The Oregon Zoo has released more than 1,300 Oregon silverspot caterpillars to coastal habitats in a major effort to bolster the threatened b
This is really exciting news from my corner of the world! The Oregon silverspot (Speyeria zerene hippolyta) is a highly endangered subspecies of the zerene fritillary that is only found in northern California and Oregon, and once ranged in extreme southwestern Washington. It is found in coastal meadows, most of which have either been developed, or closed in by forest due to repression of natural and cultural fires.
The silverspot is an excellent example of how insect herbivores tend to have very limited diets. Plants don't want to be eaten, so they produce chemicals that deter and poison herbivores that eat them. It takes a long time and many generations for an animal species to develop a tolerance for these chemicals, so insect herbivores usually only manage to overcome a small number of toxins. Some species, like the silverspot caterpillar, can only eat the leaves of a single species of native plant, and if that plant disappears, so does the insect.
This also illustrates that "save the pollinators" isn't as simple as planting some flowers for adult butterflies and moths. You have to also consider what the caterpillars will eat, and around here planting a bunch if butterfly bush or other non-native species isn't going to cut it. If you aren't feeding the caterpillars, you certainly aren't going to get the butterflies.
Why preserve a single species that is so dependent on one other species? Well, for one thing, every species deserves to exist regardless of whether we consider them to be useful to us or not. Moreover, when we preserve habitat for these isolated species, we also preserve habitat for many others who live in the same place. And we ultimately know very little about the intricate connections species have among each other; when we lose a single species, we have no idea how far-reaching the negative impacts will be across the entire ecosystem.
So while it may seem like a waste of resources to breed and reintroduce the caterpillars of one butterfly species, the potential benefits across the board are more than worth it.



















