Whiteflies

The upside to garden pests and diseases is getting to do a little amateur backyard science. Any excuse to mix up a martini, pull out the microscope and take a close look at things and we’re all over it. This week’s happy hour entomology comes thanks to a infestation of white flies living on the underside of our tree collards.

I believe the specific culprit pictured above is the greenhouse whitefly, Trialeurodes vaporariorum which, despite the name, does not only inhabit greenhouses. Moving the leaf around under the microscope revealed thousands of tiny eggs pictured on the right. These eggs hatch and pass through several stages on the way to the winged adults seen above. At all stages, whiteflies suck sap from the host plant (brassica family members like collards are a favorite) and exude honeydew. Some whitefly species are tended and protected by ants acting like miniature cattle ranchers in return for the sweet, sticky honeydew–yet another remarkable example of symbiosis among nature’s many cycles of interdependence.

Control of our whitefly interlopers was simple: we washed them off with a hose. If we had a huge row of collards we might have had a bigger problem on our hands, but biodiversity in our tiny backyard means that the whiteflys don’t have many other options for feeding. What we could have done better is to have kept a closer eye on our plants. Daily inspection of more sensitive vegetables is always a good idea, but something we’ve been lax about lately. Keeping intensively planted annual vegetable beds close to places of daily activity means being able to stay on top of pest and disease problems. Raised beds we recently installed by the front door are on the path of our early morning amble down to the street to pick up the newspaper. A quick glance is sometimes all that’s need to spot a problem.

Permaculturalist Bill Mollison and David Holmgren suggest conceiving of our living spaces in a series of concentric zones, numbered one through five, with the first zone being our house and kitchen gardens and the outer zones being less cultivated and more wild spaces. Mollison and Holmgren’s zones are easily miniaturized for small urban yards. Trees that don’t need much attention can go towards the back, the chickens a little closer and the vegetables and herbs can benefit from being close at hand.

For additional information on whiteflys see the Colorado State Extension service’s whitefly quick facts.

Bugs Ate My Garden

A letter from one of our readers:

“I just read the article on growing your own food. I have tried this but have had great difficulty with insect damage. I have tried some of the “natural” insecticides but they don’t seem to work very well. Two of the major problems I have are cutworms that snip off seedlings before they can get started, and a plague of small white snails which invade later in summer and devastate everything. I cannot use chemical pesticides due to my wife’s chemical sensitivities (nor would I want to pollute my garden with them). Any suggestions?”

Read the rest of the article at Reality Sandwich

We Grow Houses

The last time a television news crew showed up near our domicile we were living in San Diego for a brief stint in grad school and those dozens of microwave relay trucks that showed up were beaming vital information about the former apartment of Gianni Versace assassin and spree killer Andrew Cunanan. So when we spotted a NBC news truck near the Homegrown Revolution compound we assumed our Los Angeles neighborhood had produced a new celebrity killer.

It turned out instead to be a photo op for the County of Los Angeles Agricultural Commissioner/Weights and Measures who had deployed the truck pictured above to spray pesticide due to an invasion of the oriental Fruit Fly Bactrocera dorsalis. Two traps in the area picked up some specimens of this interloper which can quickly turn a fruit harvest into a maggot infested disaster. The eradication technique used, the “male annihilation technique” or MAT, sounds like something out of radical feminist and Andy Warhol assassin Valerie Solanas’ S.C.U.M. Manifesto. MAT is conducted by spraying hundreds of trees and utility poles in the affected area with a gel-like substance consisting of a male attractant (methyl eugenol) combined with a pesticide called Naled (trade name Dibrom). Male fruit flys seek out the attractant and die leaving a feminist paradise and killing out the species within two generations. According to the California Department of Food and Agriculture the attractant is species-specific and won’t attract beneficial insects such as bees and butterflies. Public information officer Ken Pellman, on the scene to deal with NBC, assured me that I wouldn’t have any trouble unless I “licked the utility poles” and went on to say that the Naled application would prevent larger applications of pesticides should oriental fruit flys establish large populations down the road. Perhaps.

While toxicity concerns are probably more of a problem in broader applications, (Naled is used for mosquito control and sprayed in much greater quantities for that purpose), a breakdown product called dichlorvos can enter the environment and has been linked with cancer in humans. Naled is also highly toxic to bees and butterflies. We’d also note that any pesticide tends to lose effectiveness over time due to natural selection creating creating pesticide resistance. If any of those male fruit flys survive they may end up breeding offspring who can lick those utility poles and come back for more.

Another question to ask is the validity of the oriental fruit fly detection methods. During the last big fly invasion of the Mediterranean fruit fly, which our spokesman described as a “public relations nightmare” due to the aerial spraying campaign, a number of entomologists questioned whether traps were picking up new infestations or just sporadic discoveries of a permanent population. If it’s a permanent population the spraying is merely a kind of pesticide theater meant to make it seem like something is being done. Meanwhile we invite future agricultural catastrophes through our world economy which allows us the luxury of out of season, mediocre fruit year round all the while inviting in exotic pests.

Whether or not Naled poses a toxicity problem for our neighborhood (it certainly poses a health risk for the workers as that inflatable hand demonstrates), we at Homegrown Revolution have a more basic solution–let’s start growing our own fruit here in Los Angeles County again. We could start by replacing useless street plantings with a city-wide orchard for instance. Ultimately global trade is the culprit in this outbreak and we’ll note that several oriental fruit flys were found in traps located near the harbor where all that cheap crap from China comes in for the Wal-marts of our debased country. We noted the lack of local agriculture to Pellman and he remarked that Los Angeles County used to be the wealthiest agricultural county in the United States back in the 1950s. Now he said, “we grow houses”.

Purple Sicilian Cauliflower


The Homegrown Revolution compound’s purple Sicilian cauliflower (Cavolfiore di Sicilia Violetto from Seeds from Italy) from our illegal parkway garden is now ready for the table after four months since planting from seed. Cauliflower needs some attention; it needs to be kept moist and it’s prone to aphids, but the little buggers can be blasted off with a hose fairly easily. While the plant takes up a lot of room and doesn’t yield a lot per square foot, what most folks don’t seem to know is that the leaves of cauliflower and broccoli plants are edible as well, although best when small.

Ultimately if you’ve got the space cauliflower is worth the effort, especially this particular variety, since when it gets down to it, the Man’s cauliflower at the supermarket just does not compare to the rich flavor of our home grown version. And if flavor isn’t enough to convince you to grow your own, cauliflower is one of those plants that demonstrates the groovy world of fractal geometry, where the smallest parts of the plants maintain the geometry of the whole. Take a look at the even more fractal broccoli cauliflower mashup, chou Romanesco.