Extension's Sustainable Tourism Blog « http://tourism.oregonstate.edu

Bees sip honey from flowers and hum their thanks when they leave.
The gaudy butterfly is sure that the flowers owe thanks to him.
Rabindranath Tagore

The Oregon coast is very lucky to have a native butterfly species that is both colorful and spectacular.

The Oregon Swallowtail is part of a larger Papilionidae family that includes some of the largest and most beautifully colored butterflies in North America. North America has 40 species.

Territory

The Oregon swallowtail lives only in Oregon, Washington, Idaho, and south-central British Columbia. Swallowtail species can be found in the Arctic Circle south into Mexico. Most sightings in Oregon are along the mainstems and immediate tributaries of the Columbia, Deschutes and Snake Rivers.

There are over 550 butterfly species in this family. Most reside in tropic and subtropic regions. The Oregon Swallowtail may have originated there.

Food

Adults feed on wildflower nectar from thistles, balsamroot, phlox, daisies, asters, rabbitbrush, penstemon, milkweed, and dogbane. The larvae (juveniles) feed on tarragon sagebrush (also called wild tarragon or dragon wormwood, Artemisia dracunculus).

Swallowtail butterfly caterpillars feed on a wide range of plant families, and often depend on one of five families: Aristolochiaceae, Annonaceae, Lauraceae, Umbelliferae (Apiaceae) and Rutaceae. These plant families include toxic plants. Once eaten, the toxin makes both the caterpillar and butterfly also toxic which helps protects them from predators.

Predation

Oregon Swallowtails have wingspans up to 4-inches that sport a bright yellow with black-lined pattern and a ‘tail’ that extends off the back wing. The yellow wing markings of the Oregon swallowtail are brighter than the common swallowtail.

The tail is not required for flight, and may be sacrificed to escape predation. The hope is that the bird may ‘swallow the tail’ rather than a more critical body part and allow the butterfly to survive.

Several Swallowtails can also change their behaviors to help reduce predation. They will imitate the behaviors of other distasteful species, and several studies show females imitating males as a way to reduce predation.

Predators can include birds, wasps, spiders, and preying mantis, skinks, skunks and human collectors.

When to look

Look for Oregon Swallowtail butterflies in flight between April and September. Those seen early in the year are generally lighter in color than those seen later and blend well with the color of early plants.

Swallowtails are wary and strong fliers. This butterfly was selected as Oregon’s official insect on July 16, 1979, not only because it is a native but also because it has ‘Oregon’ in is common and scientific names. Oregon Swallowtail butterflies are a wonderful aesthetic gift.

REFERENCES:
–Oregon Dept. of Fish & Wildlife, Oregon Swallowtail Factsheet (https://www.dfw.state.or.us/conservationstrategy/docs/Swallowtail_factsheet.pdf)
–Butterfly Identification, Oregon Swallowtail (https://www.butterflyidentification.com/oregon-swallowtai.htm)
–EReference desk (https://www.ereferencedesk.com/resources/state-insect/oregon.html)
Wikipedia, Papilio machaon oregonius (https://en.wikipedia.org/wiki/Papilio_machaon_oregonius)

Is it possible to say something good about Gorse?

Maybe. Depends on if you have ever tried to get rid of it or not.

Some consider Gorse as a pretty, fragrant shrub. Others class it as something akin to devil spawn.

Gorse maintains a love-hate reputation not only with humans but other plants. In both cases, it has earned this reputation well.

Is anything good?

Gorse was commonly used in several ways including as a:
–Food source (the flowers are edible). Plant can be used as livestock feed as it is high in protein. Pollen from the various varies help pollinators, such as bees.
–Product creation such as soap making, yellow dye, cleaning tools
–Traditional Medicines (listed as one of 38 plants in the Bach’s Flower Remedies.

Lots o’ Bad

Gorse has earned a dubious reputation in several ways and is now on several invasive and noxious lists for States and countries. Bandon is no stranger to this plant that arrived over 100 years ago thanks to ‘Lord’ George Bennett, an Irish immigrant. In Ireland, the plant had many uses and natural biological controls generally not present here.

Bandon is ‘ground zero’ for gorse removal and fire risk reduction. The rumor is that gorse helped fuel the Bandon Fire of 1936 that burned down most of the town. A Gorse Action Group in Bandon is working on the problem (see What’s the Deal with Gorse? (https://sea-edu.org/2019/12/17/whats-the-deal-with-gorse/). Then again, dried gorse was used as kindling and a fire fuel for bread making ovens.

More Hate than Love

There is a lot more hate than love now-a-days, and fortunately controls that can help manage this noxious weed. Here is a quick comparison:

A Small Gorse Spider Mite Experiment

Mites control gorse through extensive feeding pressure. The mites will through feeding kill shoots, reduce plant growth and overall plant biomass, and abort the production of flowers. It can take a long time for these mites to control the gorse. What if we could help this along?

This is our little experiment:
Year 1: We took a few, small cuttings from mite-infected plants and threw them on some bushes. Result: Mite spread slow but evident, and did not persist on some bushes.
Year 2: We took larger cuttings off of several bushes that exhibited mite infestation. Placed several 6-inch sprigs on approximately 12 other bushes with light or relatively no infestation. Result: All bushes infected; most showed some stress.
Year 3: Mechanical removal employed on several large, bushes. Result? Can’t wait to plant the area. More mechanical and hand removal is in progress. It will be interesting to look back next year and see the results. I think I also spotted a Gorse soft shoot moth on my shovel handle. There is hope.

OTHER REFERENCES:
–Wikipedia, Ulex (https://en.wikipedia.org/wiki/Ulex_europaeus)
–Tasty Natives, Ulex europaeus (https://www.greenlab.org/tastynatives/2018/11/01/gorse/
—6 organic ways to get rid of gorse (https://thisnzlife.co.nz/5-organic-ways-get-rid-gorse/) (Note: link does say 5 rather than 6 as in title, error in link naming)
—What are the effects of gorse on the ecosystem? (http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/a-z-of-weeds/gorse)
–University of Washington, 66-8633 Gorse Soil Effects (https://portal.nifa.usda.gov/web/crisprojectpages/0213036-66-8633-gorse-soil-effects.html)
—Victorian Gorse Taskforce (https://www.vicgorsetaskforce.com.au/biological-control/)

And I’d like to give my love to everybody, and
let them know that the grass may look greener on the other side,
but believe me, it’s just as hard to cut.
Little Richard

Beachgrass in the sunset, royalty free, Unsplash

As environmental mis-steps go, planting European Beachgrass at Golden Gate Park, San Francisco, in the late 1800s probably seemed like a great idea. This grass successfully stabilized dunes in Europe and North Africa and many agencies planted thousands of acres, much of it in Oregon.

It seemed like such a good idea

European Beachgrass forms stiff, hardy clumps of grass that can reach nearly four feet tall. A strong rhizome mat holds clumps erect and facilitate fast colonization across an area. One small clump can produce 100 new shoots annually.

This plant provided a faster way to stabilize sand dunes, had few pests and predators, and grows very densely. The grass changes the shape of a dune and overall native ecology by displacing plants and animals by creating higher, steeper curve on the ocean side of a dune. This decreases sand flow to interior dunes impacting the long-term development of the whole coastal ecosystem.

Beachgrass on dune, royalty free Unsplash

One tough grass

Not only does European Beachgrass grow fast and dense, but it will tolerate a number of adverse conditions. For instance, the plant will survive for extended periods of time when buried by sea water and/or sand. In such a disturbance, rhizome pieces will break off. These pieces begin growing in new sites.

It will also grow in a variety of conditions both in pH, mineral or chemical issues, temperatures, and as a perennial live many years. A fungus that grows on the grass, may also make dunes less fertile and thus less likely to support other plants.

The impact?

Beachgrass is one of the most pervasive exotic plant species threatening the West Coast. It is everywhere and not only creating problems for plants but animals such as the endangered western snowy plover by increasing predator cover.

This noxious weed grows from California north along the Pacific coast into British Columbia. This grass was also planted in New Zealand and Western Australia and is considered noxious.

Is it controllable?

Maybe. Interest in controlling began about 1980. Finding a method that is effective, inexpensive, minimally invasive to other native species, flexible enough to use on steep slopes, and acceptable to a wide variety of land owner/managers is a tough challenge.

Several research projects have been underway for years looking at various removal techniques such as manual, mechanical, chemical, and fire alternatives. Other methods are still being sought.

REFERENCES:
–US Dept. of Agriculture (https://plants.usda.gov/core/profile?symbol=AMAR4)
–California Invasive Plant Council (https://www.cal-ipc.org/plants/paf/ammophila-arenaria-plant-assessment-form/, https://www.cal-ipc.org/wp-content/uploads/2019/01/Cal_IPC_Symposium_2018_Monique_Silva-Crossman_Effects-_of_Ammophila_arenaria_removal.pdf, and https://www.cal-ipc.org/wp-content/uploads/2017/12/1997_symposium_proceedings1934.pdf)
–Wikipedia, Ammophila Arenaria (https://en.wikipedia.org/wiki/Ammophila_arenaria)
–AZ Quotes (https://www.azquotes.com/quotes/topics/greener-on-the-other-side.html)

Extension's Sustainable Tourism Blog

http://tourism.oregonstate.edu

Oregon Swallowtail (Papilio oregonius)