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Garlic Mustard (Allaria petiolata)

The bane of woodlands!!! This non-native plant can quickly overrun a woodland or savanna with a “take no prisoners” approach. When we purchased our land in 2005, the remnant oak-hickory woodland was a garlic mustard monoculture. We began in earnest to remove it.



Working smarter rather than harder, I use knowledge when I need workarounds. Determining the best answer for my goals and my unique piece of land requires a hybrid system of academic studies, biological sciences, and a dash of anecdotal evidence. I’m sharing in hopes it helps you, too.

Helpful Garlic Mustard Facts

  • Can self pollinate (Anderson et al 1996, Chapman et al 2012)
  • Seedbank persistance can be 3 years (Nuzzo 1991)
  • Seeds dispersed via foot traffic, animal fur, and water movement and not by wind (Cavers et al 1978)

Management Requires a Combination of Tools

Garlic mustard greens up in spring early, before many of the native plants. This is convenient.  Management can be timed so no collateral damage to spring ephemerals occur.

Herbiciding

When we began controlling garlic mustard, we sprayed rosettes with 2% glyphosate in spring and again in the fall. Pulling those we missed was necessary follow up. In the first 6 years, we substantially decreased the infestation. But we began to notice deformed garlic mustard plants; they were growing, flowering, and appeared to be setting seed. I do not know if these seeds were viable. Were the plants becoming resistant to glyphosate? In 2011, we switched herbicides to Progeny® and are having better success. Whatever herbicide you choose, read and follow the label directions.

Hand pulling

There’s good news! You don’t always need to bag what you pull. Pull the plant when it’s in bloom but not yet setting seed (putting up its silenes) and you can let it decay without extra work! Chapman et al wrote in 2012 that, “uprooting plants at the flowering stage prevented production of any viable seed, while early- and late-fruiting plants were still able to produce viable seed (Chapman et al 2012).

The study further demonstrated height and seed production were correlated; 13” or shorter plants had low seed viability and 16” or taller plants had high seed viability (Chapman et al 2012). The plant’s phenological stage is also a significant “tell;” late-fruiting plants (silenes only) had significantly more viable seed than early-fruiting plants (silenes visible but flowers still attached) (Chapman et al 2012).

Mowing or weed whacking

Hand pulling is effective but may not be practical. Mowing or weed whacking is effective for 2 reasons. Cutting at the ground level “resulted in 99% mortality and reduced seed production to virtually zero” (Nuzzo 1991). Cutting around 4” high had 74% mortality and 98% seed reduction (Nuzzo 1991, Chapman et al 2012). Mowed plants late in the season typically do not regrow after mowing (Cavers et al 1978). Yet some may appear to resprout, but they lack the stored resources after bolting and will not produce viable seed (Chapman et al 2012). Aside from this paper providing evidence that mowing is effective, reasoning out what we know about the flowering stages discussed above with hand pulling provides further corroboration.

We weed whack the larger patches as a triage method when we don’t have time to pull the plants before they set seed.

Fire

There are a couple ways to use fire – prescribed burns and flame weeding.

Prescribed burns can be effective at the proper intensity.  “Low-intensity fire did not affect the incidence of A. petiolata  but mid-intensity reduced rosettes” (Nuzzo 1991). In a woodland setting where the fuels are leaf litter, a general way to think of fire intensity is to think of humidity. A low-intensity fire would occur when there was high humidity, either in the air or in the leaf litter – perhaps morning or evening.

Flame weeding uses a backpack flame weeder works similar to herbiciding — a particular plant is targeted and zapped. Fire wandering away from the target is something to be prepared for but if done when humidity is high or when morning dew remains.

Grazing

Grazing isn’t an effective tool for garlic mustard control. The plant contains a chemical that deters herbivory (Chapman et al 2012) and can add an unpleasant flavor to milk from animals grazing this (Cavers et al 1978). Unfortunately, we can’t depend on deer to graze it either; they find it “completely inedible” (Kalisz et al 2014). And more unfortunate, where deer are abundant so is garlic mustard because they depress native plants with their grazing.

Combine Management Tools

Using different management techniques and tools ensures biodiversity and can save resources! As much as we all want a single “magic bullet” there isn’t one. Mix and match these management tools and planning follow up ensures success.

The native plants returned once we controlled the garlic mustard. Plants that we now enjoy that were suppressed include shooting star, Indian pipe, bellwort, wild geranium, wood anemone, solomon’s seal, false Solomon seal, and yellow pimpernel to name a few. Diversity is the key to a good healthy environment.

Below is a picture of our “purple carpet” of wild geranium. When these bloom, the woods have a wonderful light perfumely aroma!

The wild geraniums carpet the woods as the spring ephemerals senesce.

References

Anderson, Roger C., Dhillion, Shivcharn S. and Kelley, Timothy M. (1996), Aspects of the Ecology of an Invasive Plant, Garlic Mustard (Alliaria petiolata), in Central Illinois. Restoration Ecology, 4: 181-191.

Cavers, Paul B., Heagy, Muriel I., & Kokron, Robert F. (1979). The biology of canadian weeds.: 35. Alliaria petiolata (M. Bieb.) Cavara and Grande. Canadian Journal of Plant Science59(1), 217-229.

Chapman, Julia I, Philip D. Cantino, Brian C. McCarthy. 2012. Seed Production in Garlic Mustard (Alliaria petiolata) Prevented by Some Methods of Manual Removal.” Natural Areas Journal 32(3): 305-315.

Kalisz, Susan & Spigler, Rachel & Horvitz, Carol. (2014). In a long-term experimental demography study, excluding ungulates reversed invader’s explosive population growth rate and restored natives. Proceedings of the National Academy of Sciences of the United States of America. 111. 10.1073/pnas.1310121111.

Nuzzo V. 1991.  Experimental control of garlic mustard [Alliaria petiolata (Bieb.) Cavara & Grande] in northern Illinois using fire, herbicide, and cutting. Natural Areas Journal 11: 158-167.




Poison Ivy – Live and Let Live

I haven’t thought about poison ivy (Toxicodendron radicans) in a very long time. When a friend sent two photos of it for ID confirmation last week, it became a highlight of my week. As we discussed this plant, the initial response was to get rid of it. Yet it’s native and wildlife depend on native plants. How many depend on this “unpopular” plant? I had to know.

As humans, we immediately want to eradicate anything that might cause us harm. Rather than learn to live with it and understand its value, our reaction is to kill it and remove it.

What if…we left it?

Electing to live in harmony with poison ivy means my small piece of the earth could gain from the diversity and benefits of this native plant and I could keep myself safe. Solid identification skills, a grasp of what makes it hazardous, and a list of wildlife using the plant makes living with poison ivy safe and enjoyable.

Wildlife Uses Poison Ivy

Studying the biota as we restore our land’s native ecosystems caused me look at these “plants that could hurt me” differently. Each native plant is a host to insects, meaning they require this plant to sustain the next generation. These insects, in turn, are the protein birds, reptiles, amphibians, and small mammals require to raise their young. Berries and seeds are adult food; the babies require protein and that means insects. Aha! I began to look at all native plants with new eyes.

A little research uncovered 153 invertebrates, 48 birds, and 7 mammals that depend on or use this plant in some way to sustain life. The list is at the end. While not an exhaustive list, it is an impressive list. 

Poison Ivy Has Leaves of Three, But…

Poison ivy can be tricky to identify. While the “leaves of three” mantra is what I grew up learning as a way to identify the plant, it was confusing as there are many plants with 3 leaves. Adding to the complexity of this plant is its color changes —  “reddish in the spring; green in the summer; and yellow, orange or red in the fall” (Wilson, nd). And compounding that, poison ivy can be found as a hairy-looking vine climbing a tree, a small shrub, or a mass collection of short plants. However you might encounter it, all parts (roots, stem, leaves) can cause a skin rash.

Poison ivy in spring. Photo by Chris Noll
Poison ivy in spring. Photo by Chris Noll

The oily substance in poison ivy is “…urushiol (oo-roo-shee-ohl). Its name comes from the Japanese word “urushi,” meaning lacquer”(Wilson, nd). When urushiol makes contact with the skin, the body sends the white blood cells to fight this foreign substance. As the body’s immune system neutralizes this foreign agent some normal tissue gets damaged in the process. This damage is what we see on our skin as a rash.

To avoid the negative effects of poison ivy while letting the wildlife enjoy the positive aspects, here’s a couple of websites that offer ID help for all the stages of poison ivy.  Poisonivy.org provides a great ID photo tool. When you’re ready, you can take a quiz to test your skills.

A Listing of Wildlife Using Poison Ivy

This is an impressive but not exhaustive list of wildlife using poison ivy.

Coleoptera (Beetles)

Altica chalybea (Habeck 1988)
Analeptura lineola (Senchina, 2005, Senchina and Summerville 2007)
Apsectus hispidus (Habeck 1988, Senchina 2005)
Astyleiopus variegatus  (Habeck 1988)
Astylidius parvus (Steyskal 1951, Habeck 1988, Senchina 2005)
Astylopus macula (Senchina 2005)
Bassareus brunnipes (Habeck 1988)
Calligrapha floridana (Habeck 1988)
Chalcodermus aeneus (Habeck 1988)
Chauliognathus marginatus (Senchina, 2005)
Chauliognathus pennsylvanicus (Senchina, 2005, Senchina and Summerville 2007)
Cryptorhynchus fuscatus (Habeck 1988, Senchina 2005)
Ctenicera hamatus (Habeck 1988, Senchina 2005)
Derocrepis erythropus (Habeck 1988)
Diplotaxis bidentata (Habeck 1988, Senchina 2005)
Enoclerus rosmarus (Senchina, 2005, Senchina and Summerville 2007)
Euderces picipes – Senchina and Summerville 2007
Eugnamptus collaris (Habeck 1988)
Eupogonius  vestitus (Senchina 2005)
Eusphyrus walshi (Steyskal 1951, Senchina 2005)
Hypothenemus toxicodendri  (Habeck 1988, Senchina 2005)
Leiopus variegatus (Senchina 2005)
Leptostylus albescens (Habeck 1988, Senchina 2005)
Lepturges querci (Habeck 1988, Senchina 2005)
Lepturges signatus (Steyskal 1951, Habeck 1988, Senchina 2005)
Madarellus undulatus  (Habeck 1988, Senchina 2005)
Molorchus sp. – Senchina and Summerville 2007
Oberea ocellata (Senchina 2005)
Orthaltica copalina  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Pachnaeus opalis  (Habeck 1988)
Pachybrachys tridens  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Phyllophaga uklei (Habeck 1988, Senchina 2005)
Pityophthorous consimilis (Senchina 2005)
Pityophthorous rhois (Senchina 2005)
Pityophthorus corruptus (Habeck 1988)
Pityophthorus crinalis (Habeck 1988)
Pityophthorus tutulus (Habeck 1988)
Saperda lateralis (Habeck 1988, Senchina 2005)
Saperda puncticollis (Steyskal 1951, Habeck 1988, Senchina 2005)
Serica vespertina (Habeck 1988, Senchina 2005)
Strangalia acuminata (Senchina, 2005, Senchina and Summerville 2007)
Synchroa punctata  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Thanasimus  dubius (Senchina 2005)
Trischidias atoma (Habeck 1988)
Xyleborus affinis (Habeck 1988, Senchina 2005)
Xyleborus ferrugineus (Habeck 1988)
Xyleborus pecanis (Senchina 2005)

Lepidoptera (Moths and butterflies)

Acronicta impleta (Habeck 1988)
Acronicta longa (Habeck 1988)
Amorbia humerosana (Habeck 1988)
Anavitrinelia pampinaria  (Habeck 1988)
Antepione thisoaria (Habeck 1988)
Archips argyrospila (Habeck 1988)
Caloptilia diversilobiella (Habeck 1988)
Caloptilia ovatiella (Habeck 1988)
Caloptilia rhoifoliella (Habeck 1988)
Cameraria guttifinitella (Habeck 1988)
Celastrina neglecta  (Senchina, 2008b, Senchina and Summerville 2007)
Choristoneura rosaceana (Habeck 1988)
Cingilia  cantenaria  (Habeck 1988)
Dichorda iridaria (Habeck 1988)
Ecpantheria scribonia (Habeck 1988)
Epipaschia superatalis (Habeck 1988)
Epipaschia zeleri (Habeck 1988)
Episimus argutanus (Habeck 1988)
Eutelia furcata (Habeck 1988)
Eutrapela clemataria (Habeck 1988)
Hyphantria cunea (Habeck 1988)
Lambdina fiscellaria somniaria (Habeck 1988)
Lophocampa maculata (Habeck 1988)
Lymantria dispar (Habeck 1988)
Marathyssa basalis (Habeck 1988)
Nystalea eutalanta (Habeck 1988)
Orgyia leucostigma (Habeck 1988)
Oxydia vesulia transponens (Habeck 1988)
Paectes oculatrix (Habeck 1988)
Platynota rostrana (Habeck 1988)
Prolimacodes badia (Habeck 1988)
Sibine stimulea (Habeck 1988)
Sparganothis reticulatana (Habeck 1988)
Stigmella rhoifoliella (Habeck 1988, Steyskal 1951)
Thyridopteryx ephemeraeformis (Habeck 1988)
Xanthotype sp.  (Habeck 1988)

Hymenoptera (Bees, wasps, sawflies)

Agapostemon viriscens (Senchina and Summerville 2007)
Andrena spp (Senchina and Summerville 2007)
Andrena crataegi (Illinois wildflowers website)
Apis mellifera (Senchina and Summerville 2007)
Arge humeralis (Habeck 1988)
Augochlora pura (Senchina and Summerville 2007)
Bombus fervidus (Senchina and Summerville 2007)
Cimbex  americana (Habeck 1988)
Eumenes fraternus (Senchina and Summerville 2007)           
Lasioglossum spp. (Senchina and Summerville 2007)
Osmia lignaria (Senchina and Summerville 2007)
Sceliphron caementarium (Senchina and Summerville 2007)
Vespula sp. (Senchina and Summerville 2007)
Xylocopa sp.  (Senchina and Summerville 2007)

Diptera (Flies)

Anthrax analis  (Senchina and Summerville 2007)
Dasineura rhois (Habeck 1988)
Laphria sp. (Senchina and Summerville 2007)            
Lasioptera sp. (Habeck 1988)

Hemiptera

Alconeura sp. (Habeck 1988)
Aulacorthum rhusifoliae (Habeck 1988)
Carolinaia caricis (Habeck 1988)
Carolinaia carolinensis (Habeck 1988)
Carolinaia rhois (Habeck 1988)
Clastoptera obtusa (Habeck 1988)
Coelidia sp (Habeck 1988)
Cyrpoptus belfragei (Habeck 1988)
Duplaspidiotus claviger (Habeck 1988)
Ferrisia virgata (Habeck 1988)
Glabromyzus schlingere (Habeck 1988)
Graphocephala versuta  (Habeck 1988)
Heterothrips vitis (Habeck 1988)
Lygaeus kalmii  (Senchina and Summerville 2007)
Metcalfa pruinosa (Habeck 1988)
Nezara viridula (Habeck 1988)
Orthezia insignis (Habeck 1988)
Osbornellus rotundus  (Habeck 1988)
Penthemiafloridensis (Habeck 1988)
Phenacoccus pettiti (Habeck 1988)
Pseudaonidia duplex (Habeck 1988)
Pseudococcus longisetosus (Habeck 1988)
Pulvinaria acericola (Habeck 1988)
Pulvinaria floccifera (Habeck 1988)
Pulvinaria rhois (Habeck 1988)
Pulvinaria urbicola (Habeck 1988)
Rugosana querci  (Habeck 1988)
Saissetia oleae (Habeck 1988)
Selenothrips rubrocinctus (Habeck 1988)

Acari (Mites)

Aculops rhois  (BugGuide website)
Aculops toxicophagus (Habeck 1988)
Eriophyes rhois (Habeck 1988)

Birds

Bluebird (Martin et al 1951)
Bobwhite (Martin et al 1951)
Bush-tit (Martin et al 1951)
Catbird (Martin et al 1951)
Cedar waxwing (Martin et al 1951)
Chickadee, Black-capped (Martin et al 1951)
Chickadee, Carolina (Martin et al 1951)
Chickadee, chesnut-backed (Martin et al 1951)
Chickadee, Mountain (Martin et al 1951)
Crow (Martin et al 1951)
Finch, Purple (Martin et al 1951)
Flicker, red-shafted (Martin et al 1951)
Flicker, Yellow-shafted (Habeck 1989, Martin et al 1951)
Grouse (Martin et al 1951)
Junco (Martin et al 1951)
Kinglet, Ruby-crowned (Martin et al 1951)
Magpie, American (Martin et al 1951)
Magpie, Yellow-billed (Martin et al 1951)
Mockingbird (Martin et al 1951)
Pheasant (Martin et al 1951)
Phoebe (Martin et al 1951)
Quail (Martin et al 1951)
Sapsucker, Red-breasted (Martin et al 1951)
Sapsucker, Yellow-bellied (Illinois wildflower website)
Sparrow, Fox (Martin et al 1951)
Sparrow, Golden-crowned (Martin et al 1951)
Sparrow, White-crowned (Martin et al 1951)
Sparrow, White-throated (Martin et al 1951)
Starling (Illinois wildflower website)
Thrasher, Brown (Martin et al 1951)
Thrasher, California (Martin et al 1951)
Thrush, Hermit (Martin et al 1951)
Thrush, Russet-backed (Martin et al 1951)
Thrush, Varied (Martin et al 1951)
Titmouse, Tufted (Martin et al 1951)
Towhee, Spotted (Martin et al 1951)
Turkey, Wild (Martin et al 1951)
Vireo, Warbling (Martin et al 1951)
Vireo, White-eyed (Martin et al 1951)
Warbler, Cape May (Martin et al 1951)
Warbler, Myrtle (Martin et al 1951)
Woodpecker, Downy (Martin et al 1951)
Woodpecker, Hairy (Martin et al 1951)
Woodpecker, pileated (Martin et al 1951)
Woodpecker, Red-bellied (Martin et al 1951)
Woodpecker, Red-cockaded (Martin et al 1951)
Wren, Cactus (Martin et al 1951)
Wren, Carolina (Martin et al 1951)
Wren-tits (Habeck 1989)

Mammals

Black bear (Martin et al 1951)
Cottontail rabbit (Illinois wildflower website)
Deer, mule (Martin et al 1951)
Deer, White-tailed (Illinois wildflower website)
Muskrat (Martin et al 1951)
Pocket mice (Habeck 1989, Martin et al 1951)
Wood rat (Martin et al 1951)

Resources:

BugGuide website, https://bugguide.net/node/view/15740, Accessed 10 May 2020

Ewing, H.E., 2015. “Mites affecting the poison ivy.” The Proceedings of the Iowa Academy of Science, Volume 24

Habeck, Dale H. 1988. Insects associated with poison ivy and their potential as biological control agents. Proceedings VII International Symposium, Rome Italy

Illinois Wildflower website. https://www.illinoiswildflowers.info/trees/plants/poison_ivy.htm. Accessed 13 May 2020.

Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson. 1951. American Wildlife and Plants: A Guide to Wildlife Food Habits. New York: Dover Publications, Inc.

Senchina, David S. 2005. Beetle interactions with poison ivy and poison oak. The Coleopterists Bulletin, 59(2): 328-334.

Senchina, David S. and Keith S. Summerville. 2007. Great diversity of insect floral associates may partially explain ecological success of poison ivy. The Great Lake Entomologist 40(3, 4)

Steyskal, George. 1951. Insects feeding on plants of the Toxicodendron section of the genus Rhus. The Coleopterists Society 5(5/6): 75-77.

Wilson, Stephanie. How Poison Ivy Works. https://science.howstuffworks.com/life/botany/poison-ivy.htm. Accessed 13 May 2020




Gypsy Moth Treatment

Gypsy moth (Lymantria dispar) treatment is happening in Lafayette County, beginning mid-May through August. The day before receiving this announcement, I discovered a rusty-patched bumble bee (Bombus affinis) on our property, a federally endangered insect. While this was a new find, our land supports a number of classified insects (endangered, threatened, and special concern, also referred to as T&E), along with herptiles and birds. Needless to say, I was concerned and had to nail down the details.

If you received a notice about spraying in your county, you can check to see the target sites with the Department of Agriculture (DATCP) interactive map.

What is the killing agent?

Bacillus thuringiensis serotype kurstaki (Btk) is a group of bacteria which makes it a biological control agent. This bio-control agent is different from those where a non-native insect is brought in to kill off a non-native plant. All bio-control measures need a healthy dose of skepticism applied to them — two non-natives don’t make a native. Since Btk is commonly found in our soils, it does not introduce a foreign entity into our ecosystems.

How does Btk work?

I went in search of how Btk does the “dirty deed.” Btk is not a contact insecticide; the insect must ingest it. It is a stomach poison and will only effect the larval feeding stage (i.e., when it is a caterpillar). Andrea Diss-Torrance, Invasive Forest Insects Program Coordinator for the Wisconsin DNR, tells me that “among moths and butterflies, the effect can vary: about a third of species tested are sensitive, about a third are not [a]ffected at all, and about a third have an intermediate level of sensitivity. Btk is degraded by sunlight and very sensitive caterpillars, such as the Eastern tent caterpillar, are no longer [a]ffected about 11 days after application to foliage”(Andrea Diss-Torrance, personal communication, May 3, 2018).

“When Btk is ingested by a susceptible caterpillar, the highly alkaline environment of the caterpillar’s gut triggers the Btk bacterium to release a crystalline protein called an “endotoxin” that poisons the insect’s digestive system. The endotoxin acts by killing cells and dissolving holes in the lining of the insect’s gut. When a mixture of food, Btk spores, and digestive juices leaks through these holes into the insect’s blood, it causes a general infection that kills the caterpillar. Humans and other mammals have highly acidic environments in their stomachs that destroy Btk before it causes infection” (Ellis 2018).

Two types of Btk mixtures

There are two commercial brands of bio-control mixtures being used against the Gypsy Moth: Foray48® and Gypchek®. The DNR determines which to use based on insects listed in the Natural Heritage Inventory. I have repeatedly expressed my concern with this methodology. Current lists for Lafayette County will be insufficient to ascertain if classified species exist because our county is incredibly undersurveyed for insects (and plants for that matter). I suspect few counties have insect surveys covering the county.

Christopher Foelker, Gypsy Moth Unit Supervisor for DATCP, tells me Gypchek® is used in habitats having known T&E species that are in a vulnerable life stage during the treatment times. (Christopher Foelker, personal communication, May 3, 2018). DATCP considers Gypchek® to be less effective than Btk because it deteriorates quickly and has a much shorter window of efficacy. It is a viral insecticide that is specific to the gypsy moth but it iscostly to produce and there are limited amounts. It is manufactured by raising and infecting gypsy moth caterpillars with a virus (NPV-gypsy moth). These infected caterpillars are ground up and suspended in a liquid solution. This solution is Gypchek® and it is applied to the tree canopy.

Since it is a limited resource, state and federal governments agree to use Gypchek® only where rare species are known and not on every area proposed for Btk treatment. Unless a T&E insect is known, Foray48® is used.

Foelker says all the DATCP treatment plans are reviewed by the US Fish and Wildlife and US Forest Service for any potential effects on T&E species. They present any concerns for areas these species might be impacted.

Who else is affected?

Since I seldom take info from just one source, I continued my sleuthing on this topic. Jay Watson, who works in the Bureau of Natural Heritage Conservation,confirmed my suspicions, “Really, the impacts from Btk on other insects is very poorly understood.  I don’t know of any research that has looked at what impact this might have on insects like bumble bees.” (Jay Watson, personal communication, May 3, 2018). He specifically mentioned bumble bees because of our recently discovered rusty-patched bumble bee on our property.

There are two sides to every issue; this one is no different. Diss-Torrance stated, “the effect, or in this case non-effect, of Btk on a wide range of other creatures is very well known as this bacterially based insecticide has been used extensively in agriculture and forestry since the ‘80’s.”

In general, sunlight and other microbes destroy Btk applied to foliage within three to five days, so Btk does not multiply or accumulate in the environment (Ellis 2018). Yet, in a 1998 study, Btk was added to different types of soil in order to determine how the type of soil affected the persistence and concentration of Btk. The results of the study showed insecticidal activity started to decline after a month in one soil, while in another, toxicity was high after six months. The authors of the study noted that even though Btk is considered non-toxic to non-target species, the accumulation and persistence of the Btk toxins could eventually lead to environmental hazards or the selection of Btk-resistant lepidopterans (Wikipedia 2018).

The EPA has studies demonstrating a small level of toxicity to certain fish, a slight toxicity to honey bees at high level doses, and “practically non toxic” at low level doses. It is slightly toxic to the convergent lady beetle (Hippodamia convergens) (EPA 1998). Caterpillars that become ill or die after ingesting Btk are not considered dangerous to birds or other animals that feed on them (Ellis 2018).

I wasn’t thinking there would be a moral to this story when I began researching it, but I believe that there it. The value of citizen science is priceless and saves lives. Wisconsin DNR’s decision-making about gypsy moth treatments relies solely on the information at the Natural Heritage Inventory. The information behind many decisions that mitigate impacts to our natural community and our T&E community originates from citizen scientists.

Sources:

Ellis, Jodie A. (04 May 2018). Exotic Insects Education Coordinator Department of Entomology, Purdue University. Retrieved from https://extension.entm.purdue.edu/GM/PDF/GMquestions.pdf

Entomological Society of America. (May 2018). Is Bt safe for humans to eat?

Environmental Protection Agency. (1998). EPA 6452 Fact Sheet. Retrieved fromhttps://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-006452_01-Aug-98.pdf

Tobin, Patrick C. and Andrew M. Leibhold. “Gypsy Moth” in Encyclopedia of Biological Invasions. (Los Angeles: University of California, 2011): 298-304.

Wikipedia. (04 May 2018). Retrieved from https://en.wikipedia.org/wiki/Bacillus_thuringiensis_kurstaki




LepidopterART

In 2017, our local librarian wanted some artwork for the library. Heidi and I put our heads together and with her fabulous artistic talent, this exhibit was born!! The following text is from the booklet at the library for self-guided tours. I have added, where the whole moth isn’t obvious in the art, the photos that were the inspiration. We are excited to have 2 other libraries interested in this exhibit. Who knew this would turn into a travelling exhibit. Thank you, Heidi, for coordinating this.

Background

Lepidoptera is an order of insects that includes moths and butterflies. The name is derived from the Greek works “lepido” (scale) and “ptera” (wings), referring to the scales that cover the wings and bodies of adults.

Although butterflies easily capture people’s attention, most Lepidopterans are moths. Of the estimated 11,000 moths found in North America, about 1,300 occur in Wisconsin.

Lepidopteran larvae are called caterpillars and have chewing mouth parts for eating vegetation. Adults have scale-covered wings and in some, their mouth parts form a tubular proboscis for sipping nectar. Some adult moths have no moth parts at all since they don’t eat during their short adult phase. Their goal is to find a mate and lay their eggs.

Biographies

Heidi Hankley

Heidi has enjoyed a lifelong interest in nature and art.  Childhood summers were spent roaming the hills around the family cottage in Iowa County and countless hours creating things at the art desk she shared with her siblings.  Heidi studied Wildlife Ecology and Environmental Studies at the University of Wisconsin and went on to earn a Master’s Degree from the University of Idaho focusing on Wilderness Management. As a National Park Service ranger and research assistant, she was able to spend some really wonderful years working in several of our nation’s most beautiful parks.  Today Heidi continues to explore and be inspired by the nature found around her home in the rural Blanchardville area.

 Marci Hess

Marci began studying insects as part of a larger project designed to understand wildlife living on her 46 acres of habitat. Passionate about providing living spaces for wildlife, Marci began learning about and keeping a list of the birds, mammals, amphibians, and reptiles using the native plants, lichens, fungi, bushes, and trees on her land. She knew good management practices required knowledge of who lived there. Four years into this research and it was time to study insects. None of her formal education prepared her for this adventure! As a lifelong learner, it was remarkable how her world expanded. And simultaneously disappointing at how little is known about 80% of the insects sharing our earth. As her research continues, so has her development of photography skills and website design; both necessary tools as sharing these discoveries are half the fun!

Lepidopterart
We held an event at the library to talk about the exhibit. More photos of the event at the end of this blog.

The Exhibits

Forest Moths
Mixed Media, Heidi Hankley

Halysidota tessellaris, Phyllodesma americana
A Halysidota tessellaris (Banded Tussock Moth) and a Phyllodesma americana (American Lappet Moth)

Halysidota tessellaris – Banded Tussock Moth

From the Latin “tessella” (a little square stone); a tessellated pattern is one laid out in a mosaic of small square blocks and refers to the checkered pattern on the forewing. Tussock moth for the tufts of hair on the caterpillar. These hairs are the caterpillar’s defense against predators, not only while feeding on leaves but they also line their cocoon with these when overwintering. The caterpillars enjoy feeding on a variety of deciduous trees, such as birch, blueberry, elm, grape, oak, hickory, walnut, and hazel.

Phyllodesma americana – American Lappet Moth

From the Greek “phyllon” (a leaf) and “desma” (a band); refers to the leaf-mimicking shape of the wings, and the pale bands on the forewing and hindwing. It is unusual to find one of the caterpillars by visually searching their host plants, which include various woody shrubs and trees. This is another moth that overwinters as a pupa.

Scientific names are a combination of Latin and Greek. Understanding the roots of these words helps to create a picture in our minds of what those words mean. Each moth has 2 parts to their scientific name – the genus and the species.

Wavy-lined Emerald Moth, Synchlora aerata
Acrylic, Heidi Hankley

Synchlora aerata, Wavy-lined Emerald Moth
Synchlora aerata, Wavy-lined Emerald Moth

Camouflaged Looper
Mixed media, Heidi Hankley

Lepidopterart
Camouflaged looper inchworm – all three of them!

Looper caterpillars are known generally as inchworms.  They feed on a wide variety of plants but commonly are found on asters. The common name of camouflaged looper comes from the caterpillar’s habitat of attaching flower petals and other plant bits to its back. This serves to disguise them from predators. These moths overwinter as caterpillars is in this decorated form. When it’s time to pupate, they leave their covered flower skins to form a cocoon.

Dreamers
Mixed Media Assemblage, Heidi Hankley
Hermaris thysbe – Hummingbird Clearwing Moth

Do moths and other insects sleep? Sorta kinda!  Insects enter a state of torpor. This can be likened to our sleep habits. A state of torpor is when the insects is physically and mentally at rest. Many insects will be active during a portion of a 24-hour period; whether this is daytime activity or nighttime activity depends on the insect. Most moths are nocturnal, meaning they are active during the night hours. As with all insects, this is a general statement as some moths prefer daylight hours for their activity!

Mothra
Reduction Linocut, Heidi Hankley

Mothra – always on the side of the good and saving the day with her superpowers! Mere mortal moths must employ other means of defense such as camouflaging or startling coloration, or generating foul tasting and smelling chemical compounds.

Camouflaged
Mixed Media, Suminiagashi Marbling, Heidi Hankley
Photo element by Marci Hess
Pheosia rimosa – Black-rimmed Prominent

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Caterpillars resemble young hornworm caterpillars; for this reason the caterpillars are called False Sphinx. They vary in color and may be yellow, lavender, pink, green, brown or nearly black but regardless of the color, the skin is very shiny. Their desired food is the leaves poplars, aspens, and willows, which they eat very systematically. They eat the leaf edges beginning at the base of the leaf and progressing to the tip. These caterpillars will overwinter as pupa in cocoons.

Three moths
Photographs, Marci Hess

 

 

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Cerma cora – Owl-eyed Bird Dropping Moth

There are only 3 species in this genus north of Mexico. This particular species is “Considered rare in most of range and often associated with unusual and/or pristine habitats.” There are few documented occurrences and other than Wisconsin, probably no state has more than five recently verified occurrences. We are very lucky to have found this moth in our county and in our township!  The pupa overwinters in dead wood. Its vulnerability highlights the importance of leaving fallen dead trees and limbs in your woods.

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Paonias myops — Small-eyed Sphinx

There are only 3 species in this genus north of Mexico. The caterpillars are bright green, which disguises them as they feed on the leaves of cherry, hawthorn and serviceberry. Once they have feasted on a leaf, they cut it off at the base. Birds have become quite savvy about noticing damaged leaves and honing in on a dinner for themselves. This practice mitigates that. The adult uses the eyespots on their hindwings as their defense, flashing them as predators near. This style of defense if called a startle defense; visualize yourself as a bird, flying toward a delicious morsel, and as you approach, you suddenly see LARGE eyes staring back at you. Yikes!

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Harrisimemna trisignata – Harris’s Three Spot

This uncommon moth has a most unusual caterpillar that feeds on various woody species. Aside from the beautiful brocade appearance of the moth wings, it’s claim to fame is the unusual appearance of its caterpillar. This black and white caterpillar can look like a fresh bird dropping or a spider! When winter arrives, the caterpillar bores into the wood to survive the cold months.

Moth Mandala
Mixed Media, Heidi Hankley
Photo elements by Marci Hess
Grammia virgo – Virgin Tiger Moth

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This is the largest of the Tiger moths in our area. Like the Salt marsh moth (mentioned before) the caterpillar consumes alkaloids as one of its defenses. Not only is it supposed to taste bad, it has a distasteful odor. This moth overwinters as a caterpillar.

Estigmene acrea – Salt Marsh Moth
Photograph, Marci Hess

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This is a fairly common moth whose caterpillar enjoys a wide variety of food from plants to shrubs and trees and sometimes crops. The Salt marsh moth is part of the commonly-referred-to group of moths known as the Tiger Moths. They are named as such because of their bright orange coloration and many often have black stripes. One of their defenses is to eat alkaloids, found in the plants they prefer. This substance is supposed to be distasteful to predators and the orange coloration is what announces this distaste. This is another moth that overwinters as a pupa.

Eumorpha pandorus – Pandora Sphinx Moth
Photograph, Marci Hess

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Sphinx moths and their caterpillars are large and spectacular! The caterpillars range from yellowish to green to light orange to a burgundy color. The adults are a beautiful greenish and some have neon orange and blue on their hindwings. Find a grapevine or Virginia creeper and you’ll probably find a caterpillar on the underneath side of a leaf. These moths usually overwinter in the soil as pupa.

Scorched Wings
Mixed Media Triptych, Heidi Hankley
Photo elements by Marci Hess
Plagodis phlogosaria – Scorched Wing

Lepidopterart

This moth gets its common name from the brownish-red spots on its wings. This common name also speaks to the origin of the scientific name from Greek “phlogos” (flame) or “phlogistos” (to burn or inflame) or “phlogosis” (inflammation). The inchworms are among the best twig mimics, which is their defense as they munch on various shrubs or trees. Like many other moths, they overwinter as pupa.

Once Heidi had the exhibit on display, we held an event at the library. Heidi offered suminagashi marbling as an activity. Marci had her photography equipment on display and a few unique beetle specimens for folks to see insects close up. Here’s some fun photos of the evening.