Sunflowers, the late summer feast

Sunflowers, the late summer feast: Click for a larger view of the sunflower garden. Image courtesy and copyright Jim Cane
Stand of ornamental sunflowers
in Cache Valley
Image courtesy and Copyright Jim Cane

Click for a larger view. Image courtesy and copyright Jim CaneHoney bee foraging at sunflower
Image courtesy and Copyright Jim Cane


Click for a larger view. Image courtesy and copyright Jim CaneMale Melissodes bees and a skipper
butterfly sleeping on a sunflower at dusk
Image Courtesy and Copyright Jim Cane

Now, in late summer, the sunny golden blooms of sunflowers adorn gardens, roadsides and wild places across much of the United States. Utah is home to five sunflower species, four of them annuals. You are most likely to see Helianthus annuus, the aptly named “common sunflower”. Early domestication of common sunflower by Plains Indians led to the major oilseed crop that the world enjoys today.

Humans are not the only species seated at the sunflower dining table, however. The grub of one specialist weevil bores in sunflower stalks; as do larvae of 2 long-horned beetles. Another weevil hollows out the seeds. A third decapitates the flowerhead before ovipositing. One moth’s caterpillar gnaws the roots; several cutworm species topple seedling sunflowers, and several more kinds of butterfly caterpillars skeletonize sunflower leaves. In your garden, though, sunflowers generally escape pestilence. Chickadees and both American and Lesser Goldfinches cling to the ripe seed heads to pluck out the nutritious seeds. Listen for the plaintive call of the Lesser Goldfinch which is very distinctive.

[Lesser Goldfinch, Audio recording courtesy Kevin Colver, 7loons.com: Songbirds of the Southwest Canyon Country]

All those sunflower seeds are the direct result of pollination by bees. In the American West, more than 200 species of native bees visit sunflowers for nectar or pollen, a remarkably large fauna for any flower. None is more charming than the male of the bee genus Melissodes. They are discernible by their extra long antennae. Melissodes males dart among sunflowers all day long, seeking willing mates. Come sunset, the males bed down on the flower heads to snooze. They become drowsy enough to pet with your fingertip, and being males, have no sting. So if you have sunflowers at hand, chances are you have Melissodes bees around too. Look over your sunflowers this evening, and you may be lucky enough to find these dozing bachelor bees with their extra long antennae.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Audio: Courtesy Kevin J. Colver, 7loons.com and On Amazon.com
Photos: Courtesy and Copyright Jim Cane
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

LeBuhn, Gretchen, Greenleaf, Sarah, Cohen, David, The Great Sunflower Project, Department of Biology, San Francisco State University, http://www.greatsunflower.org/

Charlet, Larry D., Brewer, Gary J., Sunflower Insect Pest Management in North America, Radcliff’s IPM World Textbook, University of Minnesota, http://ipmworld.umn.edu/chapters/charlet2.htm

Utah Paper Wasps

Adult Poliste Paper Wasp, Courtesy and Copyright 2009 Jim Cane - All Rights Reserved
Adult Poliste Paper Wasp
Copyright © 2009 Jim Cane

We credit the Chinese with inventing paper 2000 years ago, but some social wasps have been making their paper nests for eons. Species of paper wasps are found throughout Utah.

The burly bald-faced hornet workers are patterned in black and white. They place their grey, basketball sized paper nests in tree branches.

Bold yellow and black striped Yellowjackets are the persistent unwelcome guests at summer picnics. They too wrap their round nests in an envelope of paper, but typically place it in a shallow underground chamber. Within the paper envelope, both hornets and yellowjackets have a muti-tiered stack of paper honeycombs, like an inverted pagoda.

Open-faced nest of Polistes  paper wasp with grub-like larvae, Courtesy and Copyright 2009 Jim Cane - All Rights Reserved
Open-faced nest of Polistes
paper wasp with grub-like larvae
Copyright © 2009 Jim Cane

Our most familiar paper wasps belong to the genus Polistes. These are the reddish-brown spindly looking wasps. They make their simple paper nests under your home’s roof eaves and deck railings. A Polistes nest consists of a single inverted paper honeycomb suspended from a stiff, short stalk. There is no paper envelope, so you can readily see the hexagonal paper cells. Around your yard, look for the workers scraping fibers from weathered wood surfaces. Workers mix the chewed fibers with saliva and water, carry the ball of wood pulp home, and add it to the thin sheets of their paper nest. The nest is their nursery, where you can see the queen’s tiny sausage shaped eggs and the fat white grubs. The grubs are fed by their sisters, the workers, who scour the surrounding habitat for insect prey or damaged fruit.

The enclosed nest of the bald-faced hornet Copyright © 2009 Jim Cane - All Rights Reserved
The enclosed nest of the
bald-faced hornet
Copyright © 2009 Jim Cane

Utah has been invaded by the European species Polistes dominula. These interlopers are displacing our native Polistes. Where these European Polistes wasps are a stinging nuisance, you can easily dispatch them at their nests with a sprayed solution of dishwashing detergent and water. Thus stripped of its clever defenders, take the opportunity to admire their homes of paper.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Photo: Courtesy and © Copyright 2009 Jim Cane

Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

http://extension.usu.edu/files/publications/factsheet/yellowjackets-hornets-wasps09.pdf

http://ohioline.osu.edu/hyg-fact/2000/2077.html

http://insects.tamu.edu/fieldguide/cimg348.html

Sphinx Moths

Big Poplar Sphinx
Pachysphinx occidentalis
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

White-lined Sphinx
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

White-lined Sphinx Caterpillar
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

I vividly remember the first time I saw one – a small winged creature whirring from flower to flower in the evening light, its long tongue dipping for nectar within tube-shaped blooms. I was mesmerized, and struggled for a closer look.

If you’re thinking that I must have seen a hummingbird, you would be making a very common mistake. A mistake, in fact, that has given this critter one of its many nicknames. The winged wonder I saw that summer night was a sphinx moth, also called a hummingbird or hawk moth because of their large size and bird-like characteristics.

In all stages of their life, these insects are large. Caterpillars grow to a robust 4 inches in length and adult wingspans can measure more than 5 inches. Sphinx moths are also some of the fastest insects on earth and have been clocked flying at over 30 miles per hour. Their size, speed, and flying ability reflect those of the hummingbird so closely that they are commonly misidentified.

Sphinx moths are a beloved sight in many Utah gardens. However, they also hold a bit of a devious surprise. The larvae, or caterpillar, of one common species of sphinx moth are well known by vegetable gardeners. They are large and bright green with a distinctive horn near their hind end. Like the adults, these larvae go by many names, the most common being the tomato hornworm. Hornworm caterpillars, unlike their adult counterparts, are not beloved by gardeners. They are voracious beasts with the ability to strip the vegetation off a tomato or pepper plant in one day.

Aside from our garden plants, young hornworms of other species feed on a variety of vegetation including willow, poplar and cottonwood trees. Adult moths rely on a host of flowers such as columbine, honeysuckle, larkspur and evening primrose. Here in Utah you might come across one of a handful of different species in the sphinx moth family including the five-spotted hawk moth and the white-lined sphinx. Look for them in the late summer evenings as daylight begins to fade. But be sure to look twice to avoid mistaking them for something they’re not.

And the next time you find a hornworm on your tomatoes, maybe just relocate the little bugger so that you can enjoy it once metamorphosis changes the beast into a beauty.

For more information and pictures of our native sphinx moths, visit our website at www.wildaboututah.org. Thank you to Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.
Credits:

Photos: Courtesy Whitney Cranshaw, Colorado State University, Bugwood.org
            Images licensed under Creative Commons Attribution 3.0 License
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Cranshaw, W.S. 2007. Hornworms and “Hummingbird” Moths. Colorado State University Fact Sheet 5.517. Found online at: http://www.ext.colostate.edu/pubs/insect/05517.pdf

Buchman, Steve. 2010. Pollinator of the Month: Hawk Moths or Sphinx Moths (Sphingidae). US Forest Service. Found online at: http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/hawk_moths.shtml

The Mud-Daubing Wasp

Female Sceliphron caementarium
completing nest cell
Courtesy and
Copyright © 2011 Jim Cane

Pupa of
Sceliphron caementarium
Courtesy and
Copyright © 2011 Jim Cane

The recession has slowed housing starts, but builders of clay dwellings remain busy. Millions of clay homes are built this and every summer in Utah. These dwellings can disintegrate in a summer cloudburst, so you’ll find them beneath overhangs like rock cliffs, or under bridges and the eaves of your house.

These free-standing mud homes are built by a few dozen species of solitary bees and wasps. Among them is the mud dauber, Sceliphron caementarium, a big leggy wasp found throughout Utah. The female wasp constructs hollow clay units one at a time, each the dimensions of a pitted date. The mother mud dauber gathers the wet clay in pellets. At the nest site, she draws the pellet into a ribbon of clay which becomes the next arch of the tubular nest. While working the clay, she audibly buzzes her flight muscles. This vibration visibly liquefies the clay for a few seconds. This strengthens its bond, much as workers in concrete do using large vibrating probes.

The mother wasp then collects spiders, often plucking them straight from their webs after a pitched battle. She permanently paralyzes each spider using her venomous sting. The venom is not lethal. Rather, it is paralytic, keeping the spider alive and fresh but helplessly immobile, a gruesome spider buffet for her grub-like larva to eat. Each hollow nest is packed with a half dozen spiders, one of which receives her egg. In a few weeks time, the growing wasp larva finishes eating its buffet and pupates, becoming dormant for the winter.

Nest building and provisioning by these wasps is a complex result of heritable instincts tailored to local circumstances by learning. It is also a rare trait among insects, most of whom simply lay their eggs and leave. Through observation and manipulative experiments, students of animal behavior have investigated mud-building wasps for well over a century. If you have mud daubers around your home, grab a cool drink, pull up a chair, and enjoy watching their home-making labors.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Images: Courtesy & Copyright Jim Cane, Bridgerland Audubon Society
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

“The Wasps”, Evans, Howard E. and Eberhard, Mary Jane West, 1970. Ann Arbor, University of Michigan Press. 265 p. illus. http://www.amazon.com/Wasps-Howard-Evans/dp/0715360604

“Bees, wasps, and ants : the indispensable role of Hymenoptera in gardens”, Grissell, Eric. 2010, 335 p. http://www.amazon.com/Bees-Wasps-Ants-Indispensable-Hymenoptera/dp/0881929883