Migrating monarchs are fluttering daily into our yard in Vacaville, Calif., one by one, two by two, three by three, and four by four, for a little flight fuel. They're sipping nectar from the Mexican sunflower, Tithonia rotundifolia, and tropical milkweed, Asclepias curassavica.

They're on their way to overwintering sites, such as the Natural Bridges State Park's Monarch Grove Butterfly Natural Preserve, Santa Cruz.

The park's monarch sanctuary "provides a temporary home for thousands of monarchs," according to the website. "In 2016, 8,000 monarch butterflies overwintered at Natural Bridges. From late fall into winter, the monarchs form a 'city in the trees.' The area's mild seaside climate and eucalyptus grove provide a safe place for monarchs to roost until spring."

The numbers typically peak between late October to mid-November. It's an awe-inspiring place, especially if you rear monarchs. And admission is free. The preserve is open to the public from 8 a.m. to sunset daily, or visitors can participate in a free one-hour tour on Saturdays and Sundays at 11 a.m. to 2 p.m.

Meanwhile, scores of monarchs are on their way. Some won't make it. Predators, especially birds, will nail many of them. The weather will deter many others.

We know of at least one that probably won't make it. On Friday, Oct. 27, while we were gathering mllkweed seeds from the Asclepias curassavica, we noticed two lady beetles feasting on aphids.

Wait, what's that beneath that leaf?

Could it be? It was. A monarch caterpillar! Talk about late!

The 'cat is now tucked inside our indoor butterfly habitat, munching on milkweed leaves. With any luck, it will become a mid-life chrysalis and then an adult monarch.

It will take a lot of luck, however, for it to join its buddies in Santa Cruz. Its late start will be exacerbated by the cold, the wind, the rain, the predators....

On a wing and a prayer...

If you're addicted to insects or insect photography, you'll want to see the international award-winning images on the Insect Salon website. Each year the Peoria (Ill.) Camera Club hosts the contest in conjunction with the Entomological Society of America (ESA).

The subjects are primarily insects but can also include spiders and related arthropods, such as barnacles, crabs, lobsters, shrimp, centipedes and millipedes. For your work to be accepted in the Insect Salon showcase, it must score at least 12 points. Those who score 15 are selected medalists.

The ESA, a professional insect-science organization of some 7000 members, showcases these images at its annual conferences. This year's conference, set Nov. 5-8 in Denver, Colo., is appropriately themed   "Ignite. Inspire. Innovate."

The winning photographers this year represent 16 countries: Argentina, Australia, Belgium, Brazil, Canada, Finland, France, Germany, Italy, Malayasia, Slovenia, South Africa, Taiwan, United Arab Emirates, United Kingdom and the United States. Some images are from ESA members, and some are from alumni of the BugShot Macro Photography Workshops.

Malaysia-based photographers anchored the winners' circle:

• The best-of-show medal went to Tommy Teh of Malaysia for "Hunger For Food 3"
• The medal for most unusual: Andrews Ruggen of Argentina for "Convivencia"
• The medal for best storytelling: Alek Low of Malaysia for "Craving For Food"
• The medal for best image from a non-ESA member: Kawawa Wong Yik Siang of Malaysia for "Hungry Jumping Spider"
• The medal for best image from an ESA member: Wei Fu of Ontario, Canada for "Bite Tightly"
• The medal for best image from a Peoria Club Camera member: John Weidman of Peoria, Ill. for "Argiope Securing Grasshopper"

You can view them all by accessing the Insect Salon website and then clicking on the image titles. The site includes the name of the photographer, city/country of residence, and the title of the image.

Due to copyright concerns, I'm not posting the winning images, but posting two of mine that were accepted for the 2017 Insect Salon showcase:

• "Faster than a Speeding Bullet" shows a long-horned bee (Melissodes agilis) in flight, speeding over a Mexican sunflower (Tithonia rotundifolia). This image received one of the 19 honorable mentions. (Image taken with a Nikon D500 camera with a 70-180mm lens. Settings: ISO 2500, f-stop 16, and shutter speed of 1/1000 of a second)
• "Under Attack!" shows a long-horned bee (Melissodes agilis) targeting a Red Admiral butterfly (Vanessa atalanta), also on Tithonia. (Image taken with a Nikon D500 with a 70-180mm lens. Settings: ISO 2000, f-stop 7, and shutter speed of 1/3200 of a second.)

These might inspire you to enter the 2018 Insect Salon competition.

It's a Macro World out there!

In case you missed it, today was National Pumpkin Day.

But it ought to be National Squash Bee Day, because the squash bee (my favorite species is Peponapis pruinosa) is an important pollinator of squash and pumpkins. 

A little bit about the squash bees:

• Squash bees are specialists; not generalists. Squash bees pollinate only the cucurbits or squash family, Cucurbitaceae,  which includes pumpkins, squash, gourds, cucumbers and zucchini. 
• Both the males and females are golden brown with a fuzzy yellow thorax.  The males have a yellow spot on their face.
• Males sleep in the blossoms at night. They're waiting for the females to arrive.
• Squash bees are early risers (they rise before the sun does). They begin pollinating the blossoms as soon as they open in the morning. Other bee species, such as honey bees, don't visit the flowers so early. The squash blossoms close after several hours so there's a limited amount of pollination time.

Wikipedia says: "The name squash bee, also squash and gourd bee, is applied to two related genera of bees in the tribe Eucerini; Peponapis and Xenoglossa."  Both genera are oligoleges (pollen specialists) on the cucurbits.

Another reason why we should be concerned, according to Wikipedia: "Species such as Peponapis pruinosa have been in decline due to several reasons, probably at least in part to pesticide sensitivity."

Happy Squash Bee Day!

UC Davis doctoral student Jackson Audley discusses bark beetles at a recent bark beetle open house, coordinated by Steve Seybold, at the Bohart Museum of Entomology. (Photo by Kathy Keatley Garvey)

It's about the size of a grain of rice but it's a killer.

That's the walnut twig beetle, Pityophthorus juglandis, which in association with a newly described fungus, Geosmithia morbida, causes thousand cankers disease, wreaking havoc on native black walnut trees.

Enter doctoral student Jackson Audley of the Steve Seybold lab, UC  Department of Entomology and Nematology. He will present a seminar on "Protecting Trees from Bark Beetle Attacks Utilizing Semiochemical Repellents: A Case Study with the Walnut Twig Beetle” at a seminar from 4 to 5 p.m., today (Wednesday, Oct. 25) in Room 3001 of the Plant and Environmental Science Building.

The seminar is part of the UC Davis Forest Biology Research Center Seminar Series and his presentation is a preview of his thesis project.

"In this talk I will discuss the theoretical construct of semiochemical repellents for protecting trees from attack by bark beetles and demonstrate the process of developing a repellent tool with my work on the walnut twig beetle, Pityophthorus juglandis, the vector of thousand cankers disease in walnuts," Audley says in his abstract. "Bark beetles can constitute a significant threat to tree health and are a significant disturbance agent in forest ecosystems. Semiochemicals have been successfully utilized to protect individual to stands of susceptible trees from various bark beetle pests. Most of this work has been conducted in coniferophagous bark beetle systems. My work here at UC Davis has been focused on bringing those same techniques into studying an invasive, hardwood-attacking bark beetle system."

Audley received his bachelor's degree in wildlife biology and natural resource recreation and tourism in 2009 from the University of Georgia, and his master's degree in forestry in 2015 from the University of Tennessee. As a master's student, he did research on the walnut twig beetle, including treatment tests.

The walnut twig beetle is believed to be native to Arizona, California, New Mexico and Mexico.  In 2006, plant pathologist Ned Tisserat and entomologist Whitney Cranshaw of Colorado State University identified the pathogen in declining black walnut trees in central Colorado. The disease has now spread throughout much of the United States.

"Often the first symptoms of thousand cankers disease (TCD) are flagging and yellowing leaves and branch dieback," says Seybold, one of the pioneering TCD researchers. He is a chemical ecologist with the USDA Forest Service, Pacific Southwest Research Station, Davis, and a lecturer/researcher with the UC Davis Department of Entomology and Nematology. "Affected branches show sap staining and pinhole-sized beetle holes. Beneath the surface are dark stains caused by the fungus."

"The fungus enters the tree through the feeding or reproductive activities of the beetle, and colonizes and kills the phloem and cambium of the branches and main stem," according to the UC Integrated Statewide Integrated Pest Management Program website, content that's the work of Steve Seybold and entomologist Mary Lou Flint, then associate director of of Urban and Community IPM, and now UC Extension entomologist emerita. The disease gets its name from the large number of dark cankers that rapidly develop on affected branches.

The UC Davis Forest Biology Research Seminars, which began Oct. 11, are held Wednesdays at 4 p.m. in Room 3001 of the Plant and Environmental Science Building.

The remaining schedule includes: 

Nov. 1 – Alison Scott, postdoctoral student, UC Davis Department of Plant Sciences, “The Polyploid Origin and Evolutionary History of California Redwoods”

Nov. 15 – Brian Smithers, Ph.D student, Ecology Graduate Group, "Mechanisms of Range Shifts in Great Basin Sub‐Alpine Bristlecone Pine Forests."

Nov. 29 – Sarah Bisbing, assistant professor, Forest Ecosystem Science, Department of Natural Resources and Environmental Science,  University of Nevada, Reno, "Looking Backward to See Forward: Causes and Consequences of Altered Disturbance and Climate on Western Conifer Forests.”

Dec. 6 ‐ Ryan Tompkins, Forest Silviculturist, U.S. Forest Service/Plumas National Forest, “Sierra Nevada Silviculture in the New World Order: Challenges, Uncertainties, and Opportunities”

For more information, contact David Neale at dbneale@ucdavis.edu.