Bagrada bug, Bagrada hilaris, is an invasive stink bug spreading through western Arizona and southern California since
2008, causing severe crop, nursery, and landscape losses. Bagrada bugs gather on plants in large groups. In agriculture, Bagrada bug is a pest of cole crops and other mustard family plants. In home gardens it feeds on these same vegetables and on ornamental plants such as sweet alyssum and candytuft.
How to identify Bagrada bug
- EGGS: Laid singly or in small clusters on underside of leaves, stems, or on soil underneath plants. Eggs are initially white and turn orange-red as they get older.
- WINGLESS NYMPHS: Young Bagrada bugs change color from bright orange to red with dark markings as they get older. Newly molted nymphs and adults are also red but quickly darken.
- ADULTS: See photos below.
Similar stink bug
Bagrada bug adults have the same coloring as harlequin bugs, but are smaller, about a quarter to a third the size, with smaller orange markings.
A single female Bagrada bug can lay 10 barrel-shaped eggs per day and as many as 100 eggs over 2 to 3 weeks. Eggs hatch in 5 to 10 days. The young Bagrada bug has 5 growth stages before molting to become an adult. The life cycle lasts 3 to 4 weeks and several generations may occur in a year.
Impact of Bagrada bug on plants
Bagrada bugs use their needlelike mouthparts to pierce and feed on plants and their seeds. Depending on the kind of plant, plant age, and plant part they feed on, damage can include leaf spotting, wilting, stunting, central stem tip death causing multiple branches or crowns, and death of the whole plant. With high numbers of Bagrada bugs, young broccoli and cabbage plants left unprotected for as few as 2 to 3 days can be significantly damaged.
Bagrada bug prefers plants in the mustard family, such as sweet alyssum, broccoli, cabbage, cauliflower, collards, kale, radish, rutabaga, and weeds such as London rocket, shepherd's-purse, and wild mustard. It reportedly also feeds on strawberries, melons, and members of the nightshade (potatoes, peppers), mallow (okra, cotton), legume, and grain families (wheat, corn, sudangrass, millet).
How it spreads
While bugs may move to other areas on their own, do not transport infested plants or produce into new areas.
Monitoring and scouting
Look for adults on the undersides of cotyledons and leaves during the warmer times of the day (near or above 80°F) when the adults are most active. Keep your eyes on the soil underneath plants. Also look for damage on cotyledons and young leaves.
Bagrada bug has caused severe economic damage to early cole crops in Arizona and California. It can be controlled in conventional field vegetable production using pyrethroid, organophosphate, carbamate, or neonicotinoid insecticides. Unfortunately most OMRI-approved pesticides are unable to control Bagrada bug. Microbial pesticides may work in some situations; research is currently in progress.
Fields near these areas may be at risk:
- Grassy areas (including sudangrass)
- Weedy drains
- Weedy areas, especially with mustard family weeds
- River bottoms
- Residential areas with preferred hosts
- Lush desert habitat
Use insecticides with quick-acting contact activity (i.e., bifenthrin, methomyl, and chlorpyrifos) to provide good short-term protection against Bagrada bug feeding on emerging cotyledons, leaves, and transplants. Residual mortality appears to be limited to about 3 days. Use dinotefuran, a neonicotinoid with translaminar leaf penetration, as a foliar spray to get good adult mortality with residual plant protection for up to 5 days. When Bagrada bug numbers are high, pest management programs on cole crops should alternate contact materials (i.e., pyrethroids and organophosphates or carbamates) during stand establishment (cotyledon–2 leaf stage) when the plants are developing rapidly, then use dinotefuran on established plants to provide residual protection.
In high-risk areas, chemigate at emergence. Once irrigation is pulled consider using the following pesticides, rotating among different mode-of-action classes:
|Common name (example trade name)
First detected in Los Angeles in 2008 and the Imperial Valley in 2009, Bagrada bug invaded New Mexico and Nevada in 2010. Native to East Africa, it is a major pest in Africa, Italy, Iran, Iraq, Pakistan, and India, and Sri Lanka. This invasive pest is now found in Kern, Imperial, Orange, Riverside, San Diego, Santa Barbara, San Luis Obispo, and Ventura counties in California and in Yuma, La Paz, Maricopa, and Pinal counties in Arizona and is expected to spread widely.
Report any sightings
If you find a stink bug you suspect is Bagrada bug in a county where it hasn't been reported, place it in a container, carefully note where and when you collected it, and take the sealed container to your county agricultural commissioner or UC Cooperative Extension office.