. defensa. The increasingly resistant aphid populations escaped control by parasitoids, and we even observed parasitoid extinctions in many cages. The rapid evolution of symbiont-­conferred resistance in turn imposed selection on parasitoids. In cages where asexual parasitoids persisted until the end of the experiment, they became dominated by a single genotype able to overcome the protection provided by H. defensa. Thus, there was evidence for parasitoid counteradaptation, but it was generally too slow for parasitoids to regain control over aphid populations. It appears that when pest aphids possess defensive symbionts, the presence of parasitoid genotypes able to overcome symbiont-­conferred resistance is more important for biocontrol success than their reproductive mode. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 620 KW - aphids KW - Aphis fabae KW - biological control KW - defensive symbiosis KW - Hamiltonella defensa KW - Lysiphlebus fabarum KW - parasitoid KW - resistance Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423542 SN - 1866-8372 IS - 620 ER -