"Super Pest" Takes Hold in
A well-established and reproducing population of brown
marmorated stink bugs (BSMB) has
been found in a Midtown Sacramento neighborhood, reported Chuck Ingels, UC Cooperative Extension advisor for Sacramento County.
The infestation seems to be centered around 13th St., south of
Capital Park. This is the first reproducing population in California outside
Los Angeles County.
Ingels said he had no difficulty finding the pests on
tree foliage and flying around when he visited the site last week. The
California Department of Agriculture has designated BMSB a Class B pest.
"This is the worst invasive pest we've ever had
in California, but there is no funding to attempt to eradicate it, nor is there
a mandate to do so," Ingels said.
Brown marmorated stink bug affects many different
crops and is a serious residential problem. It moves around easily, so can be
expected to spread. It can fly up to a half mile at a time and also travels
long distances by hitching rides in vehicles or inside furniture or other
articles when they are moved, often during winter months. As a result, most new
infestations are found in urban areas.
|Brown Marmorated Stink Bug (Photo credit: Baldo Villegas, CDFA)|
Brown marmorated stink bugs are native to China, Japan
and Korea. They were first documented in the in the United States in
Pennsylvania in 2001, but was likely established there several years earlier.
The pest has spread throughout Pennsylvania, is believed to be established in
at least 15 states, and has been found occasionally in more than a dozen
additional states. In 2004, BMSB made its way to Oregon and is now established
in northwest Oregon and a portion of Southern Washington. The National
Agricultural Pest Information System maintains a map showing current infestations, but it does
not yet show California finds. The pest has been present in Los Angeles County
for 6 years.
BMSB feeds on dozens of California crops, including
apples, pears, cherries, peaches, melons, corn, tomatoes, berries and grapes.
Feeding on fruit creates pock marks and distortions that make the fruit
unmarketable. In grapes, berries collapse and rot increases. Wine tasters have
been able to detect stink bug odor in wines made from grapes that had 10 bugs
in a 35-pound lug. It is also a pest of many ornamentals, especially
fruit-bearing trees, princess tree (Paulownia tomentosa), common
Catalpa (Catalpa bignonioides) and tree-of–heaven (Ailanthus
In addition to the damage caused by the BMSB feeding,
the "true bug" can cause disturbing problems for homeowners in the
winter. When the weather cools down, bugs migrate in droves to sheltered areas,
including inside homes and buildings.
|(Photo credit: Baldo Villegas, CDFA)|
"These bugs aggregate in such numbers that there
are reports of people using manure shovels and five-gallon buckets to dispose
of them," Ingels said. "The strong, unpleasant odor the insects emit
when disturbed makes cleanup still more daunting.
BSMB is a pest in its homeland, but is mostly
controlled by parasitic wasps. USDA researchers have collected parasitic wasps
in Asia, but they must be tested extensively before they can be released in
California, a process that will take until 2016.
"Parasitism is our best hope for reducing
populations," Ingels said. "Chemical control of BMSB is very
Ingels said the best way to keep them out of homes is
to exclude them by sealing off any potential entry points, especially around
window air conditioning units. Insecticides that have been shown to be
effective in the lab are often less effective in the field. In and around
the home, insecticides that have efficacy are mostly pyrethroids and
neonicotinoids, both of which can have harmful off-site effects.
Pesticides showing efficacy on farms also include
organophosphates and carbamates. But growers have worked hard to develop
effective Integrated Pest Management programs, and the use of these broad
spectrum sprays will set these programs back. There are also pest resistance
concerns with increasing use of these products.
Control for organic growers and home gardeners will be
most troublesome, and involves the use of row covers, trap crops, pheromone
traps, and predator insects. Ingels is asking growers to be on the lookout for
"Because they are strong fliers, it's just a
matter of time before they reach farms," Ingels said.
The pest can be distinguished from ordinary brown
stink bugs by its larger size, marble-like coloring on its shield and white
markings on the extended edge of the abdomen. BSMB also has distinctive white
bands on the antennae and legs. The UC Integrated Pest Management Program has
posted a video on YouTube to aid in identifying the
Traps with sex pheromones or other attractants can be used to monitor for
the pest, but they are often poor at trapping the bugs even when populations
are high. The best monitoring method is to inspect foliage throughout the year,
and larger branches in late summer and fall for aggregating bugs. A quick
method is to beat foliage over a piece of cardboard or sheet. If suspected BSMB
are found, place some in a container and note where and when they were
collected. Take the sealed container to the county agricultural commissioner or
local UC Cooperative Extension office.
Labels: brown marmorated stink bugS, Super Pest Takes Hold in Sacramento Neighborhood