Ah, I just realized the link I sent didn't even have a picture. I figured there is only one bird poop caterpillar but I guess not. Here is the first one I suggested (Giant Swallowtail): http://www.enature.com/fieldguide/showSpecies_LI.asp?imageID=22479 But apparently the Western Tiger Swallowtail also has a bird poop caterpillar and it feeds on Alder: http://www.geocities.com/RainForest/4148/pageeleven.html "The caterpillar has two distinct forms at different stages. While the young caterpillar is brown and white, resembling bird droppings (an ingenious protection against being eaten by birds!) - the mature caterpillar, growing to about 2 inches, is green with a swollen front end, large eyespots on the head, and a black and white band between the 3rd and 4th segments. Using silk, the caterpillar curls leaves over its body and rests and feeds under a protective canopy." I couldn't find any caterpillar pictures for this species. Arlene Mikelsons wrote: > The particular caterpillars I am finding now are quite abundant on > young alders or maybe even on old alders but too high for me to see. > At any rate, they are whitish and look almost powdery. The biggest I > have seen is about 1/2 inch long. I am keeping a couple to see if I > can maintain them until they become whatever they will become. If I > can get some time from the demands of the veggy garden, blackberry > picking and making boat covers for my husband, I will attempt to get a > good photograph. > > Thanks again for the information. > > Arlene M. > > > Paul Furman wrote: > from the pnw-spineless bug list... > > Someone asked about the 'Bird Dropping Caterpillar' > http://www.desertmuseum.org/books/nhsd_butterflies.html > "Giant Swallowtail (Papilio cresphontes, also called Heraclides > cresphantes), ), a brown and yellow species commonly encountered in > urban areas. Its larvae, which feed mostly on the leaves of citrus, > look much like fresh bird droppings. If the larvae are touched or > disturbed, an unpleasant-smelling, y-shaped orange organ called an > osmeterium, is everted from just behind the head. This device and the > cryptic appearance are adaptations to avoid predators and perhaps > parasites." > > I've noticed this same osmeterium thing on our pipevine Swallowtails > when they are poked: > > <http://www.edgehill.net/2003-08-09-pipevine-caterpillar> > -- Paul Furman http://www.edgehill.net san francisco native plants (415) 722-6037
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