From the mailbag: Fig-eating Kudzu bugs come to college, Megacopta cribraria

 

A small cluster of kudzu bugs feed on a branch near the base of a developing ‘Sicilian Dark’ figs. Image credit: Sam Bahr

 

Highly invasive kudzu can engulf native vegetation and wreak havoc on ecosystems.

Last week we received a report from the University of Maryland’s eagle-eyed horticulturalist, Sam, that ‘Sicilian Dark' figs were supporting a tiny herd of kudzu bugs. The presence of these rascals in College Park was not surprising, as the bug is known from more than a dozen counties in the DMV and in major cities including Baltimore and the District of Columbia. What is surprising is the bug’s use of figs as a source of food. Here is the backstory. This tale begins not with the bug itself, but with one of its favorite host plants, nefarious kudzu, often called ‘the vine that ate the south’. This invasive plant was first introduced to the United States at the Centennial Exposition in Philadelphia in 1876. Selected for its ornamental value, it once adorned the Japanese House in Fairmount Park, PA. Its ability to fix nitrogen, tolerate drought, serve as forage for livestock, and reduce soil erosion made it a popular choice for planting during the Dust Bowl years and its range in the US expanded dramatically. Kudzu cares nothing about blue or red states and it is now found coast to coast and border to border.

Nymphs of kudzu bugs are almost as hairy as the vines of kudzu on which they feed.

In Asia, kudzu serves as one of the favorite hosts for many species of insects, including the nefarious kudzu bug, and careful inspections of imports and lady luck barred entry of this insect to North America. This changed in 2009 when kudzu bug was discovered near Atlanta, Georgia. How it arrived in the US is anyone’s guess, but like its cousin the brown marmorated stink bug, the kudzu bug is a good hitchhiker and it may have arrived as a stowaway in a cargo shipment from its aboriginal home in Asia. In just three years, the bug moved from Georgia to nearby states of Alabama, Florida, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. Some eleven years ago, Dr. Bill Lamp and the intrepid members of his laboratory discovered the bug in patches of kudzu in Anne Arundel, Calvert, Charles, Prince George’s, and St. Mary’s counties in Maryland. 

As a foodie fond of invasive kudzu, some might herald the arrival of the bug as a blessing, but this bug has a darker side. In addition to kudzu, one of Maryland’s most important crops, soybean, is also on the menu. This bug favors several members of the bean family but has been found on several unrelated species in at least eight other plant families. Soybean growers in infested states have reported important losses associated with kudzu bug. This critter has sucking mouthparts that, once inserted into the leaves and stems, pump methodically to rob the soybean of its nutritious sap. The removal of these vital fluids can significantly reduce yields.

Meet kudzu, the vine that ate the south, overrunning a landscape in Maryland. Shiny kudzu bug adults and hairy kudzu bug nymphs dine with gusto on its leaves. Look closely at this small branch on a fig tree. See the bumps. This spring tiny herds of kudzu bugs made a surprise visit to the University of Maryland where they dined on plantings of ornamental figs.

Kudzu bugs are kind of cute.

Like its cousin the brown marmorated stink bug, kudzu bug is a stinky home invader. Stinky, you bet. While collecting kudzu bugs, I learned that it does not take much for these little guys to release their pungent defensive odor. Dramatic pictures from southern states show sides of homes festooned with thousands of kudzu bugs seeking overwintering refuge in the autumn. In nature, winter refuge is usually provided by plant debris in the field or beneath loose bark of trees, however, where human-made structures adjoin soybean fields, prepare for an invasion. After passing the winter in protected locations, adults emerge in spring and move to soybeans and other plants, where they mate and deposit ranks of barrel shaped eggs on the undersides of leaves. Eggs hatch and hairy greenish-yellow nymphs feed on plant sap for several weeks before molting to the adult stage. These adults lay eggs and the cycle is repeated, however, the ensuing adults are the ones that seek overwintering refuge in autumn.  Adding insult to injury, defensive secretions of kudzu bugs can stain fabric, walls, and skin and may cause skin irritations including blisters to sensitive people.

Circling back to the bugs attacking figs, well, kudzu bug has been also been reported on mulberry. And guess what, like mulberry, fig is also a member of the Moraceae plant family. So, perhaps kudzu bug’s arrival on Sicilian Dark figs is not all that strange. In this time of global change and with the advent of global trade over the past several decades, we should be prepared to meet other warm weather visitors from afar like the stinky kudzu bug.   

Acknowledgements

Bug of the Week thanks Sam Bahr for sharing images of kudzu bugs and inspiring this episode. The articles “A New Invasive Species in Maryland: The Biology and Distribution of Kudzu Bug, Megacopta cribraria (Fabricius) (Heteroptera: Plataspidae)” by A. W. Leslie, C. Sargent, W. E. Steiner, Jr., W. O. Lamp, J. M. Swearingen, B. B. Pagac, Jr., G. L. Williams, and M. J. Raupp and “Bean Plataspid: Megacopta cribraria (Fabricius) (Insecta: Hemiptera: Heteroptera: Plataspidae)” by Ashley Poplin and Amanda Hodges provided valuable insights into this pest.  

 

COME ONE, COME ALL TO EXPLORE THE INSECT PETTING ZOO: MARYLAND DAY, SATURDAY APRIL 27, 2024

 

Children of all ages will have a great time at the Maryland Day Insect Petting Zoo.

 

The Spotted lanternfly is a beautiful insect, but a devastating plant pest.

One of the joys of spring is observing the antics of insects and their relatives as they resume their activities outdoors. To celebrate this annual renaissance, the Department of Entomology hosts an award-winning Insect Petting Zoo as part of the Maryland Day Extravaganza at the College Park Campus of the University of Maryland on Saturday, April 27, from 10 am to 3 pm. The Insect Petting Zoo is in the Plant Sciences Building on the ground floor directly across from the Regents Drive parking garage.

This year’s petting zoo will feature an incomparable ensemble of friendly, ferocious, and creepy crawly creatures. A visit to the petting zoo is sure to delight insect aficionados of all ages, and perhaps convert some former haters. This year's spectacle features bugs from around your home and around the world. Giant Lubber locusts straight from the Everglades of Florida will reveal their favorite delicacies and how they defend themselves from being eaten. Vietnamese and Australian walking sticks are true masters of disguise and giant Madagascar hissing cockroaches will blow your mind with their size and agility.

The ferocious looking whip scorpion does not live up to its name.

Watch out for the Whip Scorpion that has a clever trick up its sleeve, or should we say its tail, to thwart attacks by enemies. If you are lucky, you might catch a glimpse of a Black widow spider with a bright red hourglass tattooed on her abdomen, a ferocious Green Tiger beetle hungry for fresh meat, or a Carpenter bee buzzing about its cage. The arts of trickery, mimicry, thanatosis, and other feats of deception and disguise will be revealed by Blue Death Feigning beetles, the European sowbug (roly poly), Darkling beetles (armored stink beetle), and the astonishing African twig mantis. Learn who will see periodical cicadas this year and why the emergence of Broods XIII and XIX this year is epic.  

The Insect Zoo is not just a treat for the eyes. Children of all ages will have the chance to hold and touch (with parental permission of course) a multi-legged millipede from the desert or a hairy Eastern tent caterpillar from a cherry tree. The very brave may even have a chance to hold a giant tarantula. If touching isn’t your thing, then you can listen to the buzzing of a bee or the hissing of a cockroach from Madagascar. Meet face-to-face the number one killer of humans on the planet - dreaded bloodthirsty mosquitoes.

Come to the Insect Petting Zoo at Maryland Day, Saturday April 27 at the University of Maryland, College Park. Travel around the world to meet rocking Vietnamese walking sticks and giant Australian walking sticks pretending to be dead leaves. Amazing Malaysian leaf insects will try to fool you and watch out for the whip scorpion and its smelly surprise. Hold a giant tarantula if you dare and look at, but don’t touch, the black widow spider. Meet the deadliest creature on our planet, blood-thirsty mosquitoes, and pet a friendly, furry Eastern tent caterpillar. Fast moving green tiger beetles will prowl their cage while blue death feigning beetles will be stuck in second gear. Stop by the cicada corner to learn about the epic dual emergence of Broods 13 and 19 periodical cicadas. Learn why carpenter bees make holes in your deck and why iconic honey bees and their kin are imperiled in our rapidly changing world.

Learn about the epic dual appearance of Brood XIII and Brood XIX periodical cicadas.

Curious smells are on the menu as well. Learn what unwelcome house guest has the aroma of cilantro and discover an arachnid with the pungent odor of vinegar. If you are feeling social, investigate the wonders of perhaps our most important social insect, the honey bee. Stop by the invasive species corner and meet dastardly Emerald Ash Borers, the nefarious home invader and crop destroyer Brown Marmorated Stink Bug, and the newcomer in our region, Spotted Lanternfly.

Children can collect insect stickers and the first 600 visitors may take home a Terrapin Lady Beetle to release in their garden to put a beat-down on insect pests lurking there. 

Don’t miss The Swamp - If you enjoy the life aquatic, be sure to stop by The Swamp, also in the Plant Sciences Building, and learn how dragonflies capture their prey and how diving beetles extract oxygen from water.

So, come one, come all to explore Maryland Day and the Insect Petting Zoo!

To learn more about Maryland Day and the location of the Insect Petting Zoo please click on the following links:

Maryland Day:  https://marylandday.umd.edu/  

Insect Petting Zoo and Discover a Swamp, 10am-3pm: https://marylandday.umd.edu/events?neighborhood=ag-day

 Acknowledgements

Bug of the Week thanks Dr. Paula Shrewsbury and her hardy crew of volunteers for organizing and helping out with the Insect Petting Zoo. Thanks also to Dr. Bill Lamp and his students for organizing Discover a Swamp at Maryland Day. Special thanks to Todd Waters for making our arthropods the happiest six and eight-legged creatures on the planet.

From the Bug of the Week mailbag – Be on the lookout for one slowly moving invasive pest: Euonymus leaf notcher, Pryeria sinica

 

Yikes! Euonymus leaf notching caterpillars are on the loose. Credit: Jeremy S.

 

Over two decades followers of Bug of the Week have witnessed tales of exotic, invasive pests like emerald ash borer, brown marmorated stink bug, and spotted lanternfly racing across our country killing trees, pillaging crops, and sometimes invading our homes. Take spotted lanternfly, which, since its discovery in Pennsylvania a mere decade ago has traveled more than 600 miles, or brown marmorated stink bug which spread more than three thousand miles in roughly two decades. As of March 2024, EAB has killed tens of millions of ash trees in 36 US states and the District of Columbia as well as five Canadian provinces, since its discovery in Michigan in 2002. This week we visit another non-native pest. This slow mover has remained more or less bottled-up in Maryland and Virginia for more than 20 years. 

During March and April, hordes of caterpillars strip leaves and create frass fouled foliage (repeat three times fast).

Back in 2002 a new pest was discovered in Fairfax, VA, when a homeowner noticed a voracious caterpillar munching her ornamental euonymus. The caterpillars were sent to Eric Day at the Insect Identification Laboratory in Blacksburg, VA. Eric reared the larvae and sent the unknown moths to specialist John Brown at the Systematic Entomology Laboratory, USDA. Dr. Brown identified the moth as one not known to occur in the US – a new, exotic, invader. The scientific name of this alien is Pryeria sinica. Prior to its discovery in Fairfax, this pest was only known from eastern Russia and China through Korea, Japan, and Taiwan. In 2003 more moths were collected in Northern Virginia and on May 28, 2003, Gaye Williams at the Maryland Department of Agriculture identified specimens of Pryeria sinica from Anne Arundel County, Maryland. Somewhere along the way the new pest was dubbed the euonymus leaf notcher due to the distinctive pattern of feeding caused by the caterpillar. As large caterpillars eat, sections of leaf along the margin disappear down their gullets, hence the name leaf notcher. 

The leaf notcher passes winter as taupe-colored eggs deposited in clusters or 150 or more on pencil-sized twigs near terminals of branches. Eggs hatch in mid-March and early April and tiny caterpillars first feed in tight silken webs spun around unfolded leaves at terminals. As larvae grow, they move to expanded leaves to feed and are often found in large groups. Their presence is easily recognized by marginal notches and coarsely shredded leaves. When abundant, these caterpillars can entirely strip shrubs. After completing development, larvae wander from the plant seeking protected locations to pupate. Large numbers of wandering caterpillars may alarm homeowners, but citizens should remain calm as caterpillars are not known to eat humans or pets. 

In early spring, euonymus leaf notchers hatch from eggs and scores of caterpillars begin to strip the leaves of euonymus. After completing development in spring, caterpillars spin silken cocoons in protected locations. In late October and November, adult moths emerge from very cute pupae, mate, and deposit overwintering eggs on twigs of euonymus.

Adult euonymus leaf-notcher moths fly in autumn and mimic wasps. This one was found less than 10 miles from the Pennsylvania boarder in Hampstead, Maryland. Credit: Charles Krause

In autumn, caterpillars spin cocoons amidst fallen leaves and adult moths appear to fly, mate, and lay eggs on the terminals of euonymus branches. Unlike many moths, euonymus leaf notchers are day fliers. They have unique patterns and colors on their body and wings that make them closely resemble wasps. The fact that they mimic wasps may help them avoid being eaten by day feeding predators such as birds. In North America the leaf notcher has been reported on Euonymus japonicus and E. kiautschovicus ‘Manhattan’. In its native range in Asia, the pest has been reported feeding on E. sieboldianus, E. japonicus, and E. alatus. Moreover, other members of the Celastraceae family such as Celastrus punctatus and C. orbiculatus are recorded as hosts for this pest.

The pest has two obvious weak points that provide excellent opportunities for management. From the time that egg laying ends in December until eggs hatch in spring, eggs can be crushed on the plant or simply removed by pruning off the terminal and disposing of it. If larvae are small or in restricted areas on a plant, then they can also be removed by a gloved hand or pruner. If larvae are widely distributed, abundant, or otherwise difficult to control manually, then several insecticides should perform well. Some of the most “environmentally friendly” insecticides for killing caterpillars contain Bacillus thuringiensis kurstaki (Btk) or the active ingredient called spinosad. Btk destroys cells in the gut of the caterpillar, a slow and painful death to be sure. Spinosad acts on the nervous system of the caterpillar, inducing a more rapid, twitchy form of death. Both insecticides can be purchased as brands that are listed by the Organic Material Review Institute (OMRI) for use in organic food production, which makes them safe enough to be applied to those vegetables and fruits labeled “organic” in your supermarket.  

Euonymus leaf notcher, where are you now? Two excellent sources provide clues to locations where euonymus leaf notcher can be found in the DMV. The Maryland Biodiversity project lists four locations in Maryland with this rascal including Baltimore County, Baltimore City, Prince Georges County, and Anne Arundel County. Carroll County should likely be added to this list as Bug of the Week reported a finding of the leaf-notcher in Carroll County back in November of 2020. A second source of information on locations of the leaf-notcher is iNaturalist which tallies observations in Fairfax and Prince William counties.     

Acknowledgements 

Many thanks to Jeremy S. and Charles Krause for sharing their wonderful images of euonymus leaf notcher and providing the inspiration for this episode. Thanks also to Gaye Williams of the Maryland Department of Agriculture for confirming the identity of the adult moth.

Nature’s other epic event this spring: Periodical cicadas, Magicicada spp.

 

When you see dime-sized holes like these beneath a tree over the next few weeks, you’ve found a place where periodical cicadas will soon emerge. Image: Paula Shrewsbury, PhD

 

Here we are on April 8, 2024, donning special solar eclipse glasses to prevent UV rays from damaging our retinas, preparing to watch the solar eclipse. If, by chance, you miss this eclipse, well, you have to wait another 20 years and a few months to see another one here in the US. But, guess what, there is another amazing natural event taking place in a month that won’t happen again for another 221 years! In a broad swath of southeastern and mid-western states, the simultaneous emergence of two distinct broods of periodical cicadas will delight insect lovers and disturb many others. Earlier this year we broke the news that periodical cicadas would not be seen in Baltimore or Washington, DC, during this emergence. This week, following a deluge of questions from curious folks, we explore when and where periodical cicadas will be seen this year in the US.

Mud tubes and exit holes like these beneath trees are a sure sign you have found a place where cicadas will emerge this spring.

Under some soil conditions, cicadas build mud turrets over their exit holes before emerging from their subterranean nurseries.

When will we see cicadas? Scientists have determined that soil temperatures near 64 degrees Fahrenheit at a depth of about 7 inches signal cicada nymphs that the above-ground world is warm enough for them to emerge from their subterranean crypts, molt into adults, and flee to the treetops where they will find food and mates and, hopefully, escape from hungry beaks and jaws long enough to procreate and lay eggs in small branches. In a series of studies conducted back in 2017 in the DMV, we saw the first cicada emerge on April 19th near Towson, MD. This extreme outlier was the bellwether for the rest of the brood, which appeared full-force during the latter half of May. The two broods emerging this spring are Brood XIII, the Northern Illinois Brood, and Brood XIX, the Great Southern Brood. Brood XIII is an ensemble of three species, M. septendecim, M. cassini, and M. septendecula, that emerge on a 17-year cycle.  Brood XIX is a collection of four species of periodical cicadas, Magicicada neotredecim, M. tredecim, M. tredecassini, and M. tredecula, that emerge on a 13-year cycle. Because Brood XIX is distributed in a broad swath from Maryland to Louisiana, it’s a safe bet that in southern states emergence will occur earlier than in Maryland and cicadas there may make their 2024 debut in late April or early May.

Brood X cicadas appearing one year early in the spring of 2020 provide clues as to when cicadas will appear in 2024 in Maryland and Virginia. The first cicada to emerge was seen on April 19 and the last on June 14. If 2024 is anything like 2020, outliers will appear in April, but the great cicada tsunami hits the last two weeks of May. By Memorial Day weekend the cicadapalooza will be rocking the treetops in 18 states around the country.  Graph: Michael J. Raupp, PhD

This video first aired on April 19, 2021. Watch to see what is happening now in 18 states as periodical cicadas of Broods XIII and XIX get ready to emerge in 2024: "For seventeen years, nymphs of Brood X cicadas have been developing underground. While digging a hole in my yard in 2018, I discovered a quartet of periodical cicadas about 14 inches underground. Notice their white eyes and uniformly tan bodies. Last week, a periodical cicada not quite ready to emerge rested at the top of its exit gallery beneath a cinder block. Just behind its red eyes, the dorsal surface of the cicada is uniformly tan. On the evening of its emergence, notice how the dorsal exoskeleton of the fully developed cicada nymph bears two distinct black patches just behind its eyes."

Where will we see cicadas? Although periodical cicadas will not be seen in Baltimore or the District of Columbia, you won’t have to travel far too commune with these rascals. Southern St. Mary’s County in Maryland will host cicadas, as will several counites and cities in Virginia (see the list below). Historical records report cicadas as close as Alexandria, Stafford, and Williamsburg in Virginia. Cicada Mania, the amazing website for all things cicada, lists these locations as the ones where periodical cicadas will emerge in 2024.

Brood XIII

“Illinois places: Belvidere, Brookfield, Channahon, Chicago, Des Plaines River Trail, Downers Grove, Egermann Woods County Forest Preserve, Elmhurst, Flossmoor, Geneva, Glen Ellyn, Highland Park, Hinsdale, Homewood, La Grange, Lagrange Woods, Lake Forest, Lansing, Lincolnshire, Lisle, Lombard, MacArthur Woods Forest Preserve, Marseilles, McHenry, McKinley Woods, Morton Arboretum, Naperville, Northbrook, Ogden, Ottawa, Palos Heights, River Forest, River Grove, Romeoville, Ryerson Woods, Schiller Park, Thornton, Vernon Hills, Villa Park, Weaton, Western Springs, Westmont, Wonder Lake, and more.

Illinois counties: Bureau, Carroll, Cass, Cook, DuPage, Fulton, Grundy, Henderson, Henry, Jo Daviess, Kankakee, Lake, LaSalle, Livingston, Logan, Marshall, Mason, McHenry, McLean, Menard, Peoria, Putnam, Sangamon, Stark, Tazewell, Whiteside, Will, Winnebago, Woodford.

Iowa places: Atalissa, Solon, and more.

Iowa counties: Benton, Black Hawk, Bremer, Cedar, Dubuque, Henry, Iowa, Johnson, Jones, Linn, Louisa, Muscatine, Scott, Tama.

Wisconsin locations: Aurora University, Big Foot Beach State Park, Lake Geneva, Moraine Nature Preserve, and more.

Wisconsin counties: Crawford, Grant, Green. Rock, Walworth.

Indiana locations: Crown Point, Portage, Purdue-North Central, Valparaiso, and more.

Indiana counties: LaPorte, Porter, Lake.

Michigan: According to Cicadas @ UCONN (formerly Magicicada.org), Magicicada have been found along the border of Michigan and Indiana.”

Brood XIX

Alabama counties: Barbour, Bullock, Butler, Calhoun, Chambers, Choctaw, Clarke, Crenshaw, Elmore, Etowah, Greene, Lawrence, Limestone, Lowndes, Monroe, Montgomery, Russell, Sumter, Tallapoosa, Wilcox

Alabama cities: Huntsville, Lowndesboro, Talladega

Arkansas counties: Boone, Futon, Howard, Izard, Lawrence, Marion, Montgomery, Pike, Scott, Searcy, Sevier, Sharp, Washington, Yell

Georgia counties: Bibb, Bleckley, Butts, Columbia, Elbert, Greene, Harris, Houston, Jasper, McDuffie, Monroe, Muscogee, Oconee, Peach, Pulaski, Putnam, Richmond, Stephens, Taliaferro, Troup, Warren, Wilkes

Georgia cities: LaGrange, Lincolnton, Rome, Washington.

Illinois counties: Adams, Brown, Calhoun, Cass, Champaign, Clark, Clay, Coles, Cumberland, De Witt, Effingham, Fayette, Ford, Franklin, Gallatin, Hamilton, Hancock, Iroquois, Jefferson, Johnson, Marion, Massac, Morgan, Moultrie, Pike, Pope, Saline, Shelby, Vermillion, Washington, Williamson

Illinois cities: Charleston, Decatur

Kentucky counties: Allen, Caldwell, Christian, Trigg

Louisiana parishes: Caddo, Claiborne, Madison, Morehouse, Ouachita, Washington, Webster. Parish information comes from older literature, and might not be as accurate as recent information.

Maryland counties: St. Mary’s

Missouri counties: Adair, Boone, Callaway, Carter, Clark, Cooper, Dent, iron, Jackson, Knox, Louis, Lincoln, Macon, Maries, Marion, Montgomery, Morgan, Oregon, Osage, Pettis, Phelps, Ralls, Reynolds, St. Charles, St Francois, St Louis

Missouri cities: Columbia, Gerald, Manchester, Pevely, Poplar Bluff, St. Louis, Troy

Mississippi counties: Kemper, Newton

North Carolina counties: Buncombe, Cabarrus, Chatham, Davidson, Davie, Durham, Gaston, Guilford, Mecklenburg, Montgomery, Orange, Randolph, Rowan, Stanly, Union, Wake

North Carolina cities: Apex, Baldwin Township, Chapel Hill, Charlotte, Durham, Harrisburg, Mebane, New Hill, Pittsboro, Raleigh, Waxhaw

Oklahoma counties: McCurtain

South Carolina counties: Abbeville, Aiken, Anderson, Cherokee, Chester, Edgefield, Greenwood, Lancaster, Lexington, McCormick, Newberry, Oconee, Saluda, Union, York

South Carolina cities: Chester, Little Mountain, Rock Hill, Saluda, Winnsboro

Tennessee counties: Blount, Cheatham, Clay, Davidson, Grundy, Hamilton, Jackson, Loudon, Macon, Marion, McMinn, Meigs, Putnam, Rutherford, Sequatchie, Smith, Stewart, Summer

Tennessee cities: Gallatin, Lebanon, Nashville, Spring Hill

Virginia counties: Caroline, Gloucester, Halifax, James City, King and Queen, King William, Middlesex, New Kent, York

Virginia cities: Alexandria, Stafford, Williamsburg

If you don’t live in an area where cicadas may emerge, maybe you can plan a trip to visit these amazing creatures. If you don’t like hordes of large, noisy insects and you live in one of the areas listed above, well, it may be time to plan a vacation to the west coast. For cicada-philes, you can keep up with when and where cicadas are emerging by visiting the Cicada Mania website and participate in the incredible citizen-science project with the free Cicada Safari app. Another great source of information on periodical cicadas is the University of Connecticut’s periodical cicada information pages. Bug of the Week hopes you have a chance to enjoy the dual emergence of periodical cicadas this spring. If you don’t have a chance, don’t lament, Brood XIV returns for a limited engagement in parts of our region in 2025 and Brood II will put on a big show in 2030. Oh, and to watch cicadas, you won’t need special glasses, but you might want some ear protection. When the big boy band cranks it up, their racket will be really loud.

Acknowledgments

We thank Chris Carroll and Seth Borenstein for inspiring this episode. References used for this story include “The periodical cicada” by C. L. Marlatt,  “Reproductive character displacement and speciation in periodical cicadas, with description of a new species, 13-year Magicicada neotredecim” by D. C. Marshall and J. R. Cooley, “Advances in the Evolution and Ecology of 13- and 17-Year Periodical Cicadas” by  Chris Simon, John R. Cooley, Richard Karban, and Teiji Sota, and “Combining Data from Citizen Scientists and Weather Stations to Define Emergence of Periodical Cicadas, Magicicada Davis spp. (Hemiptera: Cicadidae” by M.J. Raupp,  C. Sargent, N. Harding and G. Kritsky.

Why are males first to emerge for mason bees? Osmia spp.

 

A newly minted horn-faced mason bee prepares to take her first flight. Golden hairs called scopa line her abdomen. These will be festooned with pollen when she returns to her gallery to make pollen cakes for her young.

 

Cardboard tubes and drilled firewood make suitable accommodations for mason bees.

Our saga of insects active in early spring continues this week, following previous episodes featuring home invaders like stink bugs and boxelder bugs, and charismatic plasterer bees. This week we pay homage to another group of bees that help keep the plant world humming. A few weeks ago, on March 7, male horn-faced mason bees débuted after spending a chilly winter in their galleries. In nature, mason bees exploit galleries made in trees by other insects, like wood-boring beetles, as nesting sites for their young. To enjoy these pollinators on a more regular basis, several years ago I established a colony of mason bees by purchasing about 30 hollow cardboard tubes from a purveyor of bee paraphernalia. These tubes were rapidly colonized by grateful hordes of mason bees. Each year I have augmented my colony by drilling dozens of small holes in unused splits of maple and oak firewood. The bees have happily obliged by filling every gallery until my colony now numbers nearly a thousand bees.

In the wild, mason bees use galleries in trunks of dead trees as homes for their brood. Watch as these mason bees check old beetle emergence holes in a standing dead tree.

Male mason bees emerge before females each season in a phenomenon known as protandry.

Last spring mason bees filled brood chambers with pollen and eggs and sealed these chambers with mud (hence the name mason bee). The earthen plug keeps out predators and parasitoids intent on feasting on larval mason bees. During last spring, summer, and autumn, bee larvae developed within the galleries dining on pollen cakes designed by their industrious mothers. Over the past few weeks, as the morning sunshine warmed the tubes and logs, earthen plugs were dismantled as fresh new bees set themselves free from juvenile confinement. Like many of members of the insect clan, male mason bees complete development and emerge several days in advance of their future mates. This phenomenon, called protandry, is relatively common in the insect world, as noted by Charles Darwin in his famous work, "The Descent of Man." Throughout the realm of insects, female mason bees are held in high esteem and finding just the right mate is a high priority in the mating game. Apparently, males that emerge early in the season have more opportunity to find and secure mates. Males that are slow to develop and emerge late may find all of the available ladies taken by earlier suitors. These latecomers may ultimately lose in the bee mating game.

After breaking through the earthen plug, a male horn-faced mason bee tidies up before searching for a mate.

For several days, newly emerged male mason bees swarmed around my colony, and I was not surprised to see one of the first females of the season quickly captured, mated, and guarded by an eager male bee.

To prevent interlopers from mating with a female, males guard their mates long after mating is complete.

Mason bees are solitary bees, meaning they lack the well-known social structure of honey bees where a queen mother rules the colony. In the world of mason bees, every female is a queen tasked with providing food for her own daughters and sons. Mason bees provide the valuable ecosystem service of pollination. High on their list of favored plants are some of my favorites as well, apples, cherries, blueberries, and almonds. In a fascinating study Drs. MacIvor, Cabral, and Packer found that in addition to insect pollinated plants, some Canadian mason bees collected significant pollen from wind-pollinated trees, including oaks and birches, and also from the ubiquitous lawn weed, white clover. Upon returning to the cardboard tubes or wooden galleries, females turn pollen and nectar into pollen cakes, the source of food for their bee babies.

Watch as busy blue orchard mason bees and horned faced mason bees enter galleries head first, then emerge, pirouette, and back into their gallery. Is this how they add pollen from their abdomen to the pollen cake?

Glorious yellow pollen cakes line each cardboard tube and gallery.

Provisioning the brood galleries involves an interesting mason bee dance. Returning from a flower, the mother bee enters the gallery head first. She then backs out of the gallery rear-end first and pirouettes 180 degrees, reentering the gallery backwards. After transferring pollen from the hairs on her body to the pollen cake, she departs to search for another load of nectar and pollen. Before each cake is sealed in a chamber, the female mason bee deposits an egg on it. Eggs hatch into tiny bee larvae that consume the cake as they develop and grow throughout the summer and fall. After completing development during autumn, they hunker down for winter, and are ready to emerge just in time for the return of spring and the blossoms of flowering plants. Like many other bees we have met in Bug of the Week, mason bees are gentle and not at all interested in stinging humans. I handled several adults and received a couple of cautionary bites, but never a sting. Nesting materials for mason bees can be purchased commercially and I highly recommend creating habitats for these industrious and fascinating pollinators.

Mason bee babies eat nutritious pollen cakes fashioned by their mothers.

Acknowledgements

References for this episode included “Bee Pollination in Agricultural Ecosystems” edited by Rosalind James and Theresa L. Pitts-Singer, “The significance of protandry in social Hymenoptera” by M. G. Bulmer, “Pollen specialization by solitary bees in an urban landscape” by J. S. MacIvor, J. M. Cabral, and L. Packer, and “The Descent of Man” by Charles Darwin.