Ever wonder why the stink bug stinks?

The stink bug, from the family Pentamodae, is a shield-shaped insect that tomato growers would love to ban from the face of this earth.

Some 50 species exist in California. The adults are either brown or green. Most stink bugs are plant feeders. However, the species of one subfamily prey on other insects, according to the excellent guidebook, California Insects, written by Jerry A. Powell and Charles L. Hogue  and published by the University of California Press.

When a group of us from the UC Davis Department of Entomology worked the soil today at the Harry H. Laidlaw Jr. Honey Bee Research Facility, west of the central UC Davis campus, we encountered several lizards, lots of centipedes and ladybeetles, and several stink bugs.

So, how did the stink bug get its name?  It stinks when it's  disturbed.  It emits a powerful odor from its thoracic glands to ward off predators.

The stink bugs we unearthed didn't stink. Guess we didn't disturb them enough!

Okay, everybody in the pool!

That means bees, too?

It does.  Sweat bees.

You may have noticed the tiny bees--common name “sweat bees” from the family Halictidae--in your swimming pool or pollinating your flowers.

They're attracted to perspiring skin (thus the name “sweat bees”). Sometimes when you're splashing around in the pool, you'll feel a sharp but harmless sting.

UC Davis emeritus professor Robbin Thorp, who researches native pollinators, identified this one (below) as a Lasioglossum  (Dialictus) sp. female. 

A dull metallic gray, brown or blackish in color, they're found throughout California. They nest in ground burrows.  

If you want an excellent book on providing native habitat for these native bees,  you'll want to obtain a copy of Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms, written by Mace Vaughan, Matthew Shepherd, Claire Kremen and Scott Hoffman Black and published by the Xerces Society for Invertebrate Conservation, an international, nonprofit, member-supported organization dedicated to preserving wildlife habitat through the conservation of invertebrates.  For more information, contact the Xerces Society  4828 SE Hawthorne Blvd., Portland, Ore. 92715 or access the Xerces Web site.

They write: "North America is home to about 4000 species of native bees, most of which go overlooked. These insects are not the familiar European honey bee, nor are they wasps or other aggressive stinging insects."

With the decline of honey bees, expect to see more reliance on native bees.

Excerpts from Farming for Bees:

• If enough natural habitat is close by, native bees can provide all of the pollination necessary for many crops
• Fifty-one species of native bees have been observed visiting watermelon, sunflower or tomato in California
• Native pollinators have been shown to nearly triple the production of cherry tomatoes in California

This is the white-belted ringtail dragonfly from the Bohart Museum of Entomology poster. The poster and dragonfly t-shirts are available at the Bohart Museum, 1124 Academic Surge, UC Davis, or at http://bohart.ucdavis.edu.

Others wear a dragonfly on their chest.

As part of its public outreach education program and to showcase the world of insects, the Bohart Museum of Entomology at the University of California, Davis, has created t-shirts featuring a California dragonfly.

The t-shirt, designed by entomology doctoral candidate Fran Keller, features the white-belted ringtail, also known as a gomphid dragonfly, from the family Gomphidae.

UC Davis undergraduate student William Yuen, a part-time employee at the Bohart, traced the insect from a photo taken by Davis nature photographer Greg Kareofelas.

The dragonfly also appears on the Bohart's “California Dragonfly Poster,” the work of Keller and Kareofelas. 

“William is an excellent artist, a brilliant student, a hard worker and has worked in the museum for two years,” said Keller. “I wanted to immortalize him and his talent and for his contributions to the museum.”  

 “This drawing is so precise you could identify this dragonfly by its wing venation,” Keller said.  The insect order (Odonata), family, species name and common name appear beneath the wing.  

Keller said more than 5000 species of dragonflies exist worldwide.  “Dragonflies don't harm people; they don't bite or sting,” she said.   

What else about dragonflies?

• Female dragonflies lay their eggs in or near water.
• They beat their wings about 30 beats per second (bps), compared to a honey bee's 300 bps
• In both their larval and adult stages, dragonflies eat mosquitoes.  The larvae eat mosquito nymphs and other insects. As adults, they grab mosquitoes and other insects in mid-air.

The Bohart Museum is offering both short-sleeved and long-sleeved shirts in various colors online and at the museum, 1124 Academic Surge.  Prices range from $18 to $20.  

Proceeds will benefit the Bohart's insect outreach education program. The museum, directed by entomologist Lynn Kimsey, chair of the Department of Entomology, is home to more than seven million specimens.   

Education coordinator Brian Turner and senior museum scientist Steve Heydon offer tours throughout the year, including the campuswide Picnic Day in the spring. Turner delivers presentations to schools, public libraries, fairs, garden clubs and others as part of the Bohart's outreach efforts.

For more information, see http://bohart.ucdavis.edu/ or contact the museum at (530) 752-0493.

To bee or not to bee.

Not to bee.

The flying insect hovering over the Ruth Risdon Storer Garden,  UC Davis Arboretum, looked like a honey bee or wasp at first glance. It wasn't. It was a hover fly or syphrid fly from the order Diptera (Greek for "two wings") and family Syrphidae.

It's commonly known as a hover fly, drone fly,  flower fly, syrphid fly or  "syrphid," says Robbin Thorp, emeritus professor of entomology at UC Davis who researches native pollinators from his headquarters in the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road.

"These are good honey-bee mimics," he said, "but note the short stubby antennae and bulging face." Also note the large eyes! (Reminiscent of the eyes of the male honey bee, the drone).

The hover fly moves like a helicopter, holding perfectly still for a moment or two, and then darting upward, downward and backward in flight. 

Unlike bees and wasps, syrphids have two wings, not four. Also a syrphid-notable:  black and yellow stripes on their abdomen. The coloring helps fool would-be predators.  

In their larval stages, syrphids dine on plant-sucking pests like tasty aphids, thrips, mealybugs and scales, or munch on decaying matter in the soil or in ponds and streams. 

They're the good guys. And girls. 

These beneficial insects are like the ladybird beetles (aka ladybugs) and lacewings of the garden. In their larval stages, they prey on pests, and in their adult stages, they pollinate flowers. 

Prey 'n pollinate,  that's what they do best.

And hover.