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!
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.