Houdini fly poses new threat to native pollinators

Karla Salp
Communications

Light-colored Houdini fly grubs found in mason bee nests.
Photo credit: Crown Bees

As if the Asian giant hornet was not enough, the Washington State Department of Agriculture (WSDA) is warning that bees and other pollinators face another invasive threat – the Houdini fly.

Unlike the Asian giant hornet, which attacks and kills honeybees, the Houdini fly threatens native mason bees. Mason bees are small, solitary bees that are one of the first pollinators to emerge in the spring and are excellent pollinators in Washington’s cool climate. They are one of the few reliable early spring pollinators and are increasingly used in orchards to pollinate fruit trees in the spring.

The Houdini fly does not attack mason bees directly. The Houdini fly is a “kleptoparasite” -- it lays its eggs on the pollen meant to be the food for mason bee larvae. When the Houdini fly’s eggs hatch, the fly maggots consume the pollen, leaving the mason bee young to starve. Fully grown, the adult Houdini fly makes an amazing escape that gives it its name: it inflates its head to break through the mud cell walls.

Adult Houdini fly on mason bee nesting tube.
Photo credit: Flickr user gbohne

WSDA received reports from mason bee producers who had been detecting the Houdini fly maggots in their mason bee nests. WSDA first received reports in 2019, but only after mason beekeepers had been finding the maggots for repeated years. Because of this, WSDA believes the Houdini fly has established in Washington State and possibly in other states and can no longer be eradicated.

Managing mason bees to limit Houdini fly

While eradication is not an option, mason bee producers and enthusiasts can take several steps to limit the spread of this pest.

• Harvest mason bee cocoons – Open mason bee nests before they emerge in the spring and destroy Houdini fly maggots.
• Control adult mason bee emergence – If you cannot open nests, place the nesting materials in a fine mesh bag and close it tightly. As the bees emerge, release the mason bees daily and kill any Houdini flies.
• Only use nesting materials that allow you to open, inspect, and harvest cocoons. Visual inspections can greatly reduce Houdini fly populations.
• Before purchasing mason bees, ask the provider how they harvested the bees and whether they inspected the cocoons for Houdini fly. Only purchase pest-free mason bee cocoons.

Video from Crown Bees of Houdini fly

maggots in mason bee nesting materials

While eradication is not possible, using these best management practices will not only help managed mason bees survive but will help wild mason bees as well.

Visit agr.wa.gov/pollinators to learn more about the Houdini fly and how to look for it in your own mason bees.

Potato certification tests find success in Hawaii

Kathy Davis
Communications 

Kay Oakley inspecting seed potato grow fields in Hawaii.

A business trip to Hawaii may sound luxurious. But maybe not so much if what you’re there to do is plant and inspect potato fields. 

Benita Matheson and Kay Oakley with WSDA’s Plant Services Program traveled to Oahu, Hawaii in November and January to help ensure Washington’s seed potato growers have disease-free planting stock. Their trips were completely funded by grower fees paid into the seed potato certification program. 

Seed potato growers can volunteer to have WSDA certify their seed stock. It requires that some of their seed potatoes be grown out during the winter months and inspected for viruses. 

In the past, these post-harvest grows and testing were done indoors in greenhouses. This is the first year that WSDA collaborated with the Canadian Food Inspection Agency to try outdoor planting. 

The team from Washington, Canada and Hawaii planting
post-harvest seed potato trial field.

“Hawaii has the perfect climate for grow out,” said Matheson, plant inspection supervisor. “Almost all the major seed potato producing states and Canada have been taking their potatoes to be tested there. This puts Washington State’s growing protocol in line with other seed producing states in the nation.”

Seven participating Washington growers provided several pallets of seed potato samples, which were sent to Hawaii by ship, along with the Canadian potato samples. 

In late November, Matheson and Oakley met up with three Canadian growers and staff from E.S. Cropconsult at Twin Bridge Farms on the north shore of Oahu to plant two fields of samples. 

The farm and the Canada-based consulting firm are working with WSDA to understand the unique growing conditions of Hawaii.

Checking paperwork for seed potatoes
ready for shipping to Hawaii. 

 

“Their knowledge of how quickly the plants would grow helped us figure out when to plant and when to come back to do our visual inspections,” Matheson said. 

WSDA plant inspectors returned to Hawaii in January to inspect and test the seed potato field grow-outs. The outcomes have been positive. 

“Growers were happy with the results from this year’s post-harvest testing,” Matheson noted. “They received their test results earlier than previous years, which allows them to make adjustments to their inventory if needed.”

Benita Matheson with a jar of snakes
while visiting Hawaii ag department offices

The success confirms that WSDA will continue to use the Hawaiian field location for future post-harvest testing. 

“We hope to strengthen our seed potato program and provide healthy planting stock,” Matheson concluded. 

Cascadia Grains conference puts a spotlight on local grains

Karla Salp
Communications

With a focus on local grains and food, in this case barley salad,
 the Cascadia Grains Conference brought people together.

A century ago, nearly every community had a grain mill. If the dreams of the attendees at the
Cascadia Grains Conference come true, that’s the direction society will soon head again.

Last Saturday, WSDA joined hundreds of farmers, bakers, millers, brewers, researchers and others to acquire new ideas, network, and learn about growing the local grain community in the Cascadia region, a reference to a growing area that includes all of Washington and other parts of the Pacific Northwest.

The conference embodied WSDA’s “Focus on Food” initiative – diverse people with diverse interests coming together over a common interest: food.

This was most evident in the hands-on cooking classes offered at the conference, which included the opportunity to learn how to make sourdough bagels, puff pastries, and even traditional tortillas – all using local grains.

Whole grain flour and butter come together for puff pastry. 

Those interested in growing local grains could take a farm tour, learn from farmers already growing grains for local mills, and even get the latest research on growing grains locally.

While the local grain movement may bring visions of small farmers, mills, and bakers, using local grains is not just for the small guy. The keynote speaker, Mel Darbyshire, is the head baker at Grand Central Bakery for both Seattle and Portland. She spoke about building the opportunity and overcoming challenges to sourcing local grains in their large and thriving business.

When thinking of grains and their uses, visions of fresh-baked bread often come first to mind. But another loved use of grains is for brewing and distilling. Not only were brewers able to connect with growers and talk about growing malt, but attendees had the opportunity to taste several new brews released just for the conference.

The conference was a unique opportunity to bring all sectors – literally from farmer to consumer – together with the goal of improving the availability and viability of local grain economies.


To learn more, visit the Cascadia Grains Conference webpage and watch for future conferences and local events.

WSDA asks beekeepers to look for and report Asian giant hornet

Karla Salp
Communications

This year when beekeepers receive their annual reminder to register their hives, they will receive something else as well – a call to action to report Asian giant hornet sightings and attacks.

Asian giant hornets are the world’s largest hornet. While they will eat various types of insects, they have a favorite: honeybees. A handful of Asian giant hornets can kill an entire hive of bees in just a few short hours. They then take over the hive and defend it as their own, taking the brood and feeding them to their own young.

In December, WSDA received and confirmed four reports of Asian giant hornet in the areas of Blaine and Bellingham.

Identifying Asian giant hornet

You can spot an Asian giant hornet by a few characteristics:

• Usually 1.5 - 2 inches long
• Large orange/yellow heads with prominent eyes
• Black and yellow striped abdomen
• Form large colonies that usually nest in the ground

Asian giant hornet attacks

You may not see Asian giant hornets themselves, but you may see the aftermath of an Asian giant hornet attack. These hornets will leave piles of dead bees, most of them headless, outside their beehive, as shown in the photos below.

Bee kill photos courtesy of Teddy McFall

Reporting sightings/attacks

If you believe you have seen an Asian giant hornet or if a beekeeper has noticed the aftermath of an attack, we want to hear about it. There are several ways to report:

• Use the online reporting form at agr.wa.gov/hornets
• Email pestprogram@agr.wa.gov
• Call 1-800-443-6684

When reporting a sighting, please provide as much of the following details as possible:

• Photos of the hornet or beehive damage.
• Your name and contact information.
• The location where the hornet was spotted or the location of the impacted hives.
• Description of the loss or damage to a hive (if photos are not available.) 
• Date or approximate date observed.
• Direction of flight when the hornet flew away. 

Asian giant hornet imposters

Don’t be fooled! Several native species can be mistaken for the Asian giant hornet.

Paper wasp 

Paper wasps are more slender and smaller overall compared to the Asian giant hornet. They also do not have an orange/yellow head.

Bald-faced hornets 

Bald-faced hornets are about an inch long and are mostly black with white stripes and spots.

Yellow jacket  

Photo credit: M. Asche

Yellow jackets are less than an inch long. They have distinctly yellow faces with a black area near the top of the head.

Elm sawfly 

Photo credit: Neil Boyle

The elm sawfly can be as large, or larger, than the Asian giant hornet. They have a black face and yellow stripes, but they lack a stinger.

Use extreme caution near Asian giant hornets

Asian giant hornet abdomen and stinger

Asian giant hornets have a much longer stinger than honeybees. Typical beekeeping attire will not protect you from Asian giant hornet stings. Additionally, their venom is more toxic than that of local honeybees and wasps and they have a comparatively greater supply of the venom as well.

Asian giant hornets can sting repeatedly. Those who are allergic to bee or wasp stings should never approach an Asian giant hornet.

Never try to remove an Asian giant hornet nest. If you find an Asian giant hornet nest, report it immediately to WSDA.

Asian giant hornets are not generally aggressive towards humans, pets, or other mammals, but they can attack if they feel threatened. Asian giant hornet stings – especially repeated stings – can require medical attention, even in those who are not normally allergic to bee or wasp stings. Several hornet-related deaths occur each year where they are native in Asia. 

Pest Alert: Asian giant hornet

Chris McGann
Communications

The Asian giant hornet found near the Canadian border earlier this month.
 Its enormous size and yellow head are unique to this invasive species. 

This month, WSDA entomologists identified a large hornet found near the Canadian border as an
Asian giant hornet (Vespa mandarinia), an invasive species not previously found in Washington State.

Although it is not typically aggressive toward humans, this unwelcome pest can inflict a powerful sting and also represents a threat to honeybees, for which they have a voracious appetite.

On Dec. 8, a resident in Blaine near the Canadian border reported an unusually large hornet they found on their property. Two days later, WSDA visited the site, collected the specimen, which was dead, and confirmed its identity a short time later.

The resident also reported seeing a live giant hornet at a humming bird feeder before it retreated into a nearby forest.

WSDA and Washington State Department of Health (DOH) officials ask people in the area to be on the lookout for and take precautions to avoid contact with these large bugs.

Adults can be nearly two inches long, have a distinctly light-orange head with
prominent black eyes, a black thorax and a black/yellow striped abdomen. 

The invasive hornets are typically almost an inch and a half long and are distinguished by their large yellow heads.

Asian giant hornets nest in the ground. Though they are typically not interested in humans, pets or large animals, they can inflict a nasty sting if threatened or their nest is disturbed.

Asian giant hornets are typically dormant over the winter, and are most often seen from July through October.

Health advice 

DOH advises individuals to take preventative measures in the outdoors by keeping food and drink covered or under screens, and cleaning up by disposing food and garbage properly. People should avoid swatting at the hornets, which may cause these insects to sting.

If you are stung, DOH recommends washing the site thoroughly with soap and water and applying ice or a cold compress to reduce swelling. The agency also recommends an antihistamine or use of an anti-itch cream to reduce itching if necessary. If you are stung multiple times or have symptoms of a severe reaction following a sting, call 911 or seek medical care immediately.

Asian giant hornets are not usually aggressive, but because
of their size and stinger, it's best to avoid them.  

Additional information about bee and wasp stings and prevention measures can be found on the DOH website.

A threat to bees

Asian giant hornets feed on insects and are of particular concern to beekeepers because they are capable of quickly destroying honeybee hives.

This is the first time this invasive species has been detected in Washington State. In August, a large colony of Asian giant hornets was discovered and subsequently destroyed in British Columbia. The BC Ministry of Agriculture issued a pest alert about the detection in September.

Responding to the Asian giant hornet 

In 2020, WSDA will conduct outreach to generate public assistance in looking out for the Asian giant hornet and reporting any detections to the WSDA Pest Program.

Additionally, WSDA is preparing plans to set traps in the Blaine area to monitor for Asian giant hornets.

If you think you may have spotted an Asian giant hornet, report it to WSDA’s pest program and, if possible, include a photo.