The brown marmorated stink bug has made itself Maryland’s least welcome invader of 2010. Fat from feasting on orchard and soybean crops, flocks of the Asian alien have invaded homes and gardens, causing more than a foul odor.
“The populations this year have been astronomical when compared with years past,” says Dr. Joe Fiola, specialist in viticulture and small fruit for the University of Maryland Extension. “Multiple bugs per fruit, whereas with green stink bugs [the garden variety] you would see one or two to a tree.”
These invaders come with a ravenous appetite.
“They have multiple generations, and from the youngest to the oldest, they feed,” says Fiola. “Typical stink bugs only feed as adults. So it’s constant pressure on the crops.”
The Maryland Department of Agriculture began receiving distress calls from orchardists and soybean growers inundated by the brown bugs. These brown marmorated stink bugs dine mostly on fruit and crops, which has made them a threat to Asian agriculture for years.
With no natural enemies in the Maryland ecosystem, these stink bugs force growers to use pesticides instead of the more ecologically sound IPM — Integrated Pest Management — system recommended by the University of Maryland Extension.
“We spent many years trying to develop an IPM program that promotes natural predators,” says Fiola. “When you spray an insecticide, it disrupts that natural balance. You eliminate the desirable bugs with the undesirable bugs. We might see outbreaks of scale insects and mites, which are normally not a problem because of IPM.”
Now the bugs are flying into our homes.
“There are just loads and loads of them,” Fiola says. “You look on the side of our building right now and there are hundreds if not thousands.”
When they invade your house, “Kill them,” Fiola recommends. If the smell is a deterrent, then follow Fiola’s home system: “I have an empty water bottle and I just knock them in there. You can fill the bottle pretty quickly.”
For larger home infestations, shop-vacuuming the bugs works, but be sure to empty the container. When the bugs find they can’t get out of the vacuum they become stressed — and release their noxious odor.
Either way, you may want to find a deterrence system now, before the cold sets in. Then, these brown stinkers flood into homes in even larger numbers, which means you may have to find a contingency plan for uninvited house guests.
Because this invasive species is a new problem in Maryland — with the first reported sighting in Pennsylvania around 2001 — the Maryland Department of Agriculture isn’t ready to break out a statewide pesticide program. But Fiola and his team are already testing grape crops for bug infestations.
“We’re trying to come up with a threshold, to tell growers how many insects they can tolerate in a hull of fruit,” says Fiola. “Up to five bugs in 25 pounds of fruit, and you can smell it. We’re telling growers how stringent they need to be when they sort their fruit before they throw it in the crusher.”
In the garden, your first line of defense should be a talk with the University of Maryland Extension’s Home and Garden Information Center, where experienced master gardeners and agricultural experts can advise you on how to find relief without sacrificing vegetation. Your second line of defense: Invest in a lot of empty water bottles.