Insects Archives - Page 15 of 22

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 2, 2012August 23, 2023

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:

Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

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

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

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

June 7, 2012December 4, 2023

Antlions and Tiger Beetles

Click for a larger view of a Ant Lion pit showing loose sides that slide victims to awaiting jaws at the bottom. Courtesy and Copyright Jim Cane, Photographer — Ant Lion pit
showing loose sides that slide victims
to awaiting jaws at the bottom

Courtesy & Copyright,
Jim Cane, Photographer

Courtesy Wikimedia
Licensed under
GNU Free Documentation License

Click for a larger view of a Tiger Beetle. Courtesy Wikimedia — Ant Lion pit
showing loose sides that slide victims
to awaiting jaws at the bottom

Courtesy & Copyright,
Jim Cane, Photographer

Courtesy Wikimedia
Licensed under
GNU Free Documentation License

Lions and tigers in Utah. Oh my! But fear not unless you are an insect. Ant lions and tiger beetles are fierce, diminutive predators. They are not related to each other and the adults look very different, but the larval stages behave in very similar ways. Both await their prey in earthen lairs.

The conical pits of antlions are found in dry, soft sand, frequently under trees, rock overhangs or house eaves. The larvae dig their pit by crawling backwards in a spiral, plowing with their abdomen. The slope of the sides reaches the angle of repose, which is the steepest angle that the sand can lie before it collapses from a slight disturbance. They embed themselves in the sand at the bottom of the pit with their enormous mandibles open like a bear trap. Any small insect that inadvertently steps over the edge of the pit will tumble to the bottom into waiting jaws.

Tiger beetle larvae also await their prey in a burrow, but theirs is a narrow cylinder. The adult female inserts her eggs in the soil. The young larva uses its formidable mandibles to loosen the surrounding dirt, pushing it to the surface with its head and thorax. The larva’s lower back has a prominent hump with two pairs of large hooks. With these, it anchors itself to the burrow wall, its mandibles poised at soil level. Woe to the insect that walks nearby.

The adults of these two underground predators differ in both appearance and lifestyle. The adult antlion resembles a damsel fly with two pairs of long, transparent wings and a weak, nocturnal flight. The adult does not feed and only lives about 3 weeks. Conversely, the diurnal adult tiger beetle is an aggressive, mobile predator. For its size, it is the fastest running insect. It runs so quickly that it cannot see its prey, so sprints and stops repeatedly to track its intended victim. Tiger beetles come in diverse colors and patterns including bright, iridescent greens and blues. In Utah, look for them on bare ground, such as trails in open country or on dunes.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Images: Courtesy and Copyright Jim Cane
And Courtesy Wikimedia
Theme: Courtesy & Copyright Don Anderson Leaping Lulu
Text & Voice: Linda Kervin, Bridgerland Audubon Society

Additional Reading:

Other Wild About Utah Pieces by Linda Kervin

Tiger Beetles:

https://askabiologist.asu.edu/explore/chasing-tiny-tigers

A field guide to the tiger beetles of the United States and Canada [electronic resource] : identification, natural history, and distribution of the Cicindelidae / David L. Pearson, C. Barry Knisley, and Charles J. Kazilek New York : Oxford University Press, 2005. (via Amazon) https://www.amazon.com/Field-Beetles-United-States-Canada/dp/0199367175/
https://en.wikipedia.org/wiki/Tiger_beetle

Antlions:
https://bugguide.net/node/view/137
https://www2.palomar.edu/users/warmstrong/pljuly97.htm

April 5, 2012March 4, 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:

Additional Reading:

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

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

https://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” https://historytogo.utah.gov/utah_chapters/pioneers_and_cowboys/pestiferousironclads.html