The butterfly on the left, the Harvester, is Vermont’s only carnivorous butterfly. The butterfly on the right, the Large Blue, is also carnivorous but lives across the pond in Europe.
The Harvester is distinct looking among species with their underwing pattern unlikely to be confused with anything else. Not only are they distinct in their looks, but they’re also monotypic, meaning they are the only species in their genus (Feniseca). (Their closest relatives - delicate Pierrots- live over in southeast Asia!) Their white caterpillars (the carnivorous stage) are white and fuzzy to blend in with their prey – woolly aphids and poplar gall aphids. Your best chance of seeing one is to check the alders along streams for a cluster of Woolly Alder Aphids from mid-May to early September.
The Large Blue like many Blues is an ant-loving myrmecophile. While Blues typically employ all sorts of pheromone tricks to convince ants to carry their caterpillars off to their nests and feed them, the Large Blue instead eats the ant larvae. They have evolved to parasitize one species of red ant, Myrmica sabuleti. Unfortunately, their specialization means they require both their host plant, Wild Thyme, and Myrmica sabuleti, to survive. They are locally extirpated from the Netherlands and the UK and population declines across their range have led to a “Near Threatened” classification by the IUCN.
Photos by
Large Blue by Branislav Tej (iNaturalist)
Harvester by Jeff Cherry (iNaturalist)
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