There’s a New Bug In Town

There’s a New Bug In Town

Home gardeners and farmers alike in our area have experienced a new kind of pest in the past few months, an unwanted import from Africa called the bagrada bug. This pest resembles a lady bug if you don’t have your glasses on, or even our old friend the “stink bug.” The bagrada bug is about the size of a watermelon seed or a lady bug and has orange and white markings on an otherwise mostly black, shield-shaped body. Unlike a lady bug, the bagrada has piercing and sucking mouth parts to feed on plants that leave dead spots, can stunt the growth of a plant, and will eventually kill the plant.

The bagrada first appeared in San Diego county about six years ago and has been moving steadily northward and eastward since. Scientists and farmers had hoped that freezing temperatures would limit its numbers, but now have learned that the bagrada burrows into the soil and waits for warmer temperatures before becoming active again. It can still be seen during milder winter temperatures along the central coast but they’re not eating. Loitering might be a better way to describe them this time of year.

The Bagrada Bug Poses Serious Threat to Small Farms and Gardens
06_bagrada_bug_cisr-1Steve Jones of Bar-D Ranch near the Elkhorn Slough reports that the “entire area” all the way from the hills to the coast are infested. “The good news is they don’t eat everything,” Jones said recently. “We grow a number of different crops and we use a row cover (netting) to keep them from eating our crops.If you’re growing a lot of different things, you’ll be okay. But if you’re only growing arugula, you’re in trouble.”

Jones said they removed the bugs by hand for a period but that was not a very practical method. “You can see them in the weeds” he said, “and when the weather warms up they move into the crops.”

Ronald Donkervoort of Windmill Farm learned about the pest the hard way. “I planted a half acre of kale and everything was going well, and then one day the entire crop was gone, almost overnight.” After doing some research he replanted his kale a few weeks later, but this time he covered the crop with row net, the same as Bar-D Ranch. “The row net kept the bagrada out. The bugs could get to some of the outer leaves but that was it. The kale did well with the netting around it.” Next year Donkervoort plans to use “crop traps” such as bok choy and arugula to attract the bagrada and keep them away from his other crops. Once the bagrada are happily eating away, the trap crop is destroyed using a roofing torch, eliminating the pest.

Pest Management for Gardens and Landscapes
The bagrada seems to prefer cruciferous vegetables such as kale, cabbage, cauliflower, Brussels sprouts and broccoli, but aren’t all that picky if those crops are not around. The University of California Agricultural Extension provides regular updates as to the insects progress. This pest poses a serious threat to small farms and home gardeners, so keeping appraised of the latest treatment options is crucial to slowing its spread. Their population can skyrocket if unchecked, making any type of gardening a futile effort.

If you’re a home gardener, weed management is paramount. Bagrada bugs love weeds, but appear to have a super power at finding cruciferous vegetable seeds. So before planting, make sure the area both in your garden and around it are clear of all weedy material. There are a number of organic pest control products that have been shown to be effective at keeping the bagrada from destroying your plants.

For more information on bagrada bug control using organic methods, see these sites:
http://www.ipm.ucdavis.edu/pestalert/pabagradabug.html
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=14915  
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=11632
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=11591
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74166.html

Photos used with permission. Photos by Gevork Arakelian, Senior Biologist, Los Angeles County Agricultural Commissioner/Weights & Measures Department.