How do migration-driven changes in resource allocation and pace-of-life contribute to heterogeneity in immune function in a butterfly model species?

The monarch butterfly (Danaus plexippus) undergoes spectacular long-distance migrations in parts of its worldwide range, and is also affected by debilitating parasites, including the protozoan Ophryocystis elektroscirrha (OE).  Monarch migration is known to cause dramatic shifts in life history and resource allocation between breeding and migratory generations, presenting a unique opportunity to examine how immune defense trades offs against other life history functions both in the field and laboratory. Monarchs in eastern North America undertake one of the longest migrations known to any insect, traveling from as far north as Canada to Central Mexico each fall. Monarchs born in the spring and summer reproduce rapidly and adults are short lived, whereas monarchs born in late summer and fall enter a state of reproductive diapause (delayed reproduction) and migrate, leading to over an eight month lifespan.  Monarchs inhabiting tropical and subtropical locations, by comparison, breed year-round without entering diapause and do not migrate.

My research investigates the consequences of long-distance migration for immune defense.  I will ask how variation in immunity depends on (i) underlying resource availability,  (ii) differences between migratory and non-migratory generations within populations  and (iII) evolutionary differences among distinct populations that differ in their migratory behaviors.

I will use a combination of field studies, lab experiments, and potentially dynamic models to investigate these questions.