Please reread, scan this, for the many updates I have made. The Bagradas are now here in force, many plants have been swarmed and already lost, including seedling mustard and radishes. YUK and bummer!
California, Nevada, Arizona, New Mexico, Texas gardeners alert!
Per Wikipedia, Bagrada Bugs are native to much of eastern and southern Africa and parts of southern Europe and Asia. They made a sudden appearance in Los Angeles in June, 2008, its first sighting in the Western Hemisphere. It then moved into the cropland of the heavily agricultural Coachella and Imperial Valleys of California, doing damage to cole crops there, especially those grown organically. As of September 2014 it has reached as far north as San Mateo, Santa Cruz, Merced and Inyo counties, and all California counties to the south except Tulare County.
Although spiders and other general predators may feed on the Bagrada bug, it does not have specific natural enemies in the United States. Birds don’t eat these nasty stink bugs.
The only effective substance, so far, that kills them, is one you have to be licensed to use.
Brassicas are their favorite food, and Brassicas, that’s broccoli, cauliflower, collards, kales, Brussels Sprouts, cabbages, are THE SoCal winter garden plant! Late summer they also infested our tomato and pepper plants.
- Per UC IPM, as an alternative to greenhouses, screened tunnels or floating row cover fabric can provide plant protection in gardens. The mesh of the screening material 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 underneath to the plants, and they must be applied before Bagrada bugs get into the crop and soil.
- What some of the local organic farmers are doing is planting mustards, the Bagrada’s most favorite Brassica, as a trap plant. Giant red mustards give them plenty to munch on. If you find mustard transplants at your nursery, buy them without delay! The Bagradas prefer them, so they go there rather than your brocs. You can also plant radishes, another Brassica, as a trap plant. Don’t harvest them, just let them grow to full size.
Plant your trap plants so they are well up BEFORE you put in your broccoli, cauliflower, collards, kale or cabbage.
If you are planting from seed, immediately securely cover with a floating row cover or the babies will be eaten. Recent seed plantings of giant red mustard and radish have literally been mowed by the bugs. If you can find transplants, get them and do the same, cover immediately with a floating row cover. Once the cover is off, keep a dedicated sunny midday watch and remove any Bagradas. You may save your transplants and your other plants. Or, grow transplants at/in home, away from the pest, then keep a keen watch when you plant them out.
If you are a mustard greens or radish eater, you must plant enough as trap plants plus what you hope for to eat. I highly recommend you plant them in various areas well separated from each other. At the community garden I see patches that have been infested, mowed, and areas that haven’t been touched at all. Hope that’s just not a matter of time until they get those next.
- The big CON of trap plants is they BRING Bagradas! The other alternative is to remove any Cruciferous plants, like mustard types, radish, all Brassicas, until the weather cools. Then, plant whatever you want!
- Mind you, you still have to REMOVE BAGRADAS by whatever means you prefer, or the brocs are next. Bagradas not only move FAST, but are fast growers andreproducers. They make virtual swarms, and when they suck juices from your plant toxicdisease producing stuff gets in your plant. In hot temps, I’ve seen a 1 1/2 foot tall plant go down in 1 to 3 days. White patches start on the leaves, they wilt and the plant dies.
PLEASE Remove infested or diseased leaves immediately. Hold a large bucket lined with a plastic or tightly closeable bag underneath the area you are going to clip. Bagradas instantly drop to the ground the moment you disturb the plant. So you can’t sneak up on them and cover the plant with a plastic bag. The bucket catches them and the leaves. DO NOT lay the leaves or trim on the ground. They lay eggs both on your plant and in the ground. Eggs you might not see hatch quickly, defeating your clipping. Securely tie the clippings and bugs in a plastic bag so they can’t escape, and take them to the TRASH. Do not put them in compost or green waste. Simply moving Bagradas doesn’t work. They fly.
If the infestation is small, in the cool of early morning, while the Bagradas are slow and haven’t had their morning coffee yet, I hold a large tray under an area of the plant, then tap gently, smush the ones that fall onto the tray. Keep doing it in stages until there are no more. Come back in about five minutes and do it again. The ones that fall to the ground quickly go back up the plant. And don’t let the little round black/red instars get away either. They mature quickly and lay more eggs. You could use a bucket of soapy water, but it really isn’t big enough for the size of most plants.
REMOVE MULCH HABITAT from around infested or susceptible plants until the Bagrada season is OVER. They hide out in the mulch, mate like crazy, lay eggs in the ground. They are expert at playing dead, and once you are gone, quite quickly climb back up on the plant. I’ve seen it. Stand very still and wait…sure enough, there they come. That’s your second chance to remove, euphemism for kill, the ones that escape the first round.
- PLANTING TIPS I highly suggest biodiversity, interplanting – that’s mixing it up,eveninterplanting different varieties of the same plant (especially broccoli), rather thanmonoculturing – a row of a single kind of plant. With rows of a single plant, the pest or disease simply goes plant to plant and you lose the whole row. This also stops leafminers (typical on soft leaved chard & beets) from going plant to plant. Slows them way down.
Plant so mature plant leaves don’t touch! Stop the ease of transmission. If you can’t help yourself, and go monoculture, plant too close, clip back, harvest, the between leaves so they don’t touch. More is not always better. Dense plantings can literally starve plants that get root bound, that have less access to a healthy allotment of soil food and soil organisms that tickle their roots. Jammed together leaves are not able to get the sun power they need, so there are smaller leaves and less fruits. Snails successfully hide out; mildew and leaf miners can ruin the crop. There are so many reasons to give your plants ample space to live and breathe.
Unfortunately, Brassicas don’t mingle with mycorrhizae fungi. With other plants the fungi network linking your plants is proven that when one plant gets a disease or pest, it warns the neighbor plant. That plant then boosts its own defenses!
You could wait and plant your Brassicas late, from transplants, in October, when the weather has cooled. Bagradas thrive at sustained temps 85 degrees and above.
Here is the link to some additional really excellent information at UC IPM (Integrated Pest Management) published Jan 2014.
You have choices!
- Persevere, plant and do what you can. Pray for survival.
- Wait until the weather cools, plant late, October works well.
- Mix it up! Plant a few Brassicas/mustard/radishes now, some more later. Succession plantings are a wise gardener technique! If a first planting fails, plant another round when conditions have changed. If both plantings succeed, YES, you have a continuous fresh table supply!
- Don’t plant over winter; rest your soil, or plant soil restoring cover crops!
- Only plant what Bagradas don’t care for and doesn’t attract them for now; plant your Brassicas later when it’s cooler. Greens are super healthy ~ just don’t plant cruciferaes (plants with four-petal flowers/cross) like Mizuna, mustard or turnips. Better not to get those mixed mesclun 6 packs at this time.
Good luck, Dear Gardeners, be fearless and strong!
See the entire September 2014 Newsletter!