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, 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

Gall Insects

Gall Insects: Click to view Rabbit Brush Galls made by a tephritid fly (Aciurina trixa.) Image courtesy and copyright Jim Cane
Rabbit Brush Galls
made by a tephritid fly Aciurina trixa
Image courtesy and Copyright Jim Cane
Fly identification courtesy Gary Dodson

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

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:

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

Antlions and Tiger Beetles

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