Insects Archives - Page 19 of 20

July 16, 2009December 28, 2018

The Migratory Locust in North America; a post mortem

Vast migratory swarms of flying grasshoppers, or locusts, have periodically scoured arid parts of Africa and the Middle East since Biblical times, devastating crops and causing famine. But did you know that during the 19th century, American homesteaders were likewise plagued by migratory swarms of grasshoppers? The largest swarm passed through Nebraska in June of 1875; it was 110 miles wide, 1800 miles long and more than a 1/4 mile thick, taking five days to pass overhead. It remains the world’s largest recorded insect outbreak.

Here in Utah, at the time of the transcontinental railroad, migratory locusts periodically descended on the homesteads of Mormon settlers, laying up to 1 billion eggs per acre. These ravenous swarms devoured crops, vegetation, even laundry hung out to dry. Around the Great Salt Lake, drowned pickled grasshoppers would wash ahore in vast drifts. Native peoples gathered these salty, sun-dried hoppers for food, a rich source of protein and fat.

Why are we no longer plagued by locust swarms? It appears that the Rocky Mountain locust, went extinct at the turn of the 20th century. Entomologist Jeffrey Lockwood reports that the DNA of specimens preserved in the ice of glaciers in the Wind River Range are like no other grasshopper alive today. The cause of the locust’s abrupt extinction may never be known with certainty, but Lockwood believes that these outbreaks originated in the mountain meadows of the northern Rockies. By the 1880s, these public lands were packed with cattle and sheep, far more than the land could sustain. In a few short years, livestock stripped bare the very core habitats needed by the Rocky Mountain locust, leading to its abrupt extinction and the end of locust swarms in North America.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Text: Jim Cane, Bridgerland Audubon Society
Additional Reading:

Locust: The Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier, Jeffrey Lockwood, Basic Books, 2004,ISBN:9780738208947, http://www.amazon.com/Locust-Devastating-Mysterious-Disappearance-American/dp/0465041671

First and annual report of the United States Entomological commission for the year 1877 relating to the Rocky Mountain locust and the best methods of preventing its injuries and of guarding against its invasions Digitized by Google Books from Harvard University

http://en.wikipedia.org/wiki/Locust

Pestiferous Ironclads: The Grasshopper Problem in Pioneer Utah, Davis Bitton and Linda P Wilcox, Utah Historical Quarterly, 46 #4 as found on “Utah History to Go” http://historytogo.utah.gov/utah_chapters/pioneers_and_cowboys/pestiferousironclads.html

July 2, 2009November 9, 2014

USA National Phenology Network

Audio: mp3 Listen to WildAboutUtah

The study of recurring plant and animal life cycle events is phenology. It is the calendar of nature. This includes when plants flower, when birds migrate and when crops mature. Phenology is relevant to interactions between organisms, seasonal timing and large-scale cycles of water and carbon. Phenology is important to us for many reasons. Farmers need to know when to plant and harvest crops and when to expect pests to emerge. Resource managers use it to monitor and predict drought and assess fire risk. Vacationers want to know when the best fall colors will be or when the wildflower blooms will peak. Timing varies but we can discern patterns.

The USA National Phenology Network monitors the influence of climate on the phenology of plants, animals and landscapes. They encourage people to observe phenological events such as flowering, migrations and egg laying. The Phenology Network provides a place to enter, store and share these observations, which are then compiled and analyzed nationwide. Participants range from individual observers in their own backyards to professional scientists monitoring long-term plots. My husband and I monitor leafing and flowering of lilacs, a key species in the program.

These observations support a wide range of decisions made routinely by citizens, managers, scientists and others. This includes decisions related to allergies, wildfires, pest control, and water management.

I urge you to participate. The National Phenology Network has many public, private and citizen partners. It is a great way to become involved in a nation-wide effort to better understand our environment. All this information and much more is available at the National Phenology website, to which there is a link from our Wild About Utah website.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Text: Linda Kervin, Bridgerland Audubon Society
Additional Reading:

USA National Phenology Network, http://www.usanpn.org/

North American Bird Phenology Program, USGS Patuxent Wildlife Research Center, https://www.pwrc.usgs.gov/bpp/BecomeAParticipant.cfm

June 25, 2009May 12, 2021

Bark Beetle Mania

Hi, I’m Holly Strand of Stokes Nature Center in beautiful Logan Canyon.

For a creature that’s typically less than six millimeters in size, bark beetles certainly have a mammoth footprint. Outbreaks of the tiny insects in forests across western North America have changed millions of trees into shriveled, rust-colored sentinels of a changing ecosystem. In Utah alone, between 1990 and 2005, wood-boring beetles ate their way through more than 466,000 acres which equals 3% of Utah’s total forested area.

Bark beetles are native to our forests and evolved together with their respective hosts. For example, the Douglas-fir beetle evolved with Douglas firs, and the spruce beetle with Engelmann spruce. The mountain pine beetle is the least discriminating. It attacks lodgepole pine, ponderosa pine and, more recently, high elevation species such as whitebark pine, limber pine, and bristlecone pine.

Douglas fir beetle galleries beneath the outer bark 2000 USDA Forest Service — Douglas fir beetle galleries
beneath the outer bark
2000 USDA Forest Service

At healthy population levels, bark beetles renew forests by killing older and declining trees, allowing young, more productive ones to flourish. Female beetles initiate the assault, simultaneously attracting males using pheromones. Within hours the tree becomes the site of a “mass attack” of thousands of beetles. Then the females begin to reproduce. An individual female may lay over 100 eggs. As eggs hatch, larvae construct feeding galleries in the inner bark of the tree. These galleries eventually girdle and kill the tree by cutting off the exchange of nutrients between the roots and the crown of the tree.

Some of the biggest outbreaks in Utah have occurred in the Dixie and the Manti La Sal National Forests. The spruce beetle is responsible for thousands of acres of dead Engelmann spruce trees in both of these forests. The Piñon Ips beetle also thrives in piñon pines in southern UT. Meanwhile, on the other end of the state, the mountain pine beetle is causing serious outbreaks in the Uintas. The Wasatch Range forests have yet to experience extensive diebacks but the mountain pine beetle, Douglas fir beetle and spruce beetle are all causing higher mortality rates than they have in the past.

Certain forestry management practices are partially responsible for the unprecedented bark beetle outbreaks. Dense, homogenous forests with repressed fire regimes are more susceptible to attack. On the other hand, uncrowded, variable age stands composed of lots of different species are healthy and resilient.

Warming climate conditions have also contributed to the severe bark beetle outbreaks. Early fall and late spring freezes, and extremely cold temperatures help repress bark beetle populations. I’ll try to keep this in mind when it’s snowing in June here in Cache Valley. At least our pine trees will be healthy and safe from the bark beetle.

Barbara Bentz, research entomologist with the USDA Forest Service Rocky Mountain Research Station and adjunct faculty member with Utah State University’s Department of Wildland Resources, provided the scientific information for this piece.

Thanks to the USU College of Natural Resources and the Rocky Mountain Power Foundation for supporting research and development of this Wild About Utah topics. For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:

Images: UDSA Forest Service: Assessment and response to bark beetle outbreaks in the Rocky Mountain aea. Report to Congress from Forest Health Protection (see below)

Text: Mary-Ann Muffoletto, Holly Strand

Sources & Additional Reading

Bentz B, Allen CD, Ayres M, Berg E, Carroll A, Hansen M, Hicke J, Joyce L, Logan J,MacFarlane W, MacMahon J, Munson S, Negr?n J, Paine T, Powell J, Raffa K, Régnière J, Reid M, Romme W, Seybold S, Six D, Tomback D, Vandygriff J, Veblen T, White M, Witcosky J, Wood D (2009) Bark Beetle Outbreaks in Western North America: Causes and Consequences. University of Utah Press, ISBN 978-0-87480965-7, 42 p.
http://www.amazon.com/Beetle-Outbreaks-Western-North-America/dp/0874809657

Logan, J.A., Powell, J.A. 2001. Ghost forests, global warming, and the mountain pine beetle (Coleoptera: Scolytidae). Am. Ent. 47(3): 160-172.
http://www.usu.edu/beetle/documents/Logan_Powell01.pdf

Samman, Safiya, Logan, Jesse tech eds. 2000. Assessment and response to bark beetle outbreaks in the Rocky Mountain aea. Report to Congress from Forest Health Protection, Washington Office, Forest Service, U.S. Department of Agriculture. Gen. Tech. Rep. RMRS-GTR-62. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 46 p.
http://www.usu.edu/beetle/documents/2000186_5Samman_Logan.pdf (accessed June 22, 2009)

Morgan, Kory, Racing the clock to stem the spread of the mountain pine beetle, USDA Forest Service, May 11, 2021, https://www.fs.usda.gov/features/racing-clock-stem-spread-mountain-pine-beetle

March 24, 2009July 18, 2020

Bumblebee Queens of Spring

This is Linda Kervin for Bridgerland Audubon Society.

When crocuses are pushing through the snow in your garden, you might see another sign of spring: the flights of bees. Other bees may fly in spring, but few are as early or as boisterous as bumble bees. Utah is home to more than a dozen species of bumble bees, all of who belong to the genus Bombus (which in Greek means buzzing). All have a combination of black and yellow markings on their bodies. Some also have orange bands. Unlike honey bees that pass the winter warmly clustered in hives, bumble bees overwinter as solitary queens, dormant under a few inches of loose soil or leaf litter. These queens are quiescent all winter until warming soil beckons their reawakening to start their colony.

From March to May, watch for a behavior called nest searching, when the big, burly queen bumble bees fly low over the ground, stopping often to investigate holes in the earth or in building foundations. Bumble bees nest in small, insulated cavities, such as abandoned rodent burrows or bird houses. Once the queen finds a suitable nest site, she is out and about, foraging for pollen and nectar to provision her offspring. After a few days she will have sufficient food to begin laying eggs. Like all bees, her offspring progress through four life stages: egg, larva, pupa and adult. In just under a month, her daughters develop into adults, each chewing free of its cocoon.

Click for a larger view of Bombus griseocollis Queen foraging on Hedysarum. Copyright (c) 2008 Jamie Strange — Bombus griseocollis Queen
Foraging on Hedysarum
Copyright © 2008 Jamie Strange

These daughters take over foraging and nest construction duties, leaving the queen to remain in her nest and continue to lay eggs and incubate her brood. Workers are often much smaller than their mother, so don’t expect to see many big bumble bees again until autumn, when next year’s queens start the cycle anew, searching for mates and a spot to spend the winter.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Text: Jamie Strange, USU USDA-ARS Pollinating Insect Research Unit

Additional Reading:

ID a Bumblebee, http://www.ars.usda.gov/Services/docs.htm?docid=10749

Bumblebee Watch, https://www.bumblebeewatch.org/
Bumble Bee Watch is a citizen science project through the partnership of The Xerces Society, the University of Ottawa, Wildlife Preservation Canada, BeeSpotter, The Natural History Museum, London, and the Montreal Insectarium.