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The boom-and-bust life of defoliating insects

Amy Grotta's Tree Topics - Fri, 06/20/2014 - 12:35pm

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

It is shaping up to be another exciting year in forest health here in northwest Oregon. Fortunately, neither of the two defoliating insects currently on the scene are serious threats to forest or human health, but they are certainly causing a stir.

Right now, Columbia County is in the midst of the largest documented western tent caterpillar outbreak that Oregon has seen in two decades, according to the Oregon Department of Forestry. I first noticed a few tent caterpillar clusters on one site in the area two years ago. Last summer, our Extension office received many calls as the caterpillar population built up.  Aerial surveys done a few weeks ago show that at least 13,000 acres are affected in the county this year.

Map and aerial view showing extent of western tent caterpillar defoliation, early June. Affected areas are brown in the photo. Source: Oregon Department of Forestry

The caterpillars are everywhere in the most heavily affected areas. It’s impossible to move without stepping on them, and looking up through a stand of alder, it looks like early spring as there are no leaves left on the trees.

Western tent caterpillars infected by a virus hang in an upside-down V. Photo: Amy Grotta

When the population gets to this level, natural parasites and diseases set in. Upon closer inspection, one can see that some of the caterpillars are hanging limply from their midsections: a symptom that these diseases are beginning to take hold, signaling the end of the boom years and the beginning of the bust.

Other defoliating insects follow similar boom-and-bust cycles, in concert with their respective natural enemies. The western oak looper, which made its appearance in 2012 and 2013 in the mid-Willamette Valley, and the pine butterfly, which affected over 250,000 acres in eastern Oregon in 2011-12, are two examples. Reports are beginning to trickle in that the oak looper is still on the scene in places this year, but the pine butterfly outbreak is over. In 2013, researchers in eastern Oregon observed abundant “boom” populations of two insects that are predators of the pine butterfly larvae.

In Columbia County, 2014 will go down in the books as another “year of the caterpillar”. Longtime residents can recall the years marked by previous outbreaks of these insects, just as with big floods and wind storms. One Rainier old-timer recalls another big tent caterpillar year in the 1950’s.

The interactions between these forest insects and their natural enemies are an example of how biodiversity at the smallest scale within a forest system leads to patterns that we can observe. Sadly, in our coastal ecosystem, a pathogen is killing off sea stars in unprecedented numbers. It remains to be seen whether the sea stars will be able to rebound, or if they will be busted for good.

Categories: OSU Extension Blogs

Food Science Camp 2013 and Erik Fooladi

Bringing Food Chemistry to Life - Fri, 07/19/2013 - 1:44pm

We participate in the Oregon State U Food Science Camp for middle school students.

Part of the STEM [science technology engineering math] Academies@OSU Camps.

We teach about bread fermentations, yeast converting sugars to CO2 and ethanol, lactobacillus converting sugar to lactic and acetic acids, how the gluten in wheat can form films to trap the gas and  allow the dough to rise. On the way we teach about flour composition, bread ingredients and their chemical functionalities, hydration, the relationships between enzymes and substrates [amylases on starch to produce maltose for the fermentation organisms]; gluten development, the gas laws and CO2′s declining solubility in the aqueous phase during baking which expands the gas bubbles and leads to the oven spring at the beginning of baking; and the effect of pH on Maillard browning using soft pretzels that they get to shape themselves..

All this is illustrated by hands on [in] activities: they experience the hydration and the increasing cohesiveness of the dough as they mix it with their own hands, they see their own hand mixed dough taken through to well-risen bread. They get to experience dough/gluten development in a different context with the pasta extruder, and more and more.

A great way to introduce kids to the relevance of science to their day to day lives: in our case chemistry physics biochemistry and biology in cereal food processing.

We were also fortunate to have Erik Fooladi from Volda University College in Norway to observe the fun: http://www.fooducation.org/

If you have not read his blog and you like what we do here: you should!

 

endless pasta

 

Categories: OSU Extension Blogs

Good Cheese, Bad Cheese

Bringing Food Chemistry to Life - Wed, 07/10/2013 - 1:25pm

pH, colloidal calcium phosphate, aging, proteolysis, emulsification or its loss and their interactions lead to optimum melting qualities for cheeses. A module in this year’s food systems chemistry class.

This module was informed by this beautiful article “The beauty of milk at high magnification“ by Miloslav Kalab, which is available on the Royal Microscopical Society website.

http://www.rms.org.uk/Resources/Royal%20Microscopical%20Society/infocus/Images/TheBeautyOfMilk.pdf

Of course accompanied by real sourdough wholegrain bread baked in out own research bakery.

Inspired by…

“The Science of a Grilled Cheese Sandwich.”

by: Jennifer Kimmel

in: The Kitchen as Laboratory: Reflections on the Science of Food and Cooking

Edited by Cesar Vega, Job Ubbink, and Erik van der Linden

 

Categories: OSU Extension Blogs

February 2011- Nutrition Education Volunteers taking “vacation”

Family Food Educators of Central Oregon - Tue, 02/01/2011 - 9:24am

I’m back from maternity leave and getting resettled into some new responsibilities.  We had a staff member leave us, so Glenda and I are having to pick up the work load until we find someone new, or our responsibilites change.  Being a new mom is lots of work too, so I’ve gone part time (24 hours aweek) but am still trying to get everything done… that being said, we’ve decided to put our nutrition education volunteering on hold, until I have a managable workload.

We look forward to being able to start things back up in the summer or fall of 2011.  Thanks so much and since a few of you have been asking, here’s a photo of our boy.  He is 5 months old today!

Bundled out in the cold!

Categories: OSU Extension Blogs