On 27/5/2003, Ian Paulsen wrote:

> Currently in western WA State we are having an "outbreak" of tent
>caterpillars.

Well, a build up, anyway. I suspect that the real outbreak will come
next year, or maybe the year after. Then the tachinid flies (they lay
their eggs on the caterpillar) and the wilt virus will gain the upper
hand again and the three populations will crash again until the next
time. Note that the widescale use of pesticides against the 'pillars
will retard this progression, keeping tent caterpillar numbers higher
than normal for years. The last really good outbreak in seattle was in
the early-mid 80s. When the 'pillars got to the crawly stage, you
couldn't walk down the street without squashing them.

> I haven't seen any birds eating them and the only birds I
>know that eat caterpillars regularly are cuckoos, but we don't have them
>out here. Does anyone know of or seen birds eating tent caterpillars?

Tent caterpillars are bitter to me, anyway. I handled a few last week,
forgot, and let a finger stray too near my mouth. Bleah. But
according to <http://gardening.wsu.edu/library/inse003/inse003.htm>,
some birds will eat them, and the adult moths are eaten by birds and
bats. Unfortunately, it doesn't say which species:

"Benefits of a caterpillar outbreak can be numerous in a natural
setting. While caterpillars are distasteful to most birds, some birds
feed on them. When alders and other trees are defoliated, the shrubs
and trees below receive increased sunlight, giving some of them a boost
in growth. The eaten leaves pass through the caterpillar's body and
emerge as little pellets which can break down easily, returning
nutrients to the forest floor. Pupae provide nutritious meals for small
mammals, and moths are eaten by birds and bats."

Yellowjackets definitely eat them. Last week I got to watch a yj carve
up a tent caterpillar into steaks and carry them off to the kiddies. A
probable tachinid fly watched too, perhaps disgusted at the waste of a
good larval host. Two warbling vireos and a wilsons completely ignored
them all.
--
Allyn Weaks allyn at tardigrade.net Seattle, WA Sunset zone 5
Pacific NW Native Wildlife Gardening: http://www.tardigrade.org/natives/
"The benefit of even limited monopolies is too doubtful, to be opposed
to that of their general suppression." Thomas Jefferson