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Science AMA Series: We’re Drs. Kelly Weinersmith, Andrew Forbes, and Scott Egan! We just released a paper documenting a new case of parasite manipulation of host behavior. AMA!
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Thanks for your awesome questions, everyone! We’re going to start winding things down now. We had a ton of fun! We’re scientists from Rice University and University of Iowa, and we recently described a new example of parasite manipulation of host phenotype, in which a previously undescribed parasitoid (Euderus set) manipulates the behavior of its cynipid gall wasp host (Bassettia pallida), which is itself a parasite of sand live oaks. The host, B. pallida, induces the formation of a crypt in sand live oaks, and undergoes development in these crypts. Upon becoming an adult, B. pallida excavate an emergence hole and emerge from the crypt. When B. pallida are infected by E. set, they excavate an incomplete emergence hole, block the hole with their head capsule, and then die. While many examples of apparent parasite manipulation of host behavior exist, in only a subset of these systems do we have strong evidence that the host’s infected behavioral phenotype actually increases the fitness of the parasite. We experimentally demonstrated that this modified behavior benefits the parasitoid, as E. set that have to excavate their own emergence hole are about 3 times more likely to die trapped in the crypt relative to parasitoids that only need to emerge through their host’s head capsule. Additionally, this system represents a novel case of hypermanipulation – where a parasite manipulates the phenotype of a host that is itself a parasitic manipulator. The parasitoid is also new to science! The parasitoid fell in the genus Euderus, and we decided to name the species Euderus set, after the Egyptian god Set. Set was the god of evil and chaos, and had control over evil animals like serpents. We thought this was fitting since E. set is the parasite of a parasite (which mirrors an evil being controlling another evil being). Additionally, E. set kills its host in a crypt, consumes the host’s internal organs, and then scatters the exoskeleton of its host around the crypt. The Egyptian God Set trapped Osiris (his brother) in a crypt, and later chopped his body into small pieces. We gave the parasitoid the common name the crypt-keeper wasp. We’re definitely biased, but we think the parasitoid is beautiful! The paper in which we describe the new parasitoid species and the paper where we document the manipulation are both Open Access. Here is artwork from the amazing Boulet that describes the system. We’re happy to answer questions about gall-forming insects, identifying new species, and parasite manipulation of host behavior. We’re excited to talk to you! We’ll be back at 12:30 EST to answer your questions. Ask us anything! Follow us on Twitter: Kelly Weinersmith: @FuSchmu Andrew Forbes: @Lord_Forbington *Edited to include link to our paper, link to Boulet’s artwork, and our twitter account info.