BMSB situation still stinks for N.J. growers
By KEVIN KAUFMAN
NEW BRUNSWICK — The infamous brown marmorated stink bug — the greyish-brown shield shaped prehistoric-looking pest that has cost growers throughout New Jersey millions of dollars in crop loss since being accidentally imported to Allentown, Pa., in the mid 1990s — is back from overwintering.
And this year, it’s early.
A mild winter followed by a dry, unseasonably warm spring have conspired to form an imperfect storm that has awakened stink bugs from their overwintering about three weeks earlier than this past year.
With the BMSB, which has been spotted in 37 states — up from 29 at this time last year — coming out of overwintering earlier than normal, the voracious direct pest with more than 3,000 hosts and no natural predators will get a head start and complete more generations than normal, leading to an overall larger population.
“I don’t like to make predictions but we certainly are set up to have more stink bugs than last season,” said Dean Polk, tree fruit integrated pest management coordinator at the Rutgers New Jersey Agricultural Experiment Station. “If the weather suddenly turns wet and cold in the next few weeks or so, everything will slow down for the BMSB and also crop growth. At this point, we’d all rather have a successful growing season than less stink bugs.”
So if the BMSB is already here, what can be done?
“We may just find ourselves in the midst of a new reality, which is that the stink bug populations are to such an extent that it’s much easier for them to find each other and reproduce and cause damage,” said Rutgers Cooperative Extension Research Project Coordinator II Kristian Holmstrom.
With peach and apple losses both coming in between four and seven percent last year, those growers did better than during 2010’s catastrophic season that saw losses swell to nearly 50 percent in some spots.
That success came from a combination of factors that included grower preparedness in terms of spraying and a cooler, wetter than normal summer that included the deluges of Hurricane Irene and Tropical Storm Lee.
Additionally, New Jersey producers of stone fruit (peaches, plums and cherries) and pome fruit (apples and pears) received relief from the United States Environmental Agency in July in the form of a section 18 exemption to use the neonicotinoid insecticide dinotefuran.
According to Polk, another section 18 exemption has already been submitted and he feels “pretty good” about its renewal. A second section 18 exemption, this one for bifenthrin, is also being sought.
Those pesticides do take care of a large portion of the BMSB population but it has such a wide spectrum that it also takes out any beneficial insects.
It also adds considerable costs to the growers spraying budgets.
Many growers spent two to three times more on pesticides in 2011 than they did in 2010.
They also incurred more than budgeted for labor and fuel costs, which cut into their already shrinking profits.
Clearly, continuing to rely on spraying exempted chemicals is not a sustainable solution for growers.
“We’re not going to spray our way out of this situation,” stated Polk.
The answer will hopefully come in the form of an integrated pest management program. To that end, the USDA-Agricultural Resource Service North Atlantic Area received a $5.7 million federal grant in October.
The grant’s working group, led by Tracy Leskey, a research entomologist at the Appalachian Fruit Research Station in Kearneysville, W.Va., and George Hamilton, chairman of the Rutgers department of entomology, includes a team of team of no less than 70 scientists from ARS sites and institutions of higher education from across the northeast and Mid-Atlantic regions.
Developing a pheromone to lure the BMSB into traps was second on the group’s priority list this winter, behind only “studies of basic BMSB behavior.”
Just recently, the USDA began testing what it refers to as No. 10 — its 10th attempt at combining the correct chemicals to form an aggregation pheromone that attracts both the male and female BMSB.
Once the correct pheromone is perfected, it can be used for monitoring purposes, to show when and where the BMSB is active.
Researchers will be able to create emergence curves, determine population peaks and identify hotspots.
The pest remains to mysterious because researchers can’t monitor it consistently, other than after it’s already wreaked its havoc on crops.
“We’re learning a little bit more each year,” Polk added.
Updated on the BMSB Working Group can be found at www.northeastipm.org/working-groups/bmsb-working-group/. New Jersey-related updates are available at www.njbmsb.blogspot.com.