This week we continue our visits with the insects known as the true bugs. The last episode focused on despicable bed bugs that have made much news lately. We now catch up with the brown marmorated stink bug that will soon make headlines as they seek refuge in homes in late summer and autumn. Three weeks ago while dining outdoors at a local restaurant in Columbia, I was amused to see diners at the next table drop their napkins and recoil from their table in a slight panic. The manager quickly appeared and the couple animatedly pointed to several spider-like creatures running laps around the perimeter of the circular table. I overheard the manager remark that the spider-like marathoners were actually some type of bug that appeared in ever-increasing numbers each summer. He calmed the nervous patrons by sharing that no harm had ever come to diners by way of these peculiar insects. Nonetheless, a table inside was offered and accepted. Sharing a table with entertaining and harmless bugs is always a treat for a bug-guy and the brown marmorated stink bugs put on quite a lunchtime performance.
One speedster named Stinky easily outdistanced the competition and lapped several pokey bugs during the course of my midday repast. As I glanced around the patio, it was easy to see immature stink bugs in high gear on every table. Chairs and the side of the building were equally busy as stink bugs romped about in a haphazard maelstrom of activity. You may recall from a previous episode that the brown marmorated stink bug a native to China, Korea, Taiwan, and Japan and first appeared in the United States in 1996 near Allentown, PA. The brown marmorated stink bug is now found throughout Pennsylvania and in the neighboring states of New Jersey, West Virginia, Delaware, and Maryland. A second wave of colonists has been discovered in Oregon and California. In addition to the states listed above, brown marmorated stink bug has been found in Virginia, Ohio, New York, Mississippi, Tennessee, and Florida. Due to its penchant to hide in sheltered locations to pass the winter, it often invades recreational vehicles and campers. One traveler reported driving hundreds of miles away from a home in Pennsylvania and opening the camper only to find stink bugs ready to disembark in a new state. No doubt, this will enhance the spread of a cagey hitchhiker.
Loss of crops
At a stink bug summit earlier this year in Kearneysville, West Virginia, we heard reports from apple growers who lost significant portions of their harvests to stink bugs in 2009. They were girding for similar problems or worse for this year’s crops and applying maddeningly large volumes of insecticides in an attempt to hold stink bugs at bay. Over the past four decades, fruit growers have made enormous progress reducing the amount of insecticides used in orchards by implementing an approach called integrated pest management (IPM). This approach relies on creating an orchard ecosystem that supports natural enemies that help control the pests of fruit. Pesticides are used only when needed and growers carefully select insecticides that are least disruptive to the ecosystem. Because the brown marmorated stink bug lacks effective natural enemies in this country and due to the fact that it can be so destructive to tree fruits like apples, pears, and peaches, growers are resorting to multiple applications of potent, residual insecticides to deal with this new threat, thereby reversing years of progress made during the heyday of IPM. Last year my colleague Dr. Galen Dively reported large numbers of stink bugs in soybean fields across a broad swath of farms in central and western Maryland. Stink bugs showed up in record numbers in fields of sweet corn this summer. By plunging their sturdy beaks through the husk into tender young kernels of corn, they remove the nutritious contents of the kernels. In some cases, so many kernels are damaged that the ear of corn actually fails to fill out and becomes distorted. Many corn growers will suffer important losses this year at the beaks of the stink bugs.
Ornamental plants like service berry attract the brown marmorated stink bug.
Stink bugs are not just for farmers. Two weeks ago, I visited several community gardens in Columbia. In several plots, hordes of stink bugs lined up on ripening tomatoes, poked holes in the skin, and drained the juicy tissues below leaving tomatoes puckered and pockmarked. Similar injury has been reported on peppers and many other common vegetables. Even more curious is the ability of the stink bug to utilize a wide variety of ornamental trees and shrubs. While attending the stink bug summit, I stepped outside at a break and was greeted by dozens on stink bug nymphs dining on a nearby butterfly bush. In a state park last weekend, I noticed roving bands of adult stink bugs lining the trunks of elm saplings where they removed sap from tissues just beneath the tender bark. What does this all mean? For many viewing this episode, stink bugs in apple orchards in West Virginia or corn fields in Frederick probably seem remote, but each day for the past week, I noticed adult stink bugs at my windows peeking inside. No doubt, these rascals were casing the joint and when this long hot summer finally ends, and it will, stink bugs will seek shelter indoors. Now I am not usually a betting guy, but due to the widespread distribution and record numbers of stink bugs, it is a safe wager that this autumn’s stink bug invasion will be of biblical proportions. We will visit stink bugs again in another episode of Bug of the Week to report on how everyone has fared.
References:
Bug of the Week thanks George Hamilton, Tracey Leskey, Galen Dively, and other members of the Brown Marmorated Stink Bug Working Group for providing the inspiration for this episode. To learn more about this rascal, please visit the following web sites.
http://www.hgic.umd.edu/content/brownstinkbug.cfm
http://www.northeastipm.org/grantsystem/FundedProjects/ViewProject.cfm?projectID=237195
http://ento.psu.edu/extension/factsheets/brown-marmorated-stink-bug