Interesting Gray Furcula Moth Caterpillar Find

Today down at Cerrito Creek near El Cerrito Plaza shopping center, we discovered an interesting caterpillar we had never seen before and have identified it as the larvae of the Gray Furcula Moth (Furcula cinereoides​).

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Cerrito Creek begins in the Berkeley Hills, serving as part of the border between Alameda (Albany) and Contra Costa (El Cerrito) County and ends in the San Francisco Bay. After suffering from urbanization efforts in the 1900's, a lot of restoration projects have been made on the creek and it looks pretty nice today, consisting mostly of native trees and shrubs with a decent amount of wildlife still around.

At least down at the El Cerrito Plaza, the creek is surrounded by many riparian plants such as willow, cottonwood, live oak, sycamore, and alder, as well as ceanothus. We had decided to visit mainly because a lot of these trees are listed as food plants of the Western Tiger Swallowtail (Papilio rutulus). We also wanted to check out the quality of the ceanothus leaves for our Ceanothus Moth caterpillars (Hyalophora euryalus) but in the end neither endeavor was successful.  

However, when we were searching a willow tree (Salix spp.), we discovered an odd looking caterpillar under a leaf. The caterpillar was very small, probably a second or third instar and it was currently in apolysis. Immediately we identified it as some species of prominent because of its characteristic forked tail, but were unsure of the exact species. After we got home we identified it as a Gray Furcula Moth caterpillar (Furcula cinereoides). We also realized that the caterpillar's tails were supposed to be of equal size and length but that was not true of our caterpillar. It is hard to tell, but it appears that one of the tails had been broken at the tip. Regardless, we are interested to see what becomes of this caterpillar and how big it will grow since we have never had one in the past and hopefully we have identified it correctly! 

- Brian