Despite the African Bagrada bug’s scientific name, Bagrada hilaris, there isn’t anything funny about this garden pest. These painted stinkbugs arrived in Los Angeles in 2008 and now they are found throughout the western states.
Bagrada bugs travel in large groups and they love to eat plants in the mustard family (Brassiceae). This includes your cabbage, broccoli, cauliflower, arugula, turnips, kale, rutabaga, collards, radish and sweet alyssum. They are also known to eat strawberries, potatoes, peppers, melons, tomato, capers, papaya, okra, peas, beans, wheat, corn, soy, millet, stock, nasturtiums, wallflowers and candytuft. This pest has few natural enemies, being new on the scene and they can cause considerable damage in the garden. Because they can fly, pesticides generally do not work. Bugs simply fly away until the chemicals have diffused and then return to feed. Also, commercial stinkbug bait does not work on Bagrada bugs - their pheromones are different. Insecticidal soaps have been found to be only marginally effective against nymphs. With all of our Californian wild mustard, shepherd’s purse, London rocket, and pepperweed, Bagrada bugs are going to become a serious pest in short order.
Bagrada bug identification
Bagrada bugs look like miniature Harlequin bugs. They are only 1/4” long, with a black, shield-shaped body. They have distinctive white and orange markings (see photo). Females are larger than males.
Bagrada bug damage
Bagrada bugs suck sap from new leaves, stems, seed, and flowers, and damage growing tips (meristem tissue) with needlelike mouthparts. Starburst-shaped lesions can be seen on leaves and stems. Bagrada bug feeding can cause leaf spotting, stippling, wilting, small white areas on leaf tips, and prevents broccoli and other head crops from forming. Severe infestations will kill the plant. When the Bagrada bug first hit southern California, broccoli and cauliflower farmers saw 70% of their crops become unmarketable due to Bagrada bugs.
Bagrada bug lifecycle
Our native stinkbugs lay eggs on the underside of leaves, where they are vulnerable to parasitic wasps. The African Bagrada bug lays its eggs in the soil, near food plants, where it is safe from parasitization. A female Bagrada bug can lay as many as 150 eggs in 2 weeks. Eggs are laid singly or in clusters, on or near host and non-host plants, and on mesh and row covers. The eggs start out white and turn orangish-red as they approach maturity. Wingless nymphs are bright orange when they hatch, turning red with dark marking as they mature. These nymphs outgrow and shed old exoskeletons, in a process called molting, in five different stages, called instars, before reaching adult size. The nymphs are often mistaken for lady beetles, but they lack the shiny hardened shell. Bagrada bugs overwinter in soil and leaf littler.
Monitoring for bagrada bugs
As quickly as populations of this pest grow, it is important to monitor susceptible plants every 2 or 3 days. Bagrada bugs should be removed and destroyed as soon as they are seen. These pests are most active when temperatures are above 75° F, so afternoons are a good time to go on a Bagrada hunt. If an infestation is found, you can place a sheet of cardboard or tarp under the plant and give it a good shake. The majority of the bugs will fall onto the barrier, where they are collected and dropped into soapy water to drown. Shop vacs work, too, but you’ll want to make sure you really clean it out when you’re done! Severe infestations should be reported to your local County Extension Office.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.