Will a praying mantis eat a caterpillar?

Short answer: Yes.

For several days, we've been watching a resident praying mantis, a female Mantis religiosa, hanging out in our patch of Passiflora (passionflower), the host plant of the Gulf Fritillary butterfly, Agraulis vanillae. 

We grow Passiflora to attract these spectacular orange butterflies with the silver-spangled underwings. They sip nectar, court, mate and lay their eggs.  The eggs hatch into hungry caterpillars and skeletonize our plants, which make us look like  "bad gardeners" but the scenario makes for a "great butterfly habitat."

This year there's no "bad-gardener" look.

The caterpillars haven't skeletonized our plants. 

Then we see Mrs. Religiosa. She does not look gravid, unlike the other mantids in our garden. She is string-bean thin. Praying mantis expert and UC Davis alumnus Lohit Garikipati figures she has already deposited her egg case, or ootheca, and she'll live another month or two.

Last year the Gulf Frits graced us with so many caterpillars that they were the zucchinis of the garden. Too many, too soon. We donated dozens of the 'cats to the Bohart Museum of Entomology, UC Davis, for its open house, and to youngsters engaged in science projects. 

But this year, where are all the caterpillars?

In any pollinator garden, you must expect the pollinators, predators and the prey. Lady beetles and soldier beetles gobble up the butterfly eggs, while birds, spiders and wasps prey on the caterpillars.

We've never seen a praying mantis grab a caterpillar, though. Until now.

Oh, look! A butterfly ballet ever so graceful over the head of string-bean thin Mrs. Religiosa. 

She ignores them. Then she spots a caterpillar. Easy catch, right?

Right.

Yes, a praying mantis will eat a caterpillar.  

For the first butterfly, it was the right place at the right time.

An alfalfa or sulfur butterfly (Colias eurytheme) fluttered into our pollinator garden in Vacaville to sip some nectar from a Mexican sunflower (Tithonia rotundifolia). It lingered for several minutes.

But on another day, several miles away, an alfalfa butterfly wandered into a rural nursery, and splat! Nailed by a yellow sticky trap, which is used to lure, trap, monitor and detect insect pests. 

Second butterfly: wrong place at the wrong time.

Note, however, that in its larval stage, C. eurytheme  is a major pest of alfalfa. 

"There are four to seven generations per year of alfalfa caterpillar, and each generation is closely synchronized with the hay-cutting cycle so that the caterpillar pupates before cutting occurs," according to the UC Statewide Integrated Pest Management Program (UC IPM) website. "Caterpillar populations usually result from a flight of butterflies into the field when the alfalfa is less than 6 inches tall. Extremely large numbers of adults migrating between fields are often present from June to September in the Central Valley and from May to October in the southern desert."

UC IPM points out that factors contributing to economically significant caterpillar numbers are:

• Slow and uneven growth of the crop
• Lack of natural enemies
• Hyperparasites (other parasitoid wasps attacking the natural enemy wasps reducing their numbers)
• Hot, dry weather.

Butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, says 2020 proved to be a major  outbreak year for the alfalfa butterfly in the Sacramento, Yolo and Solano counties. (See butterfly invasion in the Aug. 28, 2020 Bug Squad blog).

Ever seen one in a sticky trap? Often you'll see assorted--and tiny--flies, gnats, beetles, leafminers, psylids and the like. So a yellow butterfly in a yellow sticky trap really stands out.

It's a fitting tribute to see the UC Davis Life Sciences Building recently renamed the Melvin M. and Kathleen C. Green Hall. The building, which houses the UC Davis College of Biological Sciences' research laboratories, faculty and staff, opened in 1997 as an addition to Briggs Hall, home of the UC Davis Department of Entomology and Nematology.

Green Hall memorializes two outstanding scientists--Mel, a geneticist, and wife Kathleen, a biologist.

Melvin Green, who died Oct. 24, 2017 at age 101, was a UC Davis distinguished professor emeritus of molecular and cellular biology who co-founded the UC Davis Genetics Department (now part of the Department of Molecular and Cellular Biology).  Kathleen, who died in 2002, was a UC Davis biologist and a longtime Davis City Council member--she was the first woman elected to serve on the council. A scholarship in her name honors women in science.

Selected the 1971 Davis Citizen of the Year, Kathleen served the community in a number of capacities, including  charter member and president of the League of Women Voters in Davis, and a member of the the Sutter Davis Hospital Board of Directors.

Brilliant Scientist
During Mel Green's 60-year career, he was inducted into the National Academy of Sciences and received two Guggenheim fellowships. He inspired generations of students, faculty and staff.

We never met Kathleen, but we knew Mel as a brilliant scientist and a wonderful conversationalist, with a finely honed sense of humor.  He was a frequent visitor in the halls and offices of the Department of Entomology and Nematology. 

"Mel was a UC Davis icon,"  said Walter Leal, distinguished professor, UC Davis Department of Molecular and Cellular Biology, and a former chair of the entomology department. "I am delighted that his legacy will be attached to a UC Davis building."

Leal and dozens of colleagues spearheaded a movement among the faculty to rename the building. UC Davis Chancellor Gary May approved the name.

"Not many know that Mel, who grew up in the Depression in a Jewish ghetto, became not only a first-generation college graduate in his family but also the first Jewish person to receive a Ph.D. in zoology and biochemistry from the University of Minnesota (1942)," Leal related. "Mel served in the U. S. Army during World War II, and then joined the UC Davis faculty in 1950. He worked until his nineties. During his lengthy and productive career, he made seminal discoveries concerning the nature of mutations using the fruit fly, Drosophila melanogaster. In particular, Mel is known for his discovery of mobile DNA elements."

"Mel would stop by my office on a regular basis just to check on me, talk science, and sometimes to tell a nice joke. For example, in October 2004 he showed up early in the morning and told me: 'Walter, you are screwed!' I asked why and he told me 'Richard Axel and Linda Buck just got the Nobel Prize for their work on olfaction.' I had a good laugh.'"

Mel connected widely and often with UC Davis entomologists, including Bruce Hammock, Hugh Dingle, Lynn Kimsey and Robert Kimsey. Lynn, director of the Bohart Museum of Entomology and a professor of entomology, identified the insect taxonomy for Mel's article, "It Really Is Not a Fruit Fly," appearing in the Sept. 1, 2002 edition of the journal Genetics.

He cared a great deal about the vinegar fly, Drosophila melanogaster," Leal said. "Many people refer to the insect as the 'fruit fly,' but Mel's article articulated why the common name should be the vinegar fly." 

In the article, Green pointed out that the genus Drosophila includes more than 1000 species. He argued that all Drosophila species "should be referred to by their scientific, not their common name."

Mel wrote that "real fruit flies, e.g., the Mediterranean fruit fly, the Oriental fruit fly, and other members of the family Tephritidae, attack unblemished fruit and in heavy infestations cause serious economic damage. In contrast, even if present in enormous numbers, D. melanogaster is innocuous and of no economic importance." 

But to a "layperson's unsophisticated eye," the insects hovering over a fruit bowl, evoke the term, evoke "fruit fly," not "vinegar fly," the geneticist wrote.

The UC Davis campus bursts with buildings named for outstanding faculty, including:

• Asmundson Hall, named for Professor Vigfus Asmundson
• Briggs Hall,named for Professor Fred N. Briggs
• Everson Hall: Professor Gladys Everson
• Hutchison Hall: Professor Claude B. Hutchison
• Kleiber Hall: Professor Max Kleiber
• Bainer Hall: Professor Roy Bainer

And now, the list includes Green Hall, a fitting tribute to the careers of Melvin and Kathleen Green. (See UC Davis news story)

Butterfly expert Robert "Bob" Michael Pyle, founder of the Xerces Society for Invertebrate Conservation, is not only a national award-winning author, a teacher, a public speaker and a conservationist--but now he's on screen.

Well, sort of "on screen." A newly released movie features him and his work.

The Dark Divide chronicles his 1995 journey across one of America's largest undeveloped wildlands, the Gifford Pinchot National Forest. Actor David Cross portrays him.

The plot: "At the urging of his dying wife Thea (Debra Messing), the shy author finds himself in over his head on an epic, life-changing expedition through Washington's Gifford Pinchot National Forest in search of new species of butterflies. Over the course of his six-week adventure, Pyle battles self-doubt, the grueling trail, and the people and creatures who call this forest home. And, somewhere deep in the heart of The Dark Divide, he makes a discovery that challenges everything he knows about the natural world."

You'll have to watch it to see the discovery "that challenges everything."

Pyle, who founded the Xerces Society in 1971, resides in the Columbia River-tributary town of Grays River in southwest Washington.

He draws crowds and questions wherever he goes.

We remember when he toured the Bohart Museum of Entomology, University of California, Davis, in July 2019 with fellow members of the Lepidopterists' Society at their 68th annual meeting.

At the time, Pyle had authored 23 publications, including the comprehensive National Audubon Society Field Guide to North American Butterflies, a go-to reference source. Among his other insect-related books: Chasing Monarchs: Migrating with the Butterflies of Passage, which chronicles his 9,000-mile journey to discover the secrets of the monarchs' annual migration. For his book,  Mariposa Road: The First Butterfly Big Year, Pyle sought to track, firsthand, the 800 species of butterflies known in the United States. The book is a result of his 88,000 mile journey.

While touring the Bohart Museum, "Bob," as he prefers to be called, took a special interest in the Magdalena alpine butterfly, an all-black alpine butterfly, considered "the most elusive of several rare and beautiful species found on the mountain."  He featured the butterfly in his book: Magdalena Mountain: A Novel. 

Pyle visited with many of the Bohart crew, including director Lynn Kimsey, UC Davis professor of entomology; senior scientist Steve Heydon; Jeff Smith, curator of the Lepidoptera collection; and Bohart associate and naturalist Greg Kareofelas.

The Bohart Museum houses nearly eight million specimens, including the California State Insect Survey, as well as a live "petting zoo" (Madagascar hissing cockroaches, walking sticks and tarantulas) and a gift shop. It's located in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis campus, but is temporarily closed due to COVID-19 precautions. More information is available on the website or by contacting bmuseum@ucdavis.edu or (530) 753-0493.)

(Note: The Dark Divide is showing in some theaters and can be streamed online. Xerces Society supporters can save $5 off the streaming rental. Go to The Dark Divide website, select "Virtual Cinema" and then click on the Xerces Society logo. When you reach the checkout, enter XSDD5 for the $5 discount. )