What a delight to see.

We strolled through milkweed patches in the UC Davis Arboretum Thursday noon and saw them.

Monarchs!

The monarch butterflies (Danaus plexippus) are returning from their coastal California overwintering sites. And we're getting new generations.

The UC Davis campus, including the 100-acre UC Davis Arboretum is home to much celebrated flora and fauna, including milkweed and monarchs.

After overwintering along the California coast and in central Mexico, the butterflies flutter north into the United States and Canada in the spring and summer.

However, scientists report that the monarch population in central Mexico declined from 100 million last year to 78 million this year, due to late winter storms, coupled with cold and wet weather, and deforestration.

It's a sure sign of spring, through, when the monarchs return. It's a cause for celebration. Welcome back!

Meanwhile, we're anticipating the arrival of Christine Merlin, assistant professor in Texas A&M's Department of Biology, who will discuss her research on "The Monarch Butterfly Circadian Clock: from Clockwork Mechanisms to Control of Seasonal Migration" when she presents a seminar on Wednesday afternoon, May 31 at the University of California, Davis. The seminar is set from 4:10 p.m. to 5 p.m. in Room 122 of Briggs Hall. Host is molecular geneticist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology.

Mallow is the host plant of the common checkered skipper. This photo, taken of a tree mallow, Lavatera maritima, in the UC Davis Arboretum last spring, shows a foraging honey bee. (Photo by Kathy Keatley Garvey)

We've seen monarchs, Gulf Fritillaries, Western tiger swallowtails, buckeyes, and fiery skippers nectaring on our Mexican sunflowers. But nary a common checkered skipper.

Where, we wondered, are the common checkered skippers?

Just as we were thinking that the common checkered skipper (Pyrgus communis) is not all that common and is not living up to its name, it appeared. Right on cue.

It nectared on the Tithonia and then fluttered away.

It will be back, according to butterfly guru Art Shapiro, distinguished professor of evolution and ecology at UC Davis, and Bohart Museum of Entomology associate Greg Kareofelas.

Why?

Its host plant is mallow and last spring we planted several tree mallows, Lavatera maritima--those drop-dead gorgeous plants with purple-throated pale lavender flowers. A bonus: unlike we Californians, the mallow loves the drought. It does not get thirsty. Plus, it attracts a variety of insects, and blooms much of the year.

Shapiro, who has monitored the Central California population of butterflies for more than four decades and maintains a website, Art's Butterfly World, says this about Pyrgus communis on his educational website:

"This familiar insect appears to be found from sea level to tree line-but things are more complicated than that. At the molecular-genetic level, the populations along our transect are apparently two different species. One is multiple-brooded and occurs as high as Lang Crossing (5000') on the Sierran West slope, and then again in Sierra Valley at 5000' on the East slope. These populations today breed largely on introduced weeds of the genus Malva (in the Sacramento Valley also on the native Alkali Mallow, Malvella leprosa, and on the now rare Checkerblooms, genus Sidalcea, in tule marshes). The other is single-brooded, occurs above 6000' (including Donner and Castle Peak) and breeds only on native Sidalcea. There are very slight 'statistical' differences in pattern, but the genitalia are the same. There seem to be occasional strays of the lowland animal picked up at Donner, mainly late in the season. In southern California occurs a morphospecies, P. albescens, which differs from communis in genitalia and is, like it, multiple-brooded. This animal, however, is molecularly indistinguishable from the univoltine Sierran (genitalic) communis!

"The lowland animal occurs anywhere in the open where hosts are nearby, including urban vacant lots and around ranch buildings and corrals. The montane animal occurs in open coniferous forest with Sidalcea in the understory, and along wood roads and paths. Both visit a great variety of flowers avidly. The flight seasons are March-November in the Central Valley, June-August in montane sites, and late March/April-October at Sierra Valley. (At Sierra Valley the univoltine animal is as close as the top of Yuba Pass.)

"Males are perchers, generally well off the ground, and extremely energetic fliers. They often appear blue in flight (females, lacking the silky hairs, do not)."

Plant mallow and they will come! 

A gray hairsteak, Strymon melinus, on goldenrod in the UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

Nearly 90 butterfly enthusiasts--from senior citizens to pre-schoolers--met up with entomologist Joel Hernandez last Sunday for his second annual talk and tour on "Butterflies Up Close," sponsored by the UC Davis Arboretum.

Hernandez, who has collected and curated insects for 19 years, told of his passion for Lepidoptera, the order of insects that includes butterflies and moths.  "What draws me to butterflies," he said, "is the plethora of different colors and patterns that they display on their wings, as well as their life cycle.”

A 2014 graduate of UC Davis with a bachelor of science degree in entomology, Hernandez currently works for chemical ecologist Steve Seybold as a research/field assistant, and plans to enroll in graduate school.

Blue morpho from Belize

Hernandez displayed butterfly and moth specimens from his California and Belize collections.  His favorite butterfly? The blue morpho, Morpho peleides, a tropical butterfly with wings spanning five to eight inches.

As the tour members left the Wyatt Deck, walking along a shaded path and emerging into the sunlight to a milkweed patch, Hernandez pointed out butterflies and other insects along the way.

Butterflies sighted included:
Monarch, gray hairstreak, Acmon blue, fiery skipper, dusky wing skipper, cabbage white, West Coast lady, gulf fritillary, pygmy blue, Western tiger swallowtail and buckeye.

Tour member Ria de Grassi of Davis checked out the insect activity on the showy milkweed, Asclepias speciosa, noting lady beetles, bees and aphids, but no monarch eggs or caterpillars. A new "Monarch Mom,"  she recently planted milkweed and is beginning to rear a few monarchs for conservation purposes.

The group saw no monarchs but did see other butterflies, including a gray hairstreak, Strymon melinus.

Following the tour, many participants headed for the Bohart Museum of Entomology's open house, featuring the Belize collecting trip.

You might see monarchs, Gulf Fritillaries, Western tiger swallowtails, pipevine swallowtails, and skippers.  You'll learn about butterflies and their needs.

It's a UC Davis Arboretum talk and tour and it's free and open to the public.

Entomologist Joel Hernandez will present a talk and tour on “Butterflies Up Close” on Sunday, Sept. 18 at the UC Davis Arboretum. The event, to begin at 10 a.m. on the Wyatt Deck, is billed as an event to “explore the amazing diversity of butterflies and moths both near and far.” All ages are invited.

Hernandez will also display his own butterfly collection.

Hernandez, who received a bachelor of science degree in entomology from UC Davis in 2014, currently works for the Steve Seybold lab as a research/field assistant. He hopes to attend graduate school and receive his doctorate in entomology.

Hernandez worked for the Sharon Lawler lab for four years, both as a student and as a post-graduation junior specialist. A volunteer at the Bohart Museum of Entomology and the UC Davis Arboretum, he recently participated on a Bohart Museum insect collecting trip with entomologist/Bohart associate Fran Keller.  “It was an amazing experience,” he said.

Hernandez has collected and curated insects for 19 years. “I have a passion for Lepidoptera and would like to use it as a target group for research in graduate school,” he said. “The species of butterfly that interests me the most is the blue morpho. The family of moths that interests me the most and the one I would like to study is Sphingidae.”

"I've been interested in insects ever since I was small," Hernandez said. "It was their unique life histories and morphologies that really propelled my passion for insects and entomology. What draws me to butterflies is the plethora of different colors and patterns that they display on their wings, as well as their life cycle.”

Hernandez presented a well-attended talk and tour on butterflies and moths at the Arboretum last September. Elaine Fingerett, the Arboretum's academic coordinator, chronicled the event in photos.

For more information, contact the Arboretum at (530) 752-4880 or by email, arboretum@ucdavis.edu.