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Vansant, H.

Publications and source records attributed to Vansant, H..

2 recordsLinked to original sources

Genome of the parasitoid wasp Dinocampus coccinellae reveals extensive duplications, accelerated evolution, and independent origins of thelytokous parthenogeny and solitary behavior

Dinocampus coccinellae (Hymenoptera: Braconidae) is a generalist parasitoid wasp that parasitizes >50 species of predatory lady beetles (Coleoptera: Coccinellidae), with thelytokous parthenogeny as its primary mode of reproduction. Here we present the first high quality genome of D. coccinellae using a combination of short and long read sequencing technologies, followed by assembly and scaffolding of chromosomal segments using Chicago+ HiC technologies. We also present a first-pass ab initio genome annotation, and resolve timings of divergence and evolution of (1) solitary behavior vs eusociality, (2) arrhenotokous vs thelytokous parthenogenesis, and (3) rates of gene loss and gain among Hymenopteran lineages. Our study finds (1) at least two independent origins of eusociality and solitary behavior among Hymenoptera, (2) two independent origins of thelytokous parthenogenesis from ancestral arrhenotoky, and (3) accelerated rates of gene duplications, loss, and gain along the lineages leading to D. coccinellae. Our work both affirms the ancient divergence of Braconid wasps from ancestral Hymenopterans and accelerated rates of evolution in response to adaptations to novel hosts, including polyDNA viral co-evolution.

genomics↗

Coccinellid host morphology dictates morphological diversity of the parasitoid wasp Dinocampus coccinellae

Pararsitoid-host interactions involving host species that are newly introduced into the range of a generalist parasitoid provide systems that can be examined for phenotypic plasticity and evolutionary changes in parasitoid-host dynamics. The solitary Braconid parasitoid wasp, Dinocampus coccinellae, has a cosmopolitan distribution and parasitizes approximately 50 species of predatory lady beetles (ladybirds) in the family Coccinellidae. In this study we quantified the effect of six (4 native North American and 2 non-native North American) host species on the morphometrics of D. coccinellae. Adult lady beetles were collected from 13 locations in the United States and reared in the laboratory until D.coccinellae exited from their adult beetle hosts. Eighty-nine individual D. coccinellae females and their associated host were weighed and morphometric measurements were taken. The smallest lady beetle host Hippodamia parenthesis produced the smallest adult wasps; the largest host species, Coccinella septempunctata, produced the largest female wasps. A directional cline in morphology of wasps and their coccinellid hosts was also observed in a dry-weight regression (R2 = 0.4066, p-value < 0.0001). Two underlying mechanisms may explain the results of our study: (1) morphometric variation in D. coccinellae is governed by phenotypic plasticity with the size of the emerging offspring contingent on the size of the coccinellid host, and/or (2) that morphometric variation in D. coccinellae is governed by genomic adaptation to coccinellid host populations.

evolutionary biology↗