Cautiously Optimistic

Last October, my lab experienced severe technical difficulties with our butterfly breeding for conservation. This year, we have revamped our efforts considerably. One of the main changes has been to become totally paranoid about lab hygiene. In July, we brought a half dozen silver-bordered fritillary females into the lab and got hundreds of eggs. As of this writing, we have over 400 caterpillars. Pupation has begun- I just counted 43 chrysalides. We are far ahead of where we were last year when disaster struck.

Our new breeding lab. This is about 1/3 of our stock.
Each cup contains 2 silver-bordered fritillary caterpillars

Over the next several weeks, adults will begin emerging from the chrysalides. I will be taking the adults to a site in McHenry County for release. If all goes well, I will also hold back about 50 chrysalides and start an additional generation. We will attempt a release on at least one more site if we have enough offspring (which shouldn’t be a problem). The sites where we will be releasing butterflies are sites where management and ecological restoration have been happening, but where the butterfly is not currently found. The goal here is to establish new populations on each of these sites.

Silver-bordered fritillary larva on host plant (violet).
This is a mature caterpillar that should pupate in the next day or two.

If that weren’t enough, we now also have about 100 swamp metalmark caterpillars in the lab. This species is more delicate, and more difficult to work with. Unlike the silver-bordered fritillary, there is but a single generation per year. The caterpillars that are hatching right now will not become butterflies until next summer. Carrying them over the winter will be a challenge, but will be worth the effort. That species is critically endangered.

Vincent moving newly hatched swamp metalmark caterpillars onto host plant (swamp thistle). He's wearing magnifying glasses because the larvae are so tiny.

Over the rest of the summer, we hope to bring two additional species of butterflies into the lab, with the goal of starting new populations of them, as well.