- Author: Kathy Keatley Garvey
"What's that?" you ask. As you edge closer, it takes off. "Missed it!"
Well, you won't want to miss the Bohart Museum of Entomology's open house on Sunday, Sept. 20 when the theme centers around dragonflies and damselflies.
Dragonfly/damselfly expert Rosser Garrison of the California Department of Food and Agriculture (CDFA) will share his knowledge of dragonflies and damselflies---and showcase some of his global specimens. The open house, the museum's first of the 2015-16 academic year, is from 1 to 4 p.m. in Room 1124 of the Academic Surge Building on Crocker Lane, corner of Crocker Lane and LaRue Road, University of California, Davis. Admission and parking are free.
Did you know that their ancestors existed before dinosaurs did? And that fossil records show that they were the world's largest flying insects, some with wingspans measuring three feet?
“Dragonfly relatives existed before the onset of the dinosaurs---Triassic Period, 250 to 200 million years ago,” Garrison said. Pointing out that these gigantic dragonfly-like insects had wingspans of about three feet, he said that “there was about 20 percent more oxygen in the atmosphere than there is now and other giant insects occurred during that period.”
Garrison will show some of his “Oh, My” dragonflies and videos. “Dragonflies are such neat creatures,” he said. “They are considered beneficial since both larvae---all aquatic--and adults are predators. But one is called the ‘Bee Butcher' and has a reputation for eating honey bees.”
Some interesting facts he related about dragonflies:
- They have a primitive flight mechanism compared to other insects, bees, butterflies, beetles and flies.”
- They, at least many dragonflies, mostly mate on the wing.
- They are not poisonous and they do not sew up people's ears (“devil's darning needles”). However, one group of large dragonflies are called—appropriately—"Darners."
- Larvae have a neat prehensile foldable lower lip unique in insects; it is used for capturing prey like mosquito larvae or even small fish.
Garrison is a senior insect biosystematist in the CDFA's Plant Pest Diagnostics Branch, Sacramento. He identifies various potential invertebrate pests (such as grasshoppers, true bugs and terrestrial mollusks) entering California and determines if they are threats to agricultural commodities.
Garrison's research has resulted in more than 80 published papers dealing with dragonflies, pest insects and includes monographic works and book chapters on tropical ecology and insect systematics.
Garrison was the senior author of two recently published volumes, “Dragonfly Genera of the ew World. An Illustrated and Annotated Key to the Anisoptera” (2006), and “Damselfly Genera of the New World. An Illustrated and Annotated Key to the Zygoptera” (2010), both published by The Johns Hopkins University Press). He has also contributed chapters on invertebrate ecology for “The Food Web of a Tropical Rain Forest” (Chicago University Press, 1996) and “Manu. The Biodiversity of Southeastern Peru” (National Museum of Natural History, 1996).
He has served as the editor of Odonatologica, the quarterly journal of the Societas Internationalis Odonatologica, since January 1998. He has researched and collected dragonflies throughout much of the world, including Puerto Rico, Argentina and Costa Rica.
Garrison received two degrees from the University of California, Berkeley: his master's degree in 1974 and his doctorate in 1979. His doctoral dissertation was on “Population Dynamics and Systematics of the Damselfly genus Enallagma of the western United States (Odonata: Coenagionidae) 1979, published in 1984.
He joined CDFA in December 2004 after serving as a senior biologist/entomologist for Los Angeles County, where he identified all potentially important agricultural invertebrate pests entering the county, and provided insect identification services and advice on their control.
Following the dragonfly/damsel presentation, five other weekend open houses are scheduled:
Saturday, Dec. 5, 1 to 4 p.m.: “Keep Calm and Insect On.”
Sunday, Jan. 10 from 1 to 4 p.m.: “Parasitoid Palooza II”
Saturday, Feb. 13: Biodiversity Museum Day
Saturday, April 16, 10 a.m. to 3 p.m.: UC Davis Picnic Day
Saturday, July 31, 8 to 11 p.m.: “Celebrate Moths.”
The Bohart Museum, directed by Lynn Kimsey, houses a global collection of nearly eight million specimens, including 469 different species of dragonflies.
It is also the home of the seventh largest insect collection in North America, and the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum.
Special attractions include a “live” petting zoo, featuring Madagascar hissing cockroaches, walking sticks and tarantulas. Visitors are invited to hold the insects and photograph them.
The museum's gift shop, open year around, includes T-shirts, sweatshirts, books, jewelry, posters, insect-collecting equipment and insect-themed candy.
The Bohart Museum's regular hours are from 9 a.m. to noon and 1 to 5 p.m. Mondays through Thursdays. The museum is closed to the public on Fridays and on major holidays. Admission is free. Parking is free on weekends.
More information on the Bohart Museum is available by contacting (530) 752-0493 or emailing bmuseum@ucdavis.edu. Tabatha Yang (tabyang@ucdavis.edu) is the public education and outreach coordinator.
- Author: Kathy Keatley Garvey
Whether you call them "praying" mantis or "preying" mantis, one thing is for sure: they are difficult to find.
Tucked away in vegetation and as quiet as "the proverbial mouse" (except praying mantids are more quiet than the "proverbial" mice), they are an eye exercise in "Find me!"
As autumn approaches, our little bee garden is nearing the end of its life. The Mexican sunflower (Tithonia) and lavender are fading rapidly. However, honey bees and other pollinators continue to forage, and the mantids are still hungry. The female mantids, mothers to be, need more high-quality food. Ootheca!
We're all accustomed to seeing praying mantids grab their struggling prey with their spiked forelegs and munch away. Usually that movement alerts us to their whereabouts.
But have you ever just searched for mantids in their habitat? See if you can find them in these photos.
Find the praying mantis!
- Author: Kathy Keatley Garvey
Sometimes in a world of towering skyscrapers, jumbo jets and warehouses big enough to hold a small planet--or at least a state the size of Rhode Island--we don't realize how “small” small is.
Last weekend it was a veritable insect feast on our narrowleafed milkweed. We saw lady beetles feeding on the oleander aphids, the oleander aphids sucking the very life out of the plant (plant juices) and monarch caterpillars polishing off the leaves.
Then the aphids started crawling on the ‘cats, and a whole new perspective of "small" burst into view.
An aphid, at about 1.5mm, is just a little larger than a pinhead. The lady beetle ranges from 0.3 to 0.4 inches (8 to 10 mm), while the monarch caterpillar, depending on the instar, is absolutely huge in comparison. Spell that H.U.G.E. According to MonarchWatch.org, the 1st instar is 2-6mm; 2nd instar, 6-9mm; 3rd instar, 10-14mm; 4th instar, 13-25mm; and 5th instar, 25-45mm.
With two handheld cameras (a Nikon D800 with a 105 macro lens and a Canon EOS 7D with an MPE 65mm lens), we managed to grab a few photos of a tiny aphid crawling on the caterpillar's head, body and tentacle.
That's how "small" small is.
- Author: Kathy Keatley Garvey
Thank you, Mrs. Monarch.
Thank you for laying your eggs on our newly planted narrowleaf milkweed.
We planted the narrowleafed milkweed last spring, hoping we could coax you to come. We laid out a floral welcome mat for you with some of your favorite (adult) foods: a butterfly bush, Mexican sunflowers (Tithonia), and Lantana.
Then we watched. And waited. And watched. And waited.
We saw you nectaring the butterfly bush, the Tithonia and Lantana. We saw Gulf Fritillaries (Agraulis vanillae) chasing you. We saw territorial male sunflower bees (Melissodes aegilis) dive-bombing you. We saw female Valley carpenter bees trying to jerk you around.
You ignored our narrowleafed milkweed. Not a good-enough host plant? Too many oleander aphids for you? Too many lady beetles eating the aphids?
We went from informal to formal. Please, Mrs. Danaus plexippus, lay your eggs on the Asclepias fascicularis. Please. Do. So. Now.
This week we saw your evidence: You did it! You gave us the most beautiful caterpillars we've ever seen.
So, thank you, Mrs. Monarch.
And you, too, Mr. Monarch.
Please come again.
- Author: Kathy Keatley Garvey
Yes, it happens.
We've heard the stories and read some of the scientific literature about what a female praying mantis will do to her partner during the mating process. Sexual cannibalism. She'll bite the head off of her mate and eat it--but the mating process continues unabated. (Except the male has lost his head )
We spotted a mating pair of mantids in our bee garden on Saturday. It was early evening, around 7. They were hidden among the long strands of English lavender.
My camera caught a quick shot of the pair. Yes, two heads. The next picture I took was of the male minus his head. He "lived"--that is, moved around, for about eight hours before expiring. Or, as Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at the University of California, Davis, says: "It will live until it dries up."
Entomology Today weighed in on the sexual cannibalism behavior in its Dec. 22, 2013 edition.
"An urban legend about female praying mantises always eating males during or after mating has circulated for a long time. However, reality is much more complicated.
"Kyle Hurley, an entomology student from the University of Central Arkansas, spent two years observing praying mantises in the lab and made some startling observations. For example, in one out of 45 cases the male actually consumed the female. And in one out of 45 cases, the female removed the head of the male before mating (the males were still able to finish the job)."
Marianne Shockley Robinette, an entomologist at the University of Georgia, was quoted as saying in Entomology Today: "While it has been observed in artificial settings such as laboratories where they're rearing praying mantises, it's rarely been observed in a natural environment.”
Even Snopes, known for debunking urban legends, weighed in on this.
"Yes, the female praying mantis does sometimes eat her mate. In fact, male mantises will often offer themselves up as food to the female during the mating process, and from a biological standpoint this action makes sense: There's no point to mating with a female who might die from a lack of food before she can lay her eggs and pass the father's genes onto the next generation. This doesn't happen all the time, however, and its frequency of occurrence and the reasons for it are still a subject a debate within the entomological world."
The clincher is a YouTube video which clearly shows a female decapitating her mate. If this kind of thing makes you squeamish or queasy, you probably shouldn't watch it. (At least before breakfast.)
But yes, it happens. Nature is not always nice.