Dragonfly Swarms, Mother Earth News, and Heritage Harvest Festival

Dragonfly photo courtesy Staunton News Leader

Swarms of dragonflies are popping up  in Virginia

Leanna Smith, in the Staunton News Leader reported that meteorologists in Ohio had spotted something unexpected on the radar on September 10 — a swarm of migrating dragonflies. The radar maps are impressive! The Common Green Darner dragonflies (Anax junius) were reported swarming in Maryland (Sep 11 evening), New Jersey (Sep 12 nighttime) and Virginia (Sep 11 and Sep 12 morning).

She reported that it is common for dragonflies, especially green darner dragonflies, to migrate south in the fall to find warmer weather, but the swarming is unusual. Ohio State University Entomology Professor Norman Johnson spoke to CNN and said that weather conditions can cause the traveling insects to swarm. In 2018, the Washington Post reported that the migration of green darner is typically unremarkable because the insects rarely travel in packs. Although much is still unknown about the migration of dragonflies, we do know that they are very sensitive to temperature. “Climate warming could really disrupt the presence of this migration,” Colin Studds, an animal ecologist at the University of Maryland Baltimore County, told the Post.

It is fairly common for radar to pick up biological movement, especially around sunrise and sunset when warmer air above us can bend the radar beam toward lower elevations where the movement is occurring, according to meteorologist Chris Michaels.

On September 10, the National Weather Service of Cleveland, Ohio tweeted about the new development.

Clouds of dragonflies.
Photo NWS Cleveland @NWSCLE

Ohio State University entomologist Norman Johnson said the dragonflies are likely Green Darners, which migrate south in the fall. “The insects don’t usually travel in flocks,” he told CNN, “but local weather conditions can cause them to bunch up.” “The big swarms have been recorded a lot over the years, but they’re not regular,” Johnson said.

Details of dragonfly migration are still unclear; researchers have found the winged creatures travel an average of 8 miles per day, but can fly as far as 86 miles.

For up to the minute sightings, see the Migratory Dragonfly Partnership Search page

TOWARD THE UNKNOWN  A common green darner can migrate hundreds of kilometers each year. A new study reveals details of the insects’ annual migration for the first time. Photo Mark Chappell

Susan Milius in Science News reports that Green Darner dragonflies migrate a bit like monarch butterflies, with each annual migratory loop taking multiple generations to complete.

Ecologist Michael Hallworth and colleagues wrote the migration of the common green darner, described December 19, 2018 in Biology Letters, using data on forms of hydrogen in the insects’ wings, plus records of first arrivals spotted by citizen scientists. Citation https://doi.org/10.6084/m9.figshare.c.4320911.v2

“A first generation of insects emerges in the southern United States, Mexico and the Caribbean from about February to May and migrates north. Some of those Green Darners reach New England and the upper Midwest as early as March, says Hallworth, of the Smithsonian Migratory Bird Center headquartered in Washington, DC.

Those spring migrant darners lay eggs in ponds and other quiet waters in the north and eventually die in the region. This second generation migrates south from about July until late October, though they have never seen where they’re heading. Some of these darners fly south in the same year their parents arrived and some the next year, after overwintering as nymphs.

A third generation emerges around November and lives entirely in the south during winter. It’s their offspring that start the cycle again by swarming northward as temperatures warm in the spring. With a wingspan as wide as a hand, they devote their whole lives to flying hundreds of kilometers to repeat a journey their great-grandparents made.

Tracking devices that let researchers record animals’ movements for more than a week or two haven’t been miniaturized enough to help. The smallest still weigh about 0.3 grams, which would just about double a darner’s weight, Hallworth says. So researchers turned to chemical clues in darner tissues. Conservation biologist and study coauthor Kent McFarland succeeded at the delicate diplomacy of persuading museums to break off a pinhead-sized wing tip fragment from specimens spanning 140 years.

Researchers checked 800 museum and live-caught specimens for the proportion of a rare heavy form of hydrogen that occurs naturally. Dragonfly wings pick up their particular mix of hydrogen forms from the water where the aquatic youngsters grow up. Scientists have noticed that a form called hydrogen-2 grows rarer along a gradient from south to north in North America. Looking at a particular wing in the analysis, “I can’t give you a zip code” for a darner, Hallworth says. But he can tell the native southerners from Yankees.

An adult darner, regardless of where it was born, is “a green piece of lightning,” says McFarland, of the Vermont Center for Ecostudies in White River Junction. Darners maneuver fast enough to snap insect prey out of the air around ponds across North America. The front of an adult’s large head is “all eye,” he says, and trying to catch samples for the study was “like hitting a knuckleball.”

Although the darners’ north-south migration story is similar to that of monarch butterflies (Danaus plexippus), there are differences, says evolutionary biologist Hugh Dingle of the University of California, Davis, who has long studied Monarchs, which move northward in the spring in successive generations, instead of one generation sweeping all the way north.

Also, Dingle says, pockets of monarchs can buck the overall scheme. Research suggests that some of the monarchs in the upper Midwest do a whole round trip migration in a single generation. As researchers discover more details about green darners, he predicts, the current basic migration scheme will turn out to have its quirky exceptions, too.”

MASS MIGRATION

At least three generations make up the annual migration of common green darner dragonflies. The first generation emerges in the southern United States, Mexico and the Caribbean starting around February and flies north. There, those insects lay eggs and die, giving rise to second generation that migrates south until late October. (Some in that second generation don’t fly south until the next year, after overwintering as nymphs.) A third generation, hatched in the south, overwinters there before laying eggs that will start the entire process over again. These maps show the emergence origins of adult insects (gray is zero; red is many) captured at sampling locations (black dots).

Diagram by Matthew Dodder, M.T. Hallworth et al/Biology Letters 2018

Geek.com reports that this isn’t the first insect invasion of 2019. In June, the National Weather Service’s radar in San Diego picked up a giant crush of ladybugs about 80 miles across in each direction, over southern California. On June 27, residents of northeastern Ohio found themselves dealing with invasive mayflies, which covered cars, houses, and lampposts across Cleveland, Sandusky, and other areas.

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Mother Earth News Fair

I had a great time at the Mother Earth News Fair at Seven Springs, Pennsylvania. My first workshop, Lettuce Year Round, was on Friday lunchtime and attendees were still arriving. For those who wanted to hear all about it, but missed it, here is the slideshow:

And here is the extended version of Hoophouse Cool Season Crops. It has a lot of bonus material compared to the short workshop I gave last weekend.

Note that all the offers of pdfs of my books to download are scams and nothing to do with me! I cannot stop people posting them. It’s almost enough to stop me posting my slideshows, but I know people appreciate another chance to see the slides.

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Heritage Harvest Festival

This coming weekend, Saturday September 21, I’ll be presenting Winter Gardening: No Tech to High Tech with Ira Wallace at the Heritage Harvest Festival at Monticello in Charlottesville, VA. Ira will talk about outdoor winter gardening, and I’ll talk about hoophouse growing (which isn’t really that high tech!) It’s Saturday, Sept. 21 at 10:30am in the Heritage Tent. Here’s the LINK. The workshop is for gardeners to learn tips on growing cold-hardy vegetables (and not just kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses.

Read more about the Heritage Harvest Festival here

Buy tickets in advance here

Weeding rowcovered spinach in winter.
Photo Wren Vile

Mother Earth News Fair PA, Heritage Harvest Festival, Ginger Field Day, Future Harvest CASA Beginning Farmer Training

I’ve updated my Events Page, so check there for events I hope to be speaking at between now and the end of March.

Coming right up:

September 14-16, 2018 Mother Earth News Fair, Seven Springs, PA

I’m presenting two workshops:

Fall and Winter Hoophouses Friday 5-6 pm at the Heirloom Gardener Stage

How to grow varied and plentiful winter greens for cooking and salads; turnips, radishes and scallions. How to get continuous harvests and maximize use of this valuable space, including transplanting indoors from outdoors in the fall. The workshop includes tips to help minimize unhealthy levels of nitrates in cold weather with short days. Late winter uses can include growing bare-root transplants for planting outdoors in spring.

Lettuce Year Round (NEW!) Sunday 2-3 pm at the Heirloom Gardener Stage

This presentation includes techniques to extend the lettuce season using rowcover, coldframes and hoophouses to provide lettuce harvests in every month of the year. The workshop will include a look at varieties for spring, summer, fall and winter. We will consider the pros and cons of head lettuce, leaf lettuce, baby lettuce mix and the newer multileaf types. Information will also be provided on scheduling and growing conditions, including how to persuade lettuce to germinate when it’s too hot.

Handouts

Book-signing

Demonstrations of tomato string-weaving and use of wigglewire to fasten hoophouse plastic to frames, at the New Society Publishers booth. Fri 12.30-1.30pm, 3.30-4.30pm; Sat 11.30-12.30, 5-6 pm; Sun 9.30-10 am, 11.30 am-12.30 pm.

Wigglewire is reusable every time you change the plastic on your hoophouse.
Photo Wren Vile

September 21-22 Heritage Harvest Festival, Monticello, near Charlottesville, Virginia

Premium Workshop on Friday Sept 21, 3-4 pm Classroom 7

Feeding the Soil

In this workshop I will introduce ways to grow and maintain healthy soils: how to develop a permanent crop rotation in seven steps, and why your soil will benefit from this; how to choose appropriate cover crops; how to make compost and how to benefit from using organic mulches to feed the soil. Handouts.

Book-signing Friday 4.15 – 4.45 pm

Heritage Harvest Festival

I’m sadly not attending the Virginia State University Ginger and Turmeric Field Day, but I recommend it!

GINGER/TURMERIC FIELD DAY

OCTOBER 18, 2018

REGISTRATION WILL OPEN SOON AT EXT.VSU.EDU

  • Thursday, October 18, 2018, 8:00 AM 4:00 PM
  • VSU Randolph Farm 4415 River Road Petersburg, VA (map)
  • Ginger and turmeric have been used widely throughout history in many different types of cuisines for their spice and flavor, and these spices may also provide a number of health benefits.
  • Learn more about the production and marketing of ginger and turmeric and see how to harvest, clean and package these spice crops.
  • This educational event will include presentations, demonstrations and a field visit.
  • More details on the Field Day Agenda will be available soon.
  • If you are a person with a disability and desire any assistive devices, services or other accommodations to participate in this activity, please contact the Horticulture Program office at [email protected] or call (804) 524-5960 / TDD (800) 828-1120 during business hours of 8 am. and 5 p.m. to discuss accommodations five days prior to the event.


Conferences, field days and workshops are great ways to expand our farming and gardening knowledge and fill the gaps. Perhaps you are a Beginning Farmer (defined as farmers with less than 10 years’ experience). There are many great regional associations for training new and beginning farmers and ranchers, and one of those I know best is the Future harvest CASA BFTP. This is a region-wide program, open to beginning farmers in  MD, VA, DE—including the Delmarva Peninsula—and DC, WV, and PA.

A free, year-long program with 3 levels from entry-level to advanced.

Applications for the 2019 season are now OPEN!

The BFTP offers a year-long immersive training experience that combines a comprehensive classroom curriculum with hands-on learning at Chesapeake region farms that employ practices that are profitable, protect land and water, and build healthy communities.

The BFTP offers 3 training levels, designed to meet the specific needs of beginning farmers at different stages in their careers.   We offer farmer-to-farmer training opportunities throughout the Chesapeake region, and classroom requirements may be completed in-person or online. We offer training in diverse operation types, including vegetables, fruit, cut flowers, herbs, and livestock at urban, peri-urban, and rural farm settings. The program is also designed with built-in scheduling flexibility to allow new farmers to further their training while maintaining their own farms or other work.

All 3 levels of the program are FREE and trainees receive a host of additional benefits:

  • Free admission to our popular winter conference
  • Free admission to our year-round field days at innovative farms
  • Access to a supportive network of new and experienced farmers
  • FHCASA membership
  • and more!

The final submission deadline is October 15, 2018.

Detailed program information and instructions on how to apply are on our website HERE.  Questions?  Please contact Sarah Sohn, BFTP Director: [email protected].