Invertebrates Archives - Page 19 of 29

September 13, 2012January 24, 2021

Monarch Butterflies

Click to view a closer view of Andrea Liberatore's photograph of a Monarch butterfly (Danaus plexippus). Courtesy and Copyright 2009 Andrea Liberatore, Photographer — Monarch Butterfly
*Danaus plexippus*
Courtesy & Copyright 2009
Andrea Liberatore, Photographer

Monarch Butterfly Caterpillar
*Danaus plexippus*
Courtesy US FWS, images.fws.gov

Monarch Butterfly Chrysalis
(Enlarged)
*Danaus plexippus*
Courtesy NASA JPL, climate.nasa.gov
Plant a butterfly garden!
Climate Kids: Earth Now

A Rest Stop During the
Monarch Butterfly Migration
Courtesy US FWS, images.fws.gov
Gene Nieminen, Photographer

Click to view a closer view of a Monarch butterfly caterpillar, (Danaus plexippus), Courtesy US FWS, images.fws.gov — Monarch Butterfly
*Danaus plexippus*
Courtesy & Copyright 2009
Andrea Liberatore, Photographer

Monarch Butterfly Caterpillar
*Danaus plexippus*
Courtesy US FWS, images.fws.gov

Monarch Butterfly Chrysalis
(Enlarged)
*Danaus plexippus*
Courtesy NASA JPL, climate.nasa.gov
Plant a butterfly garden!
Climate Kids: Earth Now

A Rest Stop During the
Monarch Butterfly Migration
Courtesy US FWS, images.fws.gov
Gene Nieminen, Photographer

One sure sign that the end of the summer is near are the holes that appear in milkweed leaves this time of year. Take a peek underneath and you might find a great treasure – a chubby caterpillar boldly dressed in yellow, black, and white stripes.

We are currently playing host to two of these voracious larvae at the Stokes Nature Center, satiating their appetites with fresh milkweed leaves in the hopes of witnessing their transformation into a Monarch butterfly.

The incredible story of a Utah monarch begins in southern California in spring. After being dormant throughout winter, an adult female will rouse itself, mate, and begin flying. Monarchs are gliders, meaning they don’t flap their wings much when traveling. Instead they rely on thermal air currents to keep them aloft and moving – traveling up to 80 miles per day. The female flies until she finds habitat suitable for reproduction. There she will lay up to 400 eggs, exclusively on milkweed plants, which contain a toxin that makes caterpillars and adults inedible, or at least unpalatable, to predators.

Eggs of the second generation hatch in April or May. Larvae eat, undergo metamorphosis and keep traveling until they find an ideal place to mate and lay eggs. The adults then die within a few weeks. The third generation hatches in June and July, traveling still farther north and east. This group’s offspring, the fourth generation of the year, are the caterpillars and butterflies we are currently seeing. And this fourth generation does things a little differently.

Once in their adult stage, eating is priority number one. As temperatures turn cool, migration is triggered and the butterflies head for southern California, back to the same place from which their great-grandparents set out in spring. These butterflies live significantly longer than their parents and grandparents, for successful individuals will survive the winter, and start the entire four-generation process over again next year.

Much of a monarch’s migration remains a mystery, and not just how they know when and where to go, but also what routes they use, what habitats they need along the way, and how humans are affecting their movements.

A number of citizen science projects have been established to try and answer these questions. The Monarch Program monitors migration in the western U.S. each fall. Adults are fitted with a small, sticky tag on their right forewing with a color code specific to the tagging site. As these butterflies are spotted again either during migration or at their final destination, data is collected that can help us better understand their journey.

Recent declines in monarch populations make this research all the more important. You can help by cultivating milkweed in your garden to provide habitat to resident monarchs. Anyone with information on the location of caterpillars or chrysalises can contact local Monarch Program volunteer Ron Hellstern for tagging. For more information on tagging and how you can help monarch butterflies, visit our website at www.wildaboututah.org.

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

Credits:

Images: Courtesy &
Copyright 2009 Andrea Liberatore
Courtesy NASA JPL, climate.nasa.gov
Courtesy US Fish and Wildlife Service,
images.fws.gov
Text: Andrea Liberatore,
Stokes Nature Center in Logan Canyon.
For Information On Tagging:

The Monarch Program: https://www.monarchprogram.org

To tag butterflies found in Cache Valley, please contact Monarch Program volunteer Ron Hellstern at 435-245-9186. Please note that captive caterpillars or chrysalises are easiest to tag, as capturing adults can harm their wings.

Growing milkweed:

Monarch Watch, Propagation (Growing Milkweeds). https://www.monarchwatch.org/milkweed/prop.htm

Additional Reading:

Pyle, Robert Michael. 1981. National Audubon Society: Field Guide to Butterflies, North America. Alfred A. Knopf: New York.

Monarch Watch: Monarch Life Cycle. https://monarchwatch.org/biology/cycle1.htm

National Geographic: Monarch Butterfly (Danaus plexippus). https://animals.nationalgeographic.com/animals/bugs/monarch-butterfly/

NRCS Partners with Farmers, Ranchers to Aid Monarch Butterflies, Posted by Jason Weller, Chief, Natural Resources Conservation Service, on November 12, 2015, USDA Blog, https://blogs.usda.gov/2015/11/12/nrcs-partners-with-farmers-ranchers-to-aid-monarch-butterflies/

NRCS Working Lands for Monarch Butterflies, https://arcg.is/0TjueO

September 6, 2012December 30, 2020

Sunflowers, the late summer feast

Click for a larger view. Image courtesy and copyright Jim Cane — Stand of ornamental sunflowers
in Cache Valley
Image courtesy and Copyright Jim Cane

Honey bee foraging at sunflower
Image courtesy and Copyright Jim Cane

Male *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, https://wildstore.wildsanctuary.com/collections/special-collections: 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, https://www.greatsunflower.org/

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

August 30, 2012April 12, 2018

Gall Insects

Does Utah have more Gauls than Caesar conquered? Certainly not Gaulish peoples of the ancient Roman Empire, but yes, galls of the vegetal kind we have aplenty. Galls are small protuberant growths on plants that are induced hormonally by insects, nematodes, and microbes. For its resident juvenile insect, the gall is a sort of edible fortress.

Some plant galls made by insects persist into winter, when they are more apparent to the naturalist’s eye. Looking at just rabbitbrush, you can find a menagerie of galls shaped like peas, pineapples and spindles that were formed from leaves, buds and stems. No growing tissue is immune to galling. The morphology of a gall is often diagnostic for the species of juvenile insect within. Gall-making insects are all tiny and include gall midges and tephritid flies, cynipid gall wasps, various nondescript moths, and any number of aphids and their kin.

One aphid causes the unsightly brown galls on branch tips of blue spruce, a bane to homeowners. Another aphid forms the pea-shaped galls that swell leaf petioles of aspens and cottonwoods. On sagebrush can be found a leaf gall whose soft surface surpasses that of a puppy’s ear. Oaks and willows host a remarkable diversity of galls. One oak gall was formerly used for tanning leather and making inks because it is rich in tannic acids. The Hessian fly is of grave agricultural importance today because its stem galls weaken wheat stems, causing them to lodge over.

Click to view Tephritid fly (Aciurina bigeloviae) galls on Rabbitbrush. Image courtesy and copyright Jim Cane — Tephritid fly Aciurina bigeloviae
galls on Rabbitbrush
Image courtesy and Copyright Jim Cane
Fly identification courtesy Gary Dodson

But these are exceptions; most galls are of little or no ecological or economic importance. For that reason, most galling insects remain understudied by all but a handful of passionate specialists. Finding plant galls is easy, and once you begin to notice them, you will find it hard to stop. There is no guide to Utah’s plant galls, but we list several starting references for you on our web site.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Photos: Courtesy and Copyright Jim Cane
Text: Jim Cane, Bridgerland Audubon Society
Additional Reading:
Sagebrush Gall made by the fly Rhopalomyia pomum, https://bugguide.net/node/view/200946
Robert P. Wawrzynski, Jeffrey D. Hahn, and Mark E. Ascerno, Insect and Mite Galls, WW-01009 2005,
University of Minnesota Extension, https://www.extension.umn.edu/distribution/horticulture/dg1009.html

Click to view Willow Cone Gall Midge. Image courtesy and copyright Jim Cane — Willow Cone Gall Midge
Image Courtesy and Copyright Jim Cane

Field Guide to Plant Galls of California and Other Western States by Ron Russo
ISBN: 978-0-520-24886-1 https://www.amazon.com/California-Western-States-Natural-History/dp/0520248864
Gall, Wikipedia, Wikimedia Foundation, Inc., https://en.wikipedia.org/wiki/Gall (Accessed Dec 2010)
Gagné R (1989) The plant-feeding gall midges of North America. Cornell University Press, Ithaca
https://www.amazon.com/Plant-Feeding-Midges-North-America-Comstock/dp/0801419182

August 9, 2012January 24, 2021

Spider Silk

Click to view a closer view of Terry Greene's photograph of an orb spider web. Courtesy and Copyright 2011 Terry Greene, Photographer — Orb Spider Web
Contains 3 Types of Silk

Courtesy & Copyright 2011
Terry Greene, Photographer

Spider silk has long been of interest to scientists and engineers for its incredible strength. Silk can be, by weight, a stronger fiber than steel or Kevlar. But new research has discovered that the strength of the individual fibers does not explain the durability of a web, which can remain functional after sustaining extreme stress. The web’s overall design adds to silk’s durability to create a truly functional product.

Spiders utilize silk for many different reasons – transportation, lining burrows, protecting and securing egg cases, and of course for catching prey. Amazingly, an individual spider has the ability to manufacture several different types of silk, which are used for different purposes. In a typical orb-style web there are at least three kinds of silk at work. One is strong and dry, making up the ‘spokes’ of the web. These are the strands upon which the spider itself moves around, so as not to get stuck in its own trap. The strands which create the characteristic spiral pattern are actually made of two types of silk – one is a fine, stretchy fiber, and the other a sticky, glue-like substance. Together, these two silks make up the part of the web responsible for snaring prey.

Another important property of silk is that when stretched the fiber stiffens. As more pressure is applied, the properties of the silk change, allowing it to become stretchy and flexible. If still more pressure is added, the silk stiffens again, until finally it breaks. Originally, this stiff-stretchy-stiff response to stress was viewed as a weakness, but when analyzed as part of an interconnected web, that’s not the case. A team of scientists from MIT noted that webs could be subjected to a lot of force with only minimal damage. Whether the force was localized – for example while ensnaring a large insect – or more widespread over the entire surface – such as pressure from strong winds – the damage incurred by the web was minimal. Only the individual strands that endure the most pressure break, while others stiffen, flex, and remain intact.

Localized damage allows the spider to more often than not simply repair a web instead of abandoning it and starting over. Creating silk and weaving a web is a costly process for a spider – it takes up a lot of the arachnid’s energy. The ability to simply patch the broken parts is a more efficient strategy which requires less energy expenditure and fewer materials than weaving a new web.

Figuring out how to mimic this response to stress on a material could be infinitely useful in the human world. Imagine a skyscraper in an earthquake that fails in one small place where the forces are strongest – not in its entirety as is currently the case. That same earthquake-damaged building might also need only minimal repairs, saving time, money, and materials. Oh the lessons we could learn from one of nature’s smallest creatures…

Thank you to the 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.

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

Credits:
Images: Courtesy & Copyright 2011 Terry Greene
Text: Andrea Liberatore, Stokes Nature Center in Logan Canyon.

Additional Reading:

Chandler, David L. (2012) How Spider Webs Achieve Their Strength. MIT News Office. Available online at: https://web.mit.edu/newsoffice/2012/spider-web-strength-0202.html

National Science Foundation press release (2012) A Spider Web’s Strength Lies in More Than its Silk. Available online at: https://www.nsf.gov/news/news_summ.jsp?cntn_id=123041

Law, Steven (2012) Curious Things About Spider Webs. Available online at: https://www.ksl.com/?nid=968&sid=20488145