Invaders of the Month Thumbnail Title Topic Scientific name Month Palmer Amaranth: The Most Obnoxious Noxious Weed in Maryland Palmer amaranth Amaranthus palmeri July 2024 Watch out for Creepers on your Crapemyrtle! Crapemyrtle bark scale, Crapemyrtle Acanthococcus lagerstroemiae, Lagerstroemia indica March 2023 We are legion, we are lanternfly Spotted Lanternfly Lycorma delicatula January 2023 Eat Your Carrots, Just Not This One July 2022 Don’t Jump to Conclusions about Asian Jumpseed July 2022 Unravelling Maryland’s Knotweed Problem, One Psyllid at a Time Knotweed psyllid Aphalara itadori September 2021 Take the Bait…don’t dump it! June 2021 Colossal Catfish Cause Conservation Complications Blue and Flathead Catfish Ictalurus furcatus and Pylodictis olivaris May 2020 Deceptive little buttercup is foe, not friend Lesser Celandine Ficaria verna March 2020 “New Leaf Disease is a Beech” Beech Leaf Disease Litylenchus nematodes February 2020 The visible invisible: impacts of invasive jumping worms Jumping worms Various spp. November 2019 The Sign of the Times are the Vines Vines Various spp. October 2019 Thousand Cankers Disease Reappears in Maryland Thousand Cankers Disease and Walnut twig beetle Geosmithia morbida and Pityophthorus juglandis August 2019 Teaming up to Tackle Two-horned Trapa: A Highly Invasive New Species of Water Chestnut New Water Chestnut Trapa bispinosa July 2019 Pray for the prey of the praying mantis Exotic mantis species Various spp. June 2019 Toil and Trouble: Weed Risk Assessment Weed Risk Assessment Various spp. April 2019 Tiny beetle, giant impact. Khapra beetle Trogoderma granarium March 2019 Invasive Vinca, Rhymes with “Stinka” Common periwinkle and bigleaf periwinkle Vinca minor and Vinca major January 2019 ‘Tis the Season to Fear Holly Non-native Invasive Hollies Ilex spp. December 2018 Safeguarding American Agriculture – One State at a Time USDA Plant Protection and Quarantine (PPQ) Various spp. November 2018 Spotted Lanternfly and Tree of Heaven Spotted Lanternfly and Tree of Heaven Lycorma delicatula and Ailanthus altissima September 2018 Nitrogen Fixer Fixin’ For Trouble Autumn Olive Elaeagnus umbellata August 2018 Stop the Hitchhikers: Clean Your Gear Clean your Gear Various spp. July 2018 Trapped Again? A New Species of Water Chestnut Discovered in the Potomac New Water Chestnut Trapa sp. June 2018 Are invasive plants “bugging” you? Japanese barberry and bush honeysuckle Berberis thumbergii and Lonicera maackii May 2018 The cherry blossoms have arrived! Some good, some bad. Cherries Prunus spp. April 2018 This little piggy went to Maryland? Feral swine, wild boar Sus scrofa March 2018 Not so Heavenly Heavenly bamboo, sacred bamboo, nandina Nandina domestica February 2018 Red Alert: Spotted lanternfly Spotted lanternfly Lycorma delicatula January 2018 Good for what “Ails” you? A gift from Heaven? Agrilus smaragdifrons Agrilus smaragdifrons December 2017 Misgivings over Miscanthus Chinese silver grass Miscanthus sinensis November 2017 Where Have all the “Flowers” Gone? Invasive & Noxious Weeds along Maryland's Interstate Highways Various spp. October 2017 A Wavyleaf Wannabe Small carpetgrass Arthraxon hispidus September 2017 Maryland Oaks Would Rather “See No Weevil” Asiatic oak weevil Cyrtepistomus castaneus August 2017 Not a Professional Scientist? You Can Contribute Regardless! Citizen science Various spp. July 2017 No Pot of Gold at the End of THIS Rainbow! Yellow flag iris Iris pseudacorus June 2017 An Incisive Invader Incised fumewort Corydalis incisa May 2017 Choose Your Viburnums with Care Exotic Viburnums Viburnum spp. April 2017 Sudden Oak Death Could Be Back in Maryland, and You May Have It. Sudden Oak Death Phytophthora spp. January 2017 Invasive Species: They’ve Got “Good Genes” Genetics Various spp. December 2016 Barriers to BSal: Averting the Apocalypse for North American Salamanders BSal Batrachochytrium salamandrivorans November 2016 King of the (Aquatic) Beasts? Lionfish in North America Lionfish Pterois spp. October 2016 The “nom de plume” of plume grass is: EMERGING INVADER Saccharum ravennae Plume grass / Ravennagrass September 2016 Ailanthus’ Achilles Heel: A Poisoned Arrow in a Wilt Fungus Ailanthus wilt Verticillium spp. August 2016 Should Bee-Bee Tree be Avoided? Bee-Bee Tree Tetradium daniellii July 2016 Boaters Beware! Clean your Gear Various spp. June 2016 Shining a Spotlight on Spotted Lanternfly Spotted Lanternfly Lycorma delicatula May 2016 The Gift That Keeps on Giving Emerald Ash Borer Agrilus planipennis April 2016 Wisteria: Criteria for Deliria?! Exotic Wisterias Wisteria sinensis and Wisteria floribunda March 2016 “I’m Back!” Gypsy moth Lymantria dispar February 2016 The Waterwheel… Turning Over North American Wetlands Waterwheel plant Aldrovanda vesiculosa January 2016 Preventing Invaders Preventing Invaders Various spp. December 2015 Lords and Ladies Misbehaving Italian arum Arum italicum November 2015 Porcelainberry Porcelainberry Ampelopsis brevipedunculata October 2015 Exotic Earthworms Exotic Earthworms Various spp. April 2015 Weed Warriors Weed Warriors Various spp. March 2015 White Nose Syndrome White Nose Syndrome Pseudogymnoascus destructans* February 2015 Zebra Mussels Zebra Mussels Dreissena polymorpha January 2015 Thousand Cankers Disease Thousand Cankers Disease Geosmithia morbida December 2014 Bushkiller Bushkiller Cayratia japonica September 2014 Biocontrols for Invasive Plants Biocontrols for Invasive Plants Various spp. January 2014 Spotting the Spotted-Wing Drosophila Spotted-Wing Drosophila Drosophila suzukii October 2013 Zebra Mussel Zebra Mussels Dreissena polymorpha April 2013 Exotic Snails Exotic Snails Various spp. March 2013 Chronic Wasting Disease Chronic Wasting Disease Transmissible spongiform encephalopathy (TSE) January 2013 Classroom Pets and Projects Classroom Pets Various spp. September 2012 Biological Control Agent for Mile-a-Minute Weed Mile-a-Minute Weevil Rhinoncomimus latipes August 2012 Clean Your Gear Aquatic hitchhikers Various spp. July 2012 Boxwood Blight Boxwood Blight Cylindrocladium pseudonaviculatum June 2012 Kudzu Bug Kudzu Bug Megacopta cribraria May 2012 Lesser Celandine Lesser Celandine or Fig Buttercup Ficaria verna April 2012 Types of Weed Control Types of Weed Control Various spp. March 2012 An Unreasonable Facsimile Japanese Angelica Tree Aralia elata January 2012 Murdannia is Murder Marsh dayflower Murdannia keisak October 2011 Castor Oil for What Ails You? Castor Aralia Kalopanax septemlobus September 2011 Where There’s a Wilt, There’s a Way Oak Wilt Ceratocystis fagacerum August 2011 Welcome Biological Control or Dreaded Plant Pest? Rose Rosette Disease Emaravirus sp. July 2011 You Don’t Want a Stake in This! Beefsteak Plant Perilla frutescens June 2011 Save Your Bait, and Keep the Fishing Great Live Bait Various spp. April 2011 A Weapon Against Weeds Goats Capra hircus March 2011 Have you been Bamboo-zled? Exotic Bamboos Various spp. January 2011 If You Have Allergies, Please Don’t Print This! Paper Mulberry Broussonetia papyrifera December 2010 An Unwanted Pine Pest Revisited Tomicus piniperda Pine Shoot Beetle November 2010 “Winter? Moth” Winter Moth Operophtera brumata October 2010 “Curse You, Red Baron!” Cogongrass Imperata cylindrica September 2010 No Comparison Between Apples and … Trifoliate Orange Poncirus trifoliata August 2010 It is Not Holly Leatherleaf Mahonia Mahonia bealei July 2010 Chocolate Vine: Not So Sweet Fiveleaf akebia Akebia quinata June 2010 Feral Cats Felis catus Feral Cats April 2010 Despite the Lycopene, Still a Bad Actor Autumn Olive Elaeagnus umbellata March 2010 A Familiar and Easily Overlooked Intruder Norway Maple Acer platanoides January 2010 Coming Soon to an Ecosystem Near You? Feral Hogs Sus scrofa December 2009 Could Your Pet Be an Invasive Species? Pets Various spp. November 2009 Dem “Yellows” Give Me the Blues Elm Yellows Phytoplasma spp. October 2009 Tied in Knots by Knotweed Japanese knotweed Fallopia japonica September 2009 Beware: The Dog-Strangling Vines! Black and pale swallow-worts Vincetoxicum nigrum and Vincetoxicum rossicum August 2009 What’s Black and White, and Dread All Over? Asian Longhorned Beetle Anoplophora glabripennis July 2009 There’s No Hiding from Hydrilla Hydrilla Hydrilla verticillata June 2009 “But It’s So Beautiful!” Mimosa Albizia julibrissin May 2009 Restoration through Eradication: Neutralizing Nutria in the Chesapeake Bay Nutria Myocastor coypus April 2009 Grass Carp in the Chesapeake Bay: A Watery Gypsy Moth? Grass Carp Ctenopharyngodon idella March 2009 A Bucket-o-Trouble! Bait bucket introductions Various spp. February 2009 Buy It Where You Burn It Firewood Various spp. January 2009 Bark Disease Blitzes Beech Beech Bark Disease Complex Neonectria faginata and Neonectria ditissima December 2008 Not so Anonymous Euonymus Winged Burning Bush Euonymus alatus November 2008 Brown Marmorated Stink Bug Revisited Brown Marmorated Stink Bug Halyomorpha halys October 2008 Savior to Scourge in Only 7 Inches a Day Kudzu Pueraria montana var. lobata August 2008 Use the Wisdom of Socrates to Identify the “Blood of Socrates” Poison hemlock Conium maculatum July 2008 The Moth that Eats a Million Acres Gypsy Moth Lymantria dispar June 2008 Oh No! Not Rock Snot! What Do You Know About Didymo? Didymo or rock snot Didymosphenia geminata May 2008 Blight Takes a Bite Out of American Chestnuts Chestnut Blight Cryphonectria parasitica April 2008 Putting a New Spin on Trout Myxobolus cerebralis Whirling Disease March 2008 Potomac River’s Floating Salad Bar Has No Takers Water Lettuce Pistia stratiotes January 2008 Red Alert for Redbay? Laurel wilt and Redbay ambrosia beetle Raffaelea lauricola and Xyleborus glabratus December 2007 Another Case of Good Bait, Gone Bad Orconectes rusticus Rusty Crayfish November 2007 Chinese Silvergrass Chinese Silvergrass Miscanthus sinensis October 2007 Tree-of-Heaven is Really Stinking Tree-from-Hell Tree of Heaven Ailanthus altissima September 2007 New Invader Waves a Red Flag Wavyleaf basketgrass Oplismenus undulatifolius August 2007 Feeling Crabby? Chinese Mitten Crab Eriocheir sinensis July 2007 Asian Vine Climbs into Maryland Humulus japonicus Japanese Hops June 2007 A Royal Procession in Maryland Princess tree or empress tree Paulownia tomentosa May 2007 Snowstorms in April? Callery Pear Pyrus calleryana April 2007 MSX (Haplosporidium nelsoni) MSX Haplosporidium nelsoni March 2007 To Bee, or Not to Bee (with apologies to William Shakespeare) Varroa Mite Varroa destructor February 2007 The Green Menace Emerald Ash Borer Agrilus planipennis January 2007 Not So Merry Exotic Barberry Japanese Barberry Berberis thunbergii December 2006 Wineberry Wineberry Rubus phoenicolasius September 2006 Coming Soon to a Wetland Near You! Purple Loosestrife Lythrum salicaria July 2006 Everything Is Coming Up Roses Multiflora Rose Rosa multiflora May 2006 New Viburnum Pest Headed South Viburnum leaf beetle Pyrrhalta viburni April 2006 There’s a special providence in the fall of a sparrow House Sparrow Passer domesticus March 2006 Little Green Invaders European green crab Carcinus maenus February 2006 Sirex, You Say! Sirex woodwasp Sirex noctilio January 2006 Japanese Honeysuckle Japanese Honeysuckle Lonicera japonica November 2005 Resident Canada Geese Resident Canada Geese Branta canadensis October 2005 National Effort to Contain Disease Underway Sudden Oak Death Phytophthora ramorum August 2005 A Reed Too Common Phragmites / Common Reed Phragmites australis July 2005 Mute Swan Mute Swan Cygnus olor May 2005 Worst Weed in Maryland? Canada thistle / Creeping thistle Cirsium arvense April 2005 Is a Bird in the Hand Worth Two in the Bush? Amur Honeysuckle, Morrow's Honeysuckle, Tatarian Honeysuckle Lonicera maackii, L. morrowii, and L. tatarica March 2005 Rust on the Queen’s Crown Chrysanthemum White Rust Puccinia horiana November 2004 No Thank You, M‑A‑M! Mile-a-Minute Vine Polygonum perfoliatum October 2004 When is it good to be out of GAS? Giant African Snails Lissachatina fulica September 2004 Porcelainberry Porcelainberry Ampelopsis brevipedunculata July 2004 An Invasive Species Success Story Water Chestnut Trapa natans June 2004 A Pox in the Orchard! Plum Pox Plum pox virus (PPV) May 2004 Public Education Happens in “Iv’y Towers” English Ivy Hedera helix February 2004 From Wreath to Forest Oriental bittersweet Celastrus orbiculatus December 2003 Citizens Urged to Report Pest of Popular Ornamental Shrub Euonymus Leaf Notcher Pryeria sinica November 2003 The Multicolored Asian Lady Beetle: A Mixed Blessing Asian lady beetle Harmonia axyridis October 2003 One of the Fastest-Spreading Forest Weeds Found In 23 States Japanese Stiltgrass Microstegium vimineum September 2003 Omnivorous Insect a Risk to Humans, Animals, and the Nursery Industry Red Imported Fire Ant Solenopsis invicta August 2003 Colonial Medicine Herb Plasters the Woods with Mustard Garlic Mustard Alliaria petiolata May 2003 A Very Serious Menace Giant Hogweed Heracleum mantegazzianum April 2003 Non-Native Insect Threatens Health of Popular and Beneficial Trees Hemlock Woolly Adelgid Adelges tsugae March 2003
