![\"Gypsy](\"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2020\/07\/gypsy-moth17-1aarz.jpg\")
<\/a><\/p>\nWe all know the Gypsy Moth story; it\u2019s the poster child of Invasive Species.\u00a0 Gypsy moths (Lymantria dispar<\/i>) (Lymantria<\/i>\u00a0comes from a Latin word for \u201cdestroyer\u201d) were imported from Europe to the Boston area in 1868 by French scientist Leopold Trouvelot.\u00a0\u00a0M<\/i>. Trouvelot planned to do a little genetic tinkering to develop a hybrid gypsy moth\/silk moth caterpillar that was hardier than the native silkworms.\u00a0 America\u2019s wild silkworm moths, family Saturniidae, include the spectacular Luna, Cecropia, Polyphemus, and Promethea moths (https:\/\/uwm.edu\/field-station\/giant-silk-moths-family-saturnidae\/<\/a>) along with some lesser-known, smaller species.\u00a0 Their cocoons are rarely unraveled for their silk.\u00a0 Our silkworms are not related to the domestic silk moth (Bombyx mori<\/i>) in the family Bombycidae, and they\u2019re not related to gypsy moths (family Erebidae) either.<\/p>\n Anyway, some of his breeding stock (inevitably) escaped.\u00a0 The first recorded outbreak was in 1889, and gypsy moths now occupy a wedge of the US from New England to the Carolinas to Minnesota (to see a nifty, animated map that only goes to 2007, check out (http:\/\/en.wikipedia.org\/wiki\/Gypsy_moth_in_the_United_States<\/a>) <\/i>.\u00a0 They are considered to occupy about 1\/3 of the area they\u00a0could potentially<\/i>\u00a0expand into, and in the past 150 years they have stripped gazillions of leaves from billions of trees in the territory they\u00a0do<\/i>\u00a0occupy.\u00a0 Gypsy moth caterpillars feed at night on some 500 kinds of plants, and they are considered a major pest of hardwood (deciduous) trees.\u00a0 Adults are short-lived and do not feed.<\/p>\n Caterpillars are bristly (some people suffer skin irritations from contact), with two bulbous tufts of hairs in front, and two more aft.\u00a0 Gypsy moth larvae get around pretty well \u2013 newly-hatched caterpillars use silk to balloon to greener pastures.\u00a0 Caterpillars feed for six weeks, generally in the treetops.\u00a0 The youngest (black) caterpillars chew holes in the middles of leaves, and when they are slightly older they eat the leaf from its edge toward its center.\u00a0 \u201cTeen-age\u201d caterpillars – more colorful, with paired red and blue spots – climb down to the ground to take shelter during daylight hours, returning to the treetops at dusk (during a heavy infestation, they may feed during the day, too).\u00a0 If\/when they have defoliated a tree, they hike overland,\u00a0en masse,<\/i>\u00a0to find another.<\/p>\n Males grow through five\u00a0instars<\/i>\u00a0(an instar is the eating phase between two molting phases) and females have six instars before they look for a place to pupate (which may be on a tree, a porch, a stack of firewood, a travel trailer, etc.).\u00a0 After pupating for two weeks, males emerge before the females so they are lined up when the females emerge, and the wild rumpus begins.\u00a0 Adult females are flightless and are stuck wherever they pupated \u2013 they use pheromones to lure flying males to their perch, and then create an egg case on the same spot.<\/p>\n What\u2019s all the fuss about?\u00a0 It\u2019s estimated that gypsy moths defoliate more than a million acres of forest a year \u2013 sometimes significantly more \u2013 and they consider trees on suburban lawns to be as tasty as those in the woods.\u00a0 And then there\u2019s the \u201cIck Factor.\u201d\u00a0 During a large infestation, roads, patio furniture, and outside walls are thick with the sights and sounds of caterpillars crawling and munching and of frass (caterpillar poop) raining down.<\/p>\n Tell us, BugLady, after 150 years of noshing, are there\u00a0any<\/i>\u00a0trees left in the eastern US\u00a0at all<\/i>?\u00a0 Why yes, Dearies, there are.\u00a0 Ever driven the Mass Turnpike (which is close to gypsy moth Ground Zero)? There are huge forests of large trees, miles and miles of trees (though forest composition may have changed some).\u00a0 For many trees, the defoliation is only a temporary nuisance.\u00a0 A tree\u2019s potential for recovery is based on what percent of its leaves are eaten, on its species and health, on the amount of soil moisture, and on whether this is defoliation number one, two, three, or more.\u00a0 Most\u00a0healthy<\/i>\u00a0trees will survive a couple of consecutive years of 50%-plus defoliations, re-foliating by mid-summer (although re-foliating saps their energy reserves).\u00a0 Stressed or compromised trees may be killed by the next outbreak.<\/p>\n When caterpillar numbers are low (not every year is a BIG year), birds, shrews, mice (there\u2019s a fascinating connection between levels of acorn production, mouse populations, and gypsy moth infestations), chipmunks, raccoons, wasps, ants, flies, fiery searcher beetles\u00a0https:\/\/bugguide.net\/node\/view\/535769<\/a> <\/i>, and weather (very cold winters and roller-coaster springs) are effective caterpillar controls.\u00a0 In outbreak years, flocks of blackbirds and several bacteria, fungi, and viruses have joined the fray.<\/p>\n To these, we have added imported tachinid flies (of previous BOTW fame), whose maggots parasitize the caterpillars.\u00a0 Tachinid flies that were imported to eat the imported gypsy moths, however, have acquired a taste for native caterpillars, especially caterpillars of our large silk moths, whose numbers have dipped.\u00a0 We also wage chemical\/biological warfare on them, in the form of the bacterial pesticide,\u00a0Bacillus thuringiensis<\/a> <\/i>\u00a0<\/i>(Bt), and with chemical pesticides – contact poisons that affect a larva\u2019s digestive tract (and that may damage humans, too).\u00a0 In some parts of Britain, test areas were \u201cflooded\u201d with pheromones to overwhelm the male gypsy moths\u2019 senses and keep them from finding females.<\/p>\n The $64,000 question is \u201cShould<\/i>\u00a0something be done about gypsy moths?\u00a0 The answer seems to depend on whether people see a lot of caterpillars on the landscape or only a few.\u00a0 Eric R. Eaton and Kenn Kaufman, in the\u00a0Field Guide to Insects of North America<\/u>\u00a0state that \u201cProbably more damage has been done by the huge amounts of poisons sprayed on forests in ill-conceived attempts to control the moth.<\/i>\u201d\u00a0 Most control methods are\u00a0not<\/i>\u00a0specific to gypsy moth larvae (to repeat \u2013 MOST CONTROL METHODS ARE NOT SPECIFIC TO GYPSY MOTHS), and the blanket elimination of generations of larvae (collateral damage) affects the predators of the larvae and the predators\u2019 predators and a whole lot of innocent bystanders.\u00a0 The ripples move out, and maybe some ripples fetch up on the shores of insect-impoverished landscapes and barren July 4th<\/sup>\u00a0Butterfly Counts (seems you can\u2019t be a butterfly without being a caterpillar\/larva first).\u00a0 And yet people who go to municipal meetings to question community spray policies are accused of being \u201canti-tree.\u201d<\/p>\n BugFan Naomi shared this personal experience: \u201cI am out for the week in the Driftless area of Wisconsin, where my family has owned a piece of land for 40 years.\u00a0 Our land is a lovely piece of oak savanna but there has been this horrible “bloom” of gypsy moth caterpillars.\u00a0 The trunks of the trees are positively hairy with them, an alarming concentration that is hard to fathom.\u00a0 Just when one could despair that all was lost, we noticed that they were dying on the trunks, head down.\u00a0 They explode into a goo when touched.\u00a0 This turns out to be the work of some fungus they have ingested that is killing them.\u00a0 So although as youngsters they are doing some damage on the lower branches, they are meeting their demise before going to the next stage.\u00a0 Now the trunks are covered with hairy \u2018skeletons\u2019 (what do you call the furry, leggy remains of a caterpillar?).\u201d<\/i><\/p>\n \u201cEmpties,\u201d Naomi, they\u2019re called empties, and one of two agents is at work.\u00a0 One is a\u00a0Nucleopolyhedrovirus<\/a><\/i> <\/i>\u00a0(NPV), a naturally occurring, gypsy-moth-specific virus which causes a \u201cwilt disease\u201d that leaves the critters hanging from tree bark (and which is now used by the US Forest Service under the name of \u201cGypchek\u201d).\u00a0 The other is a gypsy moth-specific fungus called\u00a0Entomophaga maimaiga<\/a><\/i>\u00a0<\/i> (EM).<\/i>\u00a0 According to the\u00a0Midwest Biological Control News<\/i>, EM, a native of Japan (which has its own gypsy moths), was released near Boston in 1910 in an attempt to control outbreaks. Subsequent tests failed to detect residual fungus in the environment, so the experiment was halted. In 1989, analyses of bunches of mysteriously-dead gypsy moth larvae in the Northeast revealed that their deaths had been caused by EM, but where it had been for 65 years is a mystery.<\/p>\n Trees themselves may have a solution.\u00a0 Bill Bryson, in\u00a0A Walk in the Woods<\/u>, offers this story (whose \u201cscience\u201d the BugLady verified with her plant guy).\u00a0 Oak trees that are heavily infested with caterpillars emit a chemical (distress) signal that travels to trees downwind.\u00a0 As a result, the downwind populations of trees produce higher levels of tannins, chemicals that make the leaves unpalatable.\u00a0 To this the BugLady says \u201cWow!\u201d\u00a0 When the BugLady was taking science (and dinosaurs roamed the earth) a list of plant attributes did NOT include the ability to send\/receive\/process\/react to this sort of external stimulus.<\/p>\n The BugLady<\/i><\/p>\n","protected":false},"excerpt":{"rendered":" Howdy, BugFans, The BugLady heard from BugFan Joanne recently, from out of state.\u00a0 Her State Department of Agriculture was doing aerial spraying for gypsy moths, and Joanne was having a Silent Spring moment.\u00a0 \u201cToday it seems remarkably bug free around …<\/p>\n","protected":false},"author":19040,"featured_media":11633,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","uwm_wg_additional_authors":[]},"categories":[8],"tags":[],"class_list":["post-11629","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bug-of-the-week"],"yoast_head":"\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n