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Cofrin Center for Biodiversity

Archive for the ‘Econotes’ Category

National Estuarine Research Reserve Climate Sensitivity Analysis Project

Patrick Robinson

By Chelsea Gunther

 

Patrick Robinson, an adjunct faculty member and Cofrin Center for Biodiversity affiliate, is working on a project examining the effects of climate change, both socially and ecologically. He is working on this project along with other researchers from the University of Wisconsin-Madison, University of Wisconsin-Extension, and National Oceanic and Atmospheric Administration (NOAA) Cooperative Oxford Laboratory in Maryland.

So what is NERRS? It is the National Estuarine Research Reserve System. This system contains 28 diversely located reserves. These reserves are being exposed to several human-related (anthropogenic) and climate-related stressors. The goal of this project is to understand how climate change impacts coastal areas and categorize each reserve based on the results of the anthropogenic and climate impacts. The team plans to present the project results in the fall of 2012.

Whose idea was it? NOAA’s Climate Program Office is developing a partnership with the Office of Ocean and Coastal Resource Management. It is their goal to understand how climate change impacts coastal areas.

How do they plan on doing this? The team is taking a three step approach. First they analyze and synthesize key data describing physical, ecological, and socio-demographic characteristics in these areas. Second, they isolate the main anthropogenic and climate stressors impacting the reserves. Examples of anthropogenic stressors are nutrient enrichment, sedimentation, hypoxia, and physical disturbance including water diversions. Examples of climatic stressors are sea level rise, precipitation frequency and intensity, and drought. Third, from the data they have gathered they will categorize each reserve based on their results to those stressors. Assigning each reserve to different categories allows the research team to better assess the impacts from humans as well as climate on these coastal ecosystems.

Why are they doing this? NOAA hopes to continue further investment in this program and share the information learned with similar projects.  The research will help prioritize future environment vulnerability assessments and planning efforts.

The Red River Breaks are a part of the St. Louis River Freshwater Estuary and Lake Superior National Estuarine Research Reserve.

A new reserve, the Lake Superior NERR, was designated in Wisconsin in 2010 (see lsnerr.uwex.edu/). Patrick, along with many others, worked for over four years on the designation process for the reserve. The Lake Superior NERR represents only the second reserve on the Great Lakes, with the other being in Ohio on Lake Erie. 

Holiday Cluster Flies

Last week I was at a concert where two large fresh-cut trees had just been brought in. I noticed several insects lazily flying about the auditorium and when one landed nearby we recognized it as a cluster fly.  I knew that cluster flies overwinter in attics and walls like Asian Ladybugs, but I wondered if they could also overwintering in Christmas trees. Last year I had seen these same insects shortly after we brought in a fresh-cut Christmas tree as well. Did they come in on the trees?

Cluster fly larvae are non-native imports from Europe.  They are not considered invasive in northeastern Wisconsin because they are parasites on earthworms, which are also not native to our area.  In the autumn adult flies search out protected over-wintering sites. In the wild these would be under bark or in dense vegetation or other crevices in rocky piles or cliff faces. Of course buildings mimic cliff faces to these insects, and the flies will cluster under siding and in walls or attics. Christmas tree farms are likely to provide good overwintering sites if there are brush piles or dead trees or sheds nearby. But it isn’t too likely they could use living Christmas trees successfully because there are few good places for them to hide.

I spoke with UW Madison entomologist Phil Pellitteri who agreed the flies are unlikely to find good winter protection in Christmas trees and suggested that the flies were probably in the building and were roused by warm outside temperatures. Wherever they came from they are slow and easy enough to catch. Unlike other “house” flies, cluster flies do not feed in our houses and are unlikely to spread disease.

Cluster Fly (Phormia rudis). Photo by Gary Fewless.

Cluster Fly (Phormia rudis). Photo by Gary Fewless.

Are cluster flies a pest? That probably depends on how many there are in one place. They can sometimes accumulate inside walls and attics in large numbers. When temperatures rise on warm days some flies become active and make their way into living spaces. Once inside, they are not easily controlled by pesticides. Experts at the Entomology department at Penn State  and UW Extension suggest killing flies trapped in walls or attics might makes matters worse because the dead flies will attract other more onerous pests like carpet beetles that would  invade closets and rugs looking for wool and furs after they devour the flies.

Real Christmas trees are clearly the better choice for the environment when compared with artificial trees. They sequester carbon, produce less pollution and waste when recycled, and tree farms provide habitat that helps to preserve local biodiversity. Sometimes people are worried about that biodiversity, especially insects or spiders, coming inside with their trees. The best way to remove any stowaways is to give the tree a good shake before bringing it in the house. Fresh Christmas trees should never be sprayed with chemical pesticides, which are flammable and environmentally unfriendly. And of course sprays would ruin that wonderful fresh conifer scent.

References:

Phillip Pellitteri, University of Wisconsin Diagnostic Laboratory: http://www.entomology.wisc.edu/diaglab/

Insect Advice from Pennsylvania State Extension: http://ento.psu.edu/extension/factsheets/cluster-flies

University of Wisconsin Extension News: “Homeowners find fall insects unwelcome guests.” http://www.uwex.edu/news/read.cfm?id=153

The Nature Conservancy “Real versus fake Christmas trees” http://www.nature.org/photosmultimedia/real-vs-fake-christmas-trees.xml

Flycatchers Switch to Berrypicking in the Fall

The borders of the Lenfestey Family Courtyard are heavily planted with elderberries and each August and September as they ripen I have great views out my window of the birds that come to feast. There are always the usual bunch, the robins and their young that nested all summer in the Serviceberry, Cardinals of course, and the flocks of Cedar Waxwings that easily navigate the tangle of branches like bands of pirates finding the richest caches of fruit.

Eastern Kingbirds

Eastern Kingbirds foraging on elderberries. Shot through my office window. Note the textbook reflected by the flash.

But there are Eastern Kingbirds joining the party too. Kingbirds rarely visit the courtyard, preferring the open edges of the trail near the ponds where they gracefully dive and roll, capturing flying insects in their pincer-like beaks. It is strange to see them flapping through the dense foliage of the elderberries, where they tip themselves forward off the branches as they clumsily pluck berries one by one. And while they seem a bit unfamiliar with the technique they do manage to gorge themselves with fruit.  Fruit-eating also coincides with a remarkable tolerance in this notoriously aggressive species. Kingbirds will flock together during migration and in their South American wintering grounds.

Scientists have long recognized this feeding switch from insects to fruit in several species of primarily insectivorous birds shortly before and during migration.  It was originally thought that the birds switched to fruit as insect populations declined, but this does not seem to be the case. It was also hypothesized that fruit might provide more calories, but nutrition studies showed that while some species did gain weight on fruit others lost weight (Smith et al. 2007).  Other research has focused on the advantages of feeding on fruit.  Insects require a lot more energy to find and capture and are usually caught on the wing, exposing birds to migrating hawks. Berries offer an easily collected high density food source and the foliage offers cover from hawks and other predators.  Studies have also shown that birds do seek out berries that are highest in proteins and lipids (Parrish, 1996).

Just this year scientists have started to look at micronutrients including antioxidants in fruit. Migration is extremely stressful and scientists speculate that ingesting more antioxidants might improve these birds ability to survive during migration and in tropical wintering grounds where birds are packed closer together (McCue et al. 2010).

It has even been suggested by ornithologist Gene Morton (1971)  that the white tip on the Eastern Kingbird’s tail might analogous to the bright tail feathers of the waxwings. As they forage tail flicks signal food locations to others in the flock .

Regardless of the physiological reasons migratory birds are switching to fruit, the take-home message is strong.  Make sure that migrating birds have access to reliable sources of fruit in the fall. Both Parrish’s and McWilliams’ research suggests that native berries, are superior in nutrition to non-native species. We need to make sure that we preserve native habitats along migratory routes so that birds have reliable high quality food during stop-overs.

Parrish (1996) also argues for us to become better land stewards of our own yards. “Conserving native habitat in a backyard is simple and inexpensive,” he said.  “Many songbirds will even use small, yard-sized patches of these natural landscapes during migration, providing people with exciting opportunities for bird observation–and providing the birds with the critical fuel for a long journey south.”

References

McCue, M. D., O. Sivan, S.R. McWilliams, and B. Pinshow (2010) Tracking the oxidative kinetics of carbohydrates, amino acids, and fatty acids in the house sparrow using exhaled 13CO2. Journal of Experimental Biology, in press.

Parrish, Jeffrey D. (1997) Patterns of Frugivory and Energetic Condition in Nearctic Landbirds during Autumn Migration. The Condor Vol. 99, No. 3 (Aug., 1997), pp. 681-697

Morton, Eugene S. (1971) Food in migration habits of the Eastern Kingbird in Panama. The Auk: 88: 925-926.

Smith, Susan B., Kathleen H. Mcpherson, Jeffrey M. Backer, Barbara J. Pierce, David W. Podlesak, and Scott R. Mcwilliams (2007) Fruit Quality and Consumption by Songbirds During Autumn Migration . The Wilson Journal of Ornithology 119(3):419–428

Turner, Scott (1996) Study shows songbirds switch from bugs to berries to fuel fall migration. Brown University news Bureau. http://www.brown.edu/Administration/News_Bureau/1996-97/96-019.html

Brown, Kewaunee, Shawano, and Oconto Bird Surveys: May 26 to June 24, 2010 by Erin Gnass

As I mentioned in one recent blog posting entitled “May 26, 2010 by Erin Gnass,” I performed bird surveys for the greater part of the month of June for my thesis project—the index of ecological condition model, as applied to northern hardwood forests of Wisconsin. In order to most appropriately create this model, I surveyed additional hardwood forested sites considered to be of poorer forest condition so as to sample across a wide range of environmental condition. This enables the model to be more accurate and effective at calculating forest condition. Therefore, I went in search of hardwood forest sites on both public and private lands near and within heavily managed, fragmented, and human-disturbed or developed areas. Within Brown, Kewaunee, Shawano, and Oconto counties here in east-central Wisconsin, I found 27 sites that I surveyed, with the much-appreciated assistance of Joan Berkopec (the same wonderful volunteer who helped with the Wild Rivers Legacy Forest surveys and the Nicolet National Forest Bird Survey that I described in the two previous posts).

From May 26 until June 24, I observed 49 total species at these 27 additional sites, including the following species of interest:

Seven warblers:  Chestnut-sided, Common Yellowthroat, Mourning, Northern Waterthrush, Ovenbird (in moderate numbers), Pine, and Yellow Warblers

Seven woodpeckers:  Downy, Hairy, Northern Flicker, Pileated, Red-bellied, Red-headed, and Yellow-bellied Sapsucker Woodpeckers

Four flycatchers:  Eastern Phoebe, Eastern Wood-Pewee (in moderate numbers), Great Crested (in moderate numbers), and Least Flycatchers

Three thrushes:  American Robin (in moderate numbers), Veery, and Wood Thurshes

And one vireo:  Red-eyed Vireos (in large numbers)

Please feel free to look at the photographs that I took shown below:

Hardwood forest in Brown County

WI DNR sugar maple forest plot in Shawano County

While scouting out potential survey sites in Brown County, I heard then observed this spectacular Mourning Warbler pictured here

One of two Red-headed Woodpeckers that I found nesting along the pond at the Brown County Pet Exercise Park, which is full of sugar maple hardwoods

Red-headed Woodpecker

One of the two Red-headed Woodpeckers at their nesting cavity site

Thank you to professional photojournalist, Scott Giese, my boyfriend, for taking these additional photographs of me while I completed a bird survey in Brown County:

Me, Erin Gnass, obtaining a GPS coordinate at a bird survey site in Brown County

Me, Erin Gnass, recording data for a bird survey in Brown County

Me, Erin Gnass, trying to obtain a visual observation of a bird during a bird survey in Brown County

June 11-13, 2010: Nicolet National Forest Bird Survey by Erin Gnass

Every year since 1987, a large group of ornithologists have performed breeding bird surveys within the Nicolet National Forest (NNF; see the Nicolet National Forest Bird Survey: (http://www.uwgb.edu/birds/nnf/) in northeastern Wisconsin, now contributing to well over 40,000 records of birds consisting of over 200 total bird species. Whether you are an ornithologist by profession, a volunteer, a student, a back-yard birder, the state’s best expert, or a complete novice who has never seen a Canada Goose in your life, absolutely anyone can come and assist in the survey! Luckily, I was able to be one of the group leaders and engage myself in the survey for the very first time. Having heard about how much fun and exciting it is to participate in such a wonderful annual event, I was not disappointed in the slightest!

On the first day of the survey, I led a small team birders consisting of a young couple and another woman to pine and hardwood forests and a few beautiful bogs. Although the sites were not as biodiversity rich as other sites within the Nicolet National Forest, we were able to observe many interesting but “usual suspect” birds, such as the Ovenbird, Red-eyed Vireo, Chipping Sparrow, Eastern Wood-Pewee, Rose-breasted Grosbeak, American Robin, Brown Creeper, Blue Jay, Black-capped Chickadee, Black-throated Green Warbler, Alder Flycatcher, Yellow-bellied Sapsucker, and many others. After this first morning of surveys, a large group of us, including (some of my favorite ecologist/biologist friends) UWGB undergraduate student, Aaron Groves, former UWGB Environmental Science & Policy graduate student, Kathryn Corio, Ron Eichhorn (who helped the Nature Conservancy and me with the WRLF project), and a few others went out to a bog near the NNF to look for interesting plants and birds. A few of us chased down a Palm Warbler while others observed uncommon plant species. Please see the photographs that I took down at the bottom of this posting. Thank you to all of the botanists in this group who showed me these beautiful plants.

On the second day, graduate student, Nick Walton, joined our group and helped to lead the surveys.  Near the end of one of the last surveys of the day, we heard a nearby soft chickadee-call where we discovered two Boreal Chickadees—the highlight of my entire summer. Not only did these individuals continue singing throughout the remainder survey, they flew low in the trees only ten meters away from us for quite a few minutes. Not many people have the opportunity to view this species in particular because they are considered an uncommon, northern U.S./Canada dwelling species. Thus, when we shared the news with other birders upon returning to the field houses, everyone expressed their surprise and excitement to us. What a thrilling day it was.

I look forward to next summer’s bird surveys at the Nicolet National Forest.

My photographs:

Me, Erin Gnass, leading one of a few bird surveys in a bog within the Nicolet National Forest

One of a few beautiful bogs that we surveyed.

After the first day of surveys, a small group and I went in search of plants and birds around the bog pictured here.

UWGB undergraduate, Aaron Groves, bird watching at the bog.

Ron Eichhorn and Aaron Groves trying to identify a plant.

Aaron Groves, and his mother, former UWGB Environmental Science & Policy graduate student, Kathryn Corio

A stunningly gorgeous carnivorous pitcher plant (Sarracenia purpurea)

Another carnivorous plant, the sundew (Drosera rotundifolia)

Aaron Groves and I found a previously made teepee-like structure on a hill leading down to the bog.

Puddles of Sulfurs

  

puddling sulfurs

Sulfur butterflies puddling in a drainage ditch.

On a weekend in early August on a country road in Door Co., Wisconsin Mike Draney and I were surprised to find ourselves in a cloud of butterflies. Driving along County Road EE in Door County we were scaring up clouds of Clouded Sulfur butterflies (Colias philodice). We stopped and found that they were gathering by the hundreds in the wet mud of the stormwater ditches. We collected several dead butterflies, likely the victims of car traffic, and found that every individual we collected was a male.

Congregations of butterflies at mud puddles, animal dung, or carrion were first recognized in the early 1900s, but surprisingly, scientists still don’t know a lot about why they do it. It was long suspected the behavior was related to nutrients and salts. Flower nectar, while high in carbohydrates, is extremely low in nutrients like salts and amino acids.  Experiments by chemical ecologists S. Smedley and T. Eisner conducted in 1995 confirmed that butterflies do prefer saltier puddles. And since them numerous studies have confirmed that butterflies are seeking sodium or proteins and sometimes other nutrients in the puddles that are scarce in nectar.

Females are not usually seen at puddles, even though it makes sense that they would also be in need these scarce nutrients to produce healthy eggs. In fact it has been demonstrated that males transfer some of the nutrients they collect at puddles to females as “nuptial gifts” during mating that she will then use to provision her eggs. In some cases may give away almost half of their total reserves.  The gift is important because larvae that are born with higher amounts of nutrients probably have an advantage in surviving especially in low sodium environments. (See Molleman et al. 2005 for more information)

But why so many of this species?   Clouded Sulphur caterpillars feed on legumes like alfalfa and clover, and there can be as many as 3 generations in favorable years, so it isn’t surprising to expect to see large numbers of them in agricultural areas in mid to late summer.

But Sulphurs aren’t the only butterflies you might see visiting puddles, many other species of   terrestrial arthropods that have low salt diets including Blattodea, Diptera, Diplopoda, Hemiptera, Hymenoptera and Orthoptera have also been observed to puddle.

References:

Molleman F, Grunsven RHA, Liefting M, Zwaan BJ, and Brakefield PM, 2005. Is male puddling behaviour of tropical butterflies targeted at sodium for nuptial gifts or activity? Biological journal of the linnean society. 86: 345-361   

Smedley and Eisner, 1995. Sodium Uptake by Puddling in a Moth. Science. 270: 1816-1818

May 30 to June 5, 2010: Wild Rivers Legacy Forest by Erin Gnass

One of the many exciting bird research projects that I helped to investigate this summer was with the Nature Conservancy (TNC) in the Wild Rivers Legacy Forest (WRLF) north of Armstrong Creek in northern Wisconsin. With a field crew of eight people, many of us living in one field house, we not only gathered very useful bird survey data for TNC and my graduate thesis project, but we were also fortunate enough to listen to and observe many unique and beautiful bird species. Every afternoon or evening, we met as a group to decide how to break apart all of the required bird survey sites within the forest. Some of us went out in pairs while others surveyed independently to perform as many bird point counts as possible between the half hour prior to dawn until 9:30 AM (the short window of time that breeding birds are allowed to be surveyed). Depending on the terrain, distance between points (via car or on foot), and weather, many pairs or individuals performed as few as 5-6 surveys to as many as 12 in a morning! Therefore, we finished all 200 bird survey sites in the WRLF and the 23 additional sites of poor ecological forest condition in one week’s time!

For some of the bird sighting highlights of this week during the first week of June, we viewed 73 total species within the WRLF including:

16 warblers:  American Redstart, Black-and-white, Blackburnian (in large numbers), Black-throated Blue, Black-throated Green (in large numbers), Canada, Common Yellowthroat, Chestnut-sided, Magnolia, Mourning (in large numbers), Myrtle (the official name of the eastern population of the Yellow-rumped Warbler), Nashville, Northern Parula, Northern Waterthrush, Ovenbird (in large numbers), and Tennessee Warblers

Six flycatchers:  Eastern Kingbird, Eastern Phoebe, Eastern Wood-Pewee (in large numbers), Great Crested, Least (in large numbers), and Yellow-bellied Flycatchers

Six woodpeckers:  in comparison to last year’s data, we observed many more woodpecker individuals:  Downy, Hairy, Northern Flicker, Pileated, Red-bellied, and Yellow-bellied Sapsucker (in large numbers) Woodpeckers

Five thrushes:  American Robin (in large numbers), Hermit Thrush (in large numbers), Swainson’s, Veery, and Wood Thrushes

Four birds of prey:  Broad-winged Hawk, American Kestrel, Barred Owl, and Red-shouldered Hawk

Two vireos:  Red-eyed (in large numbers) and Blue-headed Vireos

And several other birds of interest included:  Black-billed Cuckoo, Black-capped Chickadee (in large numbers), Blue Jay (in large numbers), Brown Creeper, Common Raven, Chimney Swift, Evening Grosbeak, Indigo Bunting, Purple Finch, Rose-breasted Grosbeak (in large numbers), Red-breasted Nuthatch, Scarlet Tanager (in large numbers), White-breasted Nuthatch, White-throated Sparrow (in large numbers), Winter Wren, and Yellow-billed Cuckoo.

In comparison to the 200 sites of the WRLF, we only observed 47 total species within the sites of poor ecological forest condition, including many of those observed within the WRLF. In these additional sites, however, we also observed the Eastern Bluebird, Eastern Meadowlark, Golden-winged Warbler, Ring-necked Pheasant, and Yellow-throated Vireo, which were not observed during point counts in the WRLF.

For fun in the afternoons, we would gather for lunch at a nearby lake, such as Savage Lake, and enjoy the Black Terns, Sandhill Cranes, and Common Loons, which foraged within a few hundred meters of us. Other days we searched for different bird species (e.g. Bobolink) and other walks of life, such as dozens of dragonfly species, as expertly identified by Ron and Joan. We ran into several deer and quite a few black bears, including one close call during a survey that I was conducting by myself. Around minute three of one ten-minute bird point count survey that I was doing, a large black bear peered through thick brush about 25 meters away from me. After shooing it away from me, it still remained close, only about 200 meters away. Upon completing the bird survey and heading back to my car, it stood on its back legs and kept a close watch over me! Thankfully, it continued to forage and stay clear of me.

In one short week’s time, our dedicated and tireless field crew performed many surveys, which provided this study with incredibly useful data that will contribute towards a vastly important conservation project for the future. Luckily, I had some of the most fun that I have ever had working on a bird field crew and am grateful to be a part of this project. Thank you to all of those expert birders on this crew who helped me to become a better birder!

Please take a look at some of the photographs that I took during this week.

TNC's Nick Miller and John Wagner

Lunch break

Dragonfly emerging

TNC John Wagner and volunteer Joan Berkopec with the field crew dog, Pogo

Sandhill Crane foraging along the muddy edge of a lake

Forest road leading to a few of the last bird surveys that I performed just north of Goodman, WI

How NOT to Control Gypsy Moths

Burlap tree wrap.

Burlap "skirt" tied around young oak.

One of the most common ways to try to control gypsy moth (Lymantria dispar) populations is to wrap tree trunks with control bands. These are simply burlap skirts that are wrapped around the tree. Gypsy moths feed on the leaves of the trees at night and then climb back down the tree trunk and hide under the bark or leaves during the day to avoid predators. The burlap skirts provide an ideal hiding spot for the caterpillars and they will congregate there in large numbers. This makes it easy to capture and kill them during the day. The burlap itself does not act as a trap, and actually increases the moth’s chance of surviving to adulthood, because it prevents predators like Blue Jays from seeing them. Burlap only works if the caterpillars are removed every few days. So if you are going to put up the burlap skirts, you must be committed to checking them every few days and killing the caterpillars by squishing them or by scraping them into a jar of soapy water so they drown.

We saw thousands of male gypsy moth flying around burlap skirted oak trees in one of the parks in Green Bay, Wisconsin in July of 2010. There were many females actually laying their eggs underneath the burlap.  This is unfortunate because now there will be more work to remove egg masses this winter and spring.

Burlap lifted revealing gypsy moth pupae.

Burlap lifted revealing gypsy moth pupae.

Some Links on How to properly use burlap tree skirts:

Male (dark) and female (light) gypsy moths with egg masses.

Male (dark) and female (light) gypsy moths with egg masses.

American Bittern

Keen-eyed botanist Gary Fewless spotted this American Bittern (Botaurus lentiginosus) in the Cofrin Arboretum. American Bitterns used to be fairly common in the large marshes on the west side of the Bay of Green Bay, nesting in cattails and in sedge meadows in Atkinson, Sensiba, and Peters marsh. In recent years, as Phragmites australis has invaded and replaced cattails in much of the marshes in northeast Wisconsin, we have seen a decline in the numbers of nesting pairs of American Bitterns.

The loss of large wetland areas to development and degradation by invasive plants like Phragmites and pollutants has taken a toll on bittern populations in the United States. Overall American Bitterns are half as common as they were 40 years ago.

American Bittern

American Bittern at UW Green Bay

This individual is the first to be sighted on the UWGB campus and is probably a young bird that is looking for suitable habitat as it prepares to migrate. According to Richter Museum Curator Tom Erdman, these individuals often return to a location they sampled the previous fall. So perhaps this one might return to nest in the spring.

 
 
 
 

 

Metamorphosis is Tough!

And you thought growing up was tough…try metamorphosis. This unfortunate insect is probably a Spongillafly. It should have long lacy wings (see link for comparison), however, something must have happened as it emerged from its pupae.

When botanist Gary Fewless found this tiny creature, he had no idea just how unique it was.  He found a spongillafly, an insect that is seldom collected as adults. And he found a living individual whose abdomen and wings were highly deformed. 

At least we think it is a spongillafly. We are not completely sure of course, since we are making an identification from a photograph of a badly deformed specimen, but that is entomologist Mike Draney’s best guess, based on the size of the eyes and the pigmentation of the wings. And what exactly is a spongillafly? They are insects in the Order Nueroptera, which also include the more familiar lacewings and ant lions (aka doodlebugs if you’re from the South).  Most Neuropterans are predators. However, spongillaflies are unique, because they are parasites that spend their larval stage underwater feeding on freshwater sponges.  Only 6 species are found in the spongillafly family (Sisyridae) and only 3 of these, Climacia aerolaris, and Sisyra fuscata, and Sisyra vicaria are found in the Great Lakes region.

The adults look similar to brown lacewings. They spend their time flying, feeding and scavenging on other invertebrates, mating and laying eggs on vegetation overhanging streams and lakes usually at dusk or after dark, which is one reason they are so seldom collected.  When the larvae hatch, they fall into the water and float around until the find a sponge. (Wait a minute…there are sponges in Wisconsin?  Well—yes, but we’ll tackle that topic in a later blog. ) The spongillafly larvae use their piercing mouth parts to suck body fluids from the sponge tissues. They don’t kill the sponge and will stay with the same sponge until they are ready to pupate. It is likely our specimen spent its underwater time feeding on its sponge and generally enjoying life.  When it was ready to metamorphose it climbed out of the water, found a site it liked under a rock or tree bark and then spun a silken cocoon around itself for protection. It remained in the cocoon all winter as a hibernating larva, waiting until the warm spring weather to even begin to pupate.  And that is where something went terribly wrong. 

What goes on in the pupa? From our perspective, pupation might seem like a pleasant rest in a bed of silk, this is hardly the case.  Beneath its silken wrap, dropping levels of juvenile hormones trigger a cascade of changes in the developing insect. First, chemical signals are released that signal the epidermal cells to release enzymes that digest the larvae’s cuticle (skin). The cuticle is broken down into and reused to make new parts. Basically the larva is killing its own skin cells.

At the same time special clusters of cells in the body called imaginal discs become active and elongate, using the digested epidermis to  build wings, eyes, antenna, and reproductive parts, as well as the new exoskeleton of the adult insect.  These discs are aligned in pairs and their development is genetically controlled. Any mutation in these genes can result in malformations in the adult, so that a leg might grow where a wing should be.  In fact, it was the study of mutations like these in fruit flies that greatly increased our understanding of how the process and genetic control of early developments occurs.   If anything goes wrong during this period of genetic communication and rapid development the adult will not form properly.

Our insect has all its parts in the right places, so a genetic mutation is unlikely. It is more likely that the pupa was damaged from the outside as it was developing. If the pupa is crushed or bent during this period of radical re-arrangement, the underlying developing adult structures can also be damaged. The developing pupa does not have much capability to repair structures after they have formed.

Damage can also occur after the adult emerges, but before its exoskeleton dries and hardens. The newly emerged insect is soft and its wings are shortened and curled. It must pump fluid from its abdomen into the veins of the wings to enlarge and elongate them.  (See this photo of a newly emerged brown lacewing.  It has nearly finished uncurling its wings.) If the insect falls or is crushed while it is still soft, wings or legs can harden in bent positions. If the abdomen is damaged, internal injuries can result, and the insect will usually die.

Parasites can also cause improper development. Gregarine parasites are protozoa that live in the guts of many different insects including Nueroptera.  The insects are infected by spores that fall onto the eggs as they are being laid.  The spores are eaten by the insect larva and reproduce asexually inside the gut, absorbing nutrients through micropores in their wormlike bodies. During pupation the parasites switch to sexual reproduction, forming spores that are released through the pupal case and dust the body surface adults as they crawl out of the cocoon. They pass the spores onto their offspring when the spores fall onto the eggs as they are laid.  Heavy gregarine infections are known to result in wing deformations in developing butterflies because the butterflies are too weak to hold themselves up or to inflate their wings.

We are not quite sure what went wrong with this individual.   Regardless of what happened to this insect it is unlikely it survived very long after the photo was taken.