Bagrada Bug Integrated Pest Management

1. Bagrada Bug
Integrated Pest Management for Home Gardeners and Landscape Professionals
The Bagrada bug, Bagrada hilaris, also
called the painted bug, is a stink bug
that attacks various vegetable crops,
weedy mustards and several ornamen-tal
plants within the mustard family
(Brassicaceae) such as sweet alyssum,
stock, and candytuft. It is particularly
devastating to young seedlings and
leafy mustard greens (Figure 1).
Bagrada bugs often infest wild mus-tard
weeds, which are pervasive in
California on hillsides and in agricul-tural
corridors in late winter to early
spring. Populations rapidly increase
in the weeds when seasonal tempera-tures
rise. Record numbers of bugs can
invade newly planted cole crops after
mustard weeds dry out in late summer.
The Bagrada bug is an invasive pest
species, native to Africa, which has
spread to India, Pakistan, parts of
Southeast Asia, and Italy. In the United
States, it was first found in Los Angeles
County in 2008. By 2011, the pest had
disseminated throughout Southern
California to include San Diego, Impe-rial,
Orange, Riverside, San Bernardino,
and Ventura counties. In September
2012, the pest moved northward to
Santa Barbara and San Luis Obispo
counties and recently (2013) the Bagra-da
bug was found in Fresno, Tulare,
and Monterey counties. Other states
where this stink bug is currently found
include: Arizona, New Mexico, Nevada,
Utah, and Texas.
IDENTIFICATION
Adult bugs are black with orange and
white markings; the shield-shaped
body is about 1/4 inch (5-7 mm) long
and about half as wide at the broadest
part (Figure 2). Adults may be con-fused
with harlequin bugs (Figure 3),
Murgantia histrionica, but are smaller
at about 1/3 – 1/5 the size. Eggs are
barrel-shaped and deposited singly or
in small clusters of about six (Figure 4).
Eggs are initially white but turn orange
or red prior to hatching. Females lay
eggs in the soil beneath host plants but
may also oviposit on leaves or on hairy
stems of non-host plants. In addition,
eggs are often laid on plant protec-tive
coverings such as mesh screens or
floating row covers. Research suggests
that, depending on temperature and
food source, a female bug can lay up
to 150 eggs within two to three weeks.
Eggs can hatch in as little as four days.
The nymph passes through five instars.
Newly molted nymphs of all stages are
orange-red but legs, head, and thorax
darken quickly to black (Figure 5). The
brightly colored nymphs may be con-fused
with lady beetles but lack their
shiny, hardened wings. Older nymphs
develop dark wing pads and white
spots on the abdomen prior to becom-ing
adults.
LIFE CYCLE
The rate of development and number
of generations per year is dependent
upon climatic conditions and available
food plants. In Southern California,
there are multiple generations each
year and populations generally peak
late in summer and fall. All life stages
may be present together on plants,
especially when pest densities increase,
generations overlap, and food sources
decrease. Even though Bagrada bugs
prefer cool-season cole crops, their
development is favored by warmer
temperatures. Adults tend to fly when
temperatures are above 85oF. Bagrada
bugs may hide in leaf litter or topsoil
during cool periods and cold winter
months.
The Bagrada bug’s main hosts are
plants in the mustard family, and it
requires these host plants for optimal
Figure 1. Bagrada bugs and feeding
damage on mustard greens.
Figure 2. Adult Bagrada bugs are black
with orange and white markings. The
female is larger than the male.
reproduction. This group includes
cruciferous weeds such as various wild
mustards, shepherd’s purse, London
rocket, and pepperweed. Globally, the
Bagrada bug is a serious pest of cole
crops — cultivated plants in the Bras-sica
genus such as cabbage, cauliflower,
broccoli, kale, turnip, and mustard
greens. It also attacks related crucifer-ous
crops such as radish and arugula.
Ornamental landscape plants such
PEST NOTES Publication 74166
Statewide Integrated Pest Management Program January 2014

2. January 2014 Bagrada Bug
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as alyssum, candytuft, nasturtiums,
rockcress, stock, and wallflower can be
infested.
Bagrada bugs may become secondary
pests of other plant families, particu-larly
when densities are high and cru-cifers
are scarce. For example, it infests
weeds such as lambsquarters, purple
nutsedge, Euphorbia spp, perennial
sowthistle, fleabane, and field bind-weed.
It causes feeding damage on the
fruits of bell pepper, melon, papaya,
tomato, and capers. Vegetative and
flowering growth of corn, sudangrass,
sorghum, sunflowers, potato, cotton,
and some legumes, including snap
beans, may also be consumed. The
Bagrada bug forms large clusters on
many different types of plants in the
late summer when pest populations
are high and food is scarce. When
preferred hosts are unavailable, the
bug can be found on plants that are not
reproductive hosts; and it may or may
not attempt to feed. For example, large
numbers of Bagrada bugs have been
found in Ventura County on straw-berry
crops but feeding damage has
not been reported.
DAMAGE
Adults and nymphs of the Bagrada
bug feed on leaves, stems, flowers, and
seeds. They insert their needle-like
mouthparts into plant tissues, inject
digestive enzymes, and suck the juices.
On leaves and stems, starburst-shaped
lesions form. Leaves eventually have
large stippled areas and may wilt and
die. Ultimately damage may result in
“scorched” leaves, stunting, blind ter-minals,
and forked or multiple heads
on cauliflower, broccoli, and cabbage.
Bagrada bugs are particularly damag-ing
to small plants and may kill seed-lings.
MANAGEMENT
Early detection is important because
Bagrada bug populations can build up
quickly. Levels of infestation may be
correlated with proximity to natural
and cultivated areas infested with wild
mustard or to neighboring vegetable
farms. Landscape plants, native plants,
and weeds may need to be monitored
to prevent pest migration. Bagrada
bugs may not be readily observed until
damage has begun, so look carefully
for fresh feeding damage (light green
starburst lesions), which may be easier
to spot than the insects themselves
at early stages of infestation. Home
gardeners and landscapers should care-fully
inspect their plants and shipping
containers prior to planting. A good
time to inspect is right after watering
when pests hiding in the space be-tween
the potting mix and the sides of
the container may be flushed out and
more easily detected.
When the bugs are common on plants,
they may be monitored by beating or
shaking plants over a tray or a sheet
of paper. More frequent scouting may
be necessary when temperatures rise
above 75oF. Bagrada bugs tend to be
most active and visible during the
warmer parts of the day; therefore,
monitoring should occur at those times.
When temperatures are low or on
cloudy days, these bugs may hide on
the undersides of leaves, around stem
bases, or in soil cracks and crevices.
Cultural Control
Remove weed hosts in and near plant-ing
areas. Bagrada bug adults, eggs,
and nymphs in the soil or container
media can be controlled by steam or
chemical treatment before planting.
Removal of plant residue after harvest
can reduce carryover between crops.
In gardens where the Bagrada bug is
present in very high densities, it may
be advisable to remove very attrac-tive
host plants such as sweet alyssum
(Lobularia maritima) and replace them
with plants not in the mustard family.
Sweet alyssum can attract bugs into the
garden and also serve as a source of in-festation
for other plants in the garden
or landscape.
Mechanical Control
Picking the bugs off plants by hand is
only feasible if pest populations are
very low. When infestations are heavy,
it may be possible to vacuum the bugs
with a portable vacuum cleaner. It is
often easier to tap the plant onto a sheet
and collect/vacuum the bugs rather
than removing them individually.
Figure 3. The harlequin bug is orange
and black with no white markings. It
is about ½ inch long--more than three
times larger than Bagrada bug.
Figure 4. Bagrada bug eggs are whitish
when first laid and often in clusters of
several eggs.
Figure 5. Bagrada bug nymphs and
adults. Young nymphs are bright red,
but later begin to develop wing pads.

3. January 2014 Bagrada Bug
Figure 6. Fluon-coated pyramid trap
baited with sweet alyssum and placed
next to a heavily infested mature broc-coli
field. It contained several hundred
adult Bagrada bugs after a 24-hour trap
period.
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Pyramid traps (Figure 6) baited with
crushed sweet alyssum, inside poly-propylene
bags, can also be used to
catch and destroy bugs, particularly
when numbers are high. These traps
are available commercially as stink bug
traps (e.g., Rescue Stink Bug Trap) but
the chemical lures sold to attract other
stink bug species will not work against
the Bagrada bug.
Growers that have access to green-houses
can protect cruciferous bedding
plants and vegetable plugs by produc-ing
them inside. Using a double-door
system in greenhouses can help to
exclude the bugs and screened vents
prevent entry of flying adults. As an
alternative to greenhouses, screened
tunnels or floating row cover fabric
can provide plant protection in gar-dens.
The mesh of the screening mate-rial
must be fine enough to exclude
the Bagrada bug nymphs and should
be elevated so that it does not touch
the plants because the bugs can feed
through these coverings. The edges of
protective covers must also be buried
to prevent the bugs from crawling un-derneath
to the plants, and they must
be applied before Bagrada bugs get into
the crop.
Biological Control
Although spiders and other general
predators may feed on the Bagrada bug,
it does not have specific natural en-emies
in the United States. Stink bugs
are so named because they secrete a
foul-smelling liquid that is repulsive
to many predators. Birds apparently
find the taste of these bugs unpleasant
and may avoid eating them. Several
parasitoids that attack eggs, nymphs,
and adult Bagrada bugs are reported
in the literature; but thus far, effective
biological control organisms have not
been available despite the prevalence of
this pest in many countries. Unlike the
harlequin bug, which it strongly resem-bles,
the Bagrada bug often lays eggs
in the soil, which would render egg
parasitoids, such as wasps, ineffective.
Moreover, although biological control
options are currently being evaluated
by some researchers, Bagrada bug den-sities
can increase rapidly and biologi-cal
control alone will probably not keep
populations in check.
Chemical Control
There is little information on the ef-fectiveness
of pesticides that can be
used against the Bagrada bug in home
gardens. Generally, stink bugs are dif-ficult
to manage with insecticides; and
repeat applications are often necessary.
The adult bugs usually escape injury
by flying away before they contact the
insecticide only to return later. Home
vegetable growers, especially those
growing organic crops are likely to
have better control using covers or
screening to exclude bugs or by simply
removing host plants from the garden.
If insecticides are used, check the pes-ticide
label to make sure the product
is registered for use on home gardens
and landscape plants. Research focused
on managing the pest organically on
commercially grown cole crops sug-gests
that pyrethrum may suppress
adults while azadirachtin and insecti-cidal
soaps may reduce populations of
nymphs.
REFERENCES AND
SUGGESTED READING
Arakelian, G. Bagrada Bug. 2010. Center
for Invasive Species Research. http://
cisr.ucr.edu/bagrada_bug.html.
County of Los Angeles Agricultural
Commisioner/Weights and Measures.
2008. Bagrada Bug (Bagrada hilaris).
http://acwm.lacounty.gov/pdf/Bagrad-abug.
pdf.
County of Santa Barbara Agricultural
Commissioner’s Office. 2012. Bagrada
Bug: A New Pest of Cole Crops and Veg-etable
Gardens in Santa Barbara County.
http://www.countyofsb.org/uploaded-
Files/agcomm/bulletins/Bagrada Bugs
2025SEP2012.pdf.
Dara, S. 2012. Bagrada bug is now in
Santa Barbara County. http://ucanr.
edu/blogs/blogcore/postdetail.
cfm?postnum=8282.
Dara S. 2012. Update on the Bagrada bug
as it moves up to San Luis Obispo County.
http://cesantabarbara.ucdavis.edu/?blo
gpost=8438&blogasset=26598.
Halbert, S. E., J. E. Eger. 2010. Pest Alert:
Bagrada bug (Bagrada hilaris) (Hemip-tera:
Pentatomidae) an Exotic Pest of Cru-ciferae
Established in the Western USA.
Florida Department of Agriculture and
Consumer Services, Division of Plant
Industry. http://www.freshfromflorida.
com/content/download/23898/486239/
bagrada-bug-pest-alert.pdf.
Lawrence, C. 2012. Bagrada bug popula-tion
explodes at organic farms. Ventura
County Star. http://www.vcstar.com/
news/2012/oct/02/bagrada-bug-population-
explodes-at-organic-farms/#
ixzz2K3AnNxEW.
Lazaneo, V. 2012. The Bagrada bug: A
new pest in San Diego County. San Diego
County Master Gardener Newsletter,
September. San Diego County Master
Gardener Association. http://www.
mastergardenerssandiego.org/newslet-ter/
article.php?ID=32.
Natwick, E. T., Palumbo, J. and S. Dara.
2013. Bagrada Bug in Agriculture. UC
IPM Online, Statewide Integrated Pest

4. January 2014 Bagrada Bug
AUTHORS: D. A. Reed and T. M. Perring,
Dept. of Entomology UC Riverside; J. P.
Newman, UC Cooperative Extension, Ventura
and Santa Barbara Counties; J. A. Bethke,
UC Cooperative Extension San Diego and
Riverside Counties; J. N. Kabashima, UC
Cooperative Extension, Orange and Los
Angeles Counties.
TECHNICAL EDITOR: M. L. Flint
EDITOR: K. Beverlin
ILLUSTRATIONS: Figs 1 & 6. D. Reed,
Fig 2. G. Arakelian, Fig 3. J. Clark, Fig 4. J.
Palumbo, Fig 5. S. Dara.
This and other Pest Notes are available at
www.ipm.ucanr.edu.
For more information, contact the University of
California Cooperative Extension office in your
county. See your telephone directory for addresses
and phone numbers, or visit http://ucanr.org/ce.cfm.
University of California scientists and other
qualified professionals have anonymously peer
reviewed this publication for technical accuracy.
The ANR Associate Editor for Pest Management
managed this process.
To simplify information, trade names of products
have been used. No endorsement of named products
is intended, nor is criticism implied of similar products
that are not mentioned.
This material is partially based upon work
supported by the Extension Service, U.S. Department
of Agriculture, under special project Section 3(d),
Integrated Pest Management.
WARNING ON THE USE OF CHEMICALS
Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations
given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed,
away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock.
Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans.
Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens
containing fruits or vegetables ready to be picked.
Do not place containers containing pesticide in the trash or pour pesticides down the sink or toilet. Either use
the pesticide according to the label, or take unwanted pesticides to a Household Hazardous Waste Collection
site. Contact your county agricultural commissioner for additional information on safe container disposal and
for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers
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Produced by UC Statewide
Integrated Pest Management Program
University of California, Davis, CA 95618-7774
Management Program. http://www.
ipm.ucdavis.edu/EXOTIC/bagradabu-ginag.
html.
Palumbo, J. C. and E. T. Natwick. 2010.
The Bagrada bug (Hemiptera: Pentatomi-dae):
A New invasive pest of cole crops
in Arizona and California. Online. Plant
Health Progress doi:10.1094/PHP-2010-
0621-01-BR.
Perring, T. M., Reed, D. A., Palumbo,
J. C., Grasswitz, T., Bundy, C. S., Jones,
W., T. Royer. 2013. National Pest Alert:
Bagrada bug Bagrada hilaris (Burmeister)
Family Pentatomidae. 2012. USDA-NIFA
Regional IPM Centers. http://www.
ncipmc.org/alerts/bagradabug.pdf.
Reed, D. and T. M. Perring. 2012. Bagra-da
Bug (Bagrada hilaris): Serious Invasive
Pest of Cole Crops and Mustard Greens.
http://cisr.ucr.edu/pdf/bagrada-bug-capca-
handout-sept-19-2012.pdf.
Reed, D. and T. M. Perring. 2012. Bagra-da
bug: biology, host range and effects on
cole crops. http://cisr.ucr.edu/pdf/capca-bagrada-
darcy-reed-sept-19-2012.pdf.
Reed, D. and T. M. Perring. 2012. What
are those bugs in the alyssum? Retail
Nursery and Garden Center IPM News.
2(4): 2. http://www.ipm.ucdavis.edu/
PDF/PUBS/retailipmnews.2012.dec.pdf.
Reed, D. A., Palumbo, J. C., Perring,
T. M. and C. May. 2013. Bagrada hilaris
(Hemiptera: Pentatomidae), an invasive
stink bug attacking cole crops in the
southwestern United States. Journal of
Integrated Pest Management. 4(3): DOI:
http://dx.doi.org/10.1603/IPM13007.
Spurrier, J. 2010. Bagrada bug spreads,
threatening winter vegetables. http://
latimesblogs.latimes.com/home_
blog/2010/12/bagrada-bug.html.