Ladybug vs. Aphid

I don't know much about Alien vs. Predator, except that it involves two species having a war on Earth. One side does vanquish the other, but the human interests caught in between are also almost completely destroyed.

Our own garden's recent battle, that of Ladybug vs. Aphid, has had a similar outcome. While the ladybugs have clearly risen to the occasion to overpower the aphids, there have been casualties. If they just hadn't spent so much time toying with their prey! As you can see from the photos, one whole section of our Fava Beans were rescued. Unfortunately the other section has some major damage. In the first section most plants have been relatively successful, achieving a reasonable height of ~5' and setting plenty of pods. In the other section none of the flowers survived to set pods, all having been destroyed by aphids. What is more, individual plants and some whole areas gave up entirely, not even giving us the benefit of any appreciable biomass!
It is always a learning experience when one watches a crop through its entire life-cycle, and pays attention to how that crop deals with adversity. Certainly when they are flatted and transplanted we always choose the strongest seed and seedlings. After that there is little we can do to help - the plants must continue by their own wits. But by observation there are many lessons to be learned.
These two sections are 200 and 140 square feet, respectively. We plant out many beds of Fava Beans as compost/cover crops in September, but only leave a part of that to go to full maturity. They do a considerable amount of growing before the cold of Winter slows them down, and so we trellis them with stakes and string. Why? This photo explains.
When frost and snow hit them, they lose all turgidity and wilt this way and that. Holding them off the ground preserves the plant when warmth comes again, allowing them the best chance of recovery. Then, once the Spring comes and they leap forth, the trellis keeps them out of the path.
Back to the point of adversity, we noticed that the 200 sq ft section (the one that now looks great) grew more quickly in the Fall, then suffered the most during the frosts. In the Spring it looked terrible, with sections of plants dying throughout. It had aphids as bad as any other section. But now it looks productive and healthy, and will probably have excellent yields. The 140 sq ft section, planted 10 days later, was slower off the blocks, not knocked back as hard by the frost, and then infested with aphids same as the rest. Somehow, though, this section was overcome, set no seed, and areas died before the middle of May.
How do you read this riddle? We know there are no easy answers, and certainly no concrete formulas for success in this kind of matter. In agriculture you watch, pay attention to any variables you can discern, and speculate. For instance, in this case the only constant was the seed source. The losing bed is ten feet from the windward garden border, the healthier bed is well to the center. Maybe the former got too dry at a pivotal moment? What was planted in each bed previously? Did two different people plant the sections with significantly different techniques or attitudes? Did the frost trigger some immune response, or had the bigger plants set more energy aside in the Fall? Did the ladybugs colonize the 200 sq ft section first, or did the aphid infestation really initiate in the 140 sq ft section and spread from there?
So we draw our own conclusions and create theories, then watch in future years to apply them. This is how, after forty years of experience, a farmer can say in the Spring "I think this is going to be a good year for corn, but the cucumbers might be a waste of time."
For the time being, we have an abundance of ladybugs and their spawn, even on the dead plants. In the photo below you can see three stages; larvae, pupae, and adults. Incidentally, I have noticed that there are many adult ladybugs with deformities in their shells and wings. Is this perhaps because eggs were laid in an environment once populated with food, which became scarce by the time the eggs hatched? I can imagine the larvae not getting enough nutrition before transforming, then suffering the consequences as adults. Probably similar in humans...
Look forward to the next post: Purslane Cake!

Integrated Pest Management, Golden Rule Style

Our Fava Beans aren't looking so hot right now. They are suffering, as they always do this time of year, from one of the biblical plagues so hideous it could only be referred to euphemistically as "locusts". Yes, I'm talking about Aphids.

Ours are black, and a little bit of research has me guessing that they are Aphis fabae, the Black Bean Aphid. They are the scourge of our Favas, and probably indicate something of which we should be aware (we are generally of the belief that most plants in any given crop will have pests or disease, but only the weaker specimens will succumb to the attack).

At any rate, we worry some about our beloved Fava Beans, high biomass producers that they are, and heralds of the coming of the Fava Bean Burger mentioned in an older post. Mostly, though, we worry about what other people will think when they visit the garden. So we kind of rush them past the Fava beds.
Until recently, of course, when we began to see the textbook example of what we preach in terms of pest management: Lay off the poisons, focus on a healthy system, then let natural predators step in. Most notably we have the Ladybug, which is our garden hero due to its status as a general predator. Once it has finished with the aphids, it will move on to other pests. Or, more likely, when it has eventually reproduced to levels too large to be sustained on the aphids the excess will migrate to the rest of the garden. So when the plants die (of natural deaths) in June or early July, we will have a ridiculous number of ladybugs spreading out for new grounds. A side-note here; Ladybug beetles and larvae both do plenty of eating, up to 50 aphids a day. And Recently a Dutch group called the Foundation Against Senseless Violence chose the Ladybug as its logo. Cute for us humans, ironic on an insect level...
Here we have an unidentified wasp species, which began arriving in droves a week or so ago. They hang out over the Fava Bean beds in the hundreds, maybe thousands, and create roving clouds in the rest of the garden. It isn't their eating habits that please us as much as their egg-laying habits. You can't say that for many things besides chickens, can you? These wasps, just a half-inch long or so, inject an egg into each aphid they encounter. The egg hatches, parasitizes the aphid, and then, when it has eaten all there is, leaves the aphid an empty shell (see left).
Here is another strange predator, which those more skilled or experienced might be able to identify. It is enough for me to know that, with a shape like that, it is not eating Fava Bean plants.
There we have it. If we had gotten wigged out by all those aphids and sprayed, dusted or otherwise applied poisons, the aphid population would surely have been affected. But so would the populations of all the predators attracted to the aphids. It is a basic law of predation that 1) there are fewer predators than prey and 2) the reproductive cycle takes longer for predators than prey. So when it comes to bouncing back from devastation, the prey will excel. Predator populations will come back much more slowly, leaving room for a great infestation before they catch up.
So here's to our ladybugs! May they always get their way in our garden.

Fava Bean Burgers

Margo pointed out to me that it has been suggested to us that Banner Fava Beans are not the tastiest, and that the bigger the bean, the tastier it is. That said, we here prefer a modest bean that grows very well to a delicious bean that doesn't. In the past year we have learned that most parts of the plant are edible (roots being the exception), and can be delicious. Last year at a fancy fund-raising dinner for Pacifica Gardens (a wonderful educational/community resource garden project that deserves its own post) one of the plates featured Fava Bean greens, the top 6" of immature plants which were then sautéed in wonderful things and served on baby potatoes... Mmmmm!

Almost immediately after being told that, yes, fava beans grow well here, but no, they don't taste good, Margo set out to create a recipe that would do them justice. Without further ado, I am going to give you the sheet she worked up on them. Photos are of flowering plants and dying, mature plants.

Summer 2007

In the garden we have just completed our harvest of mature fava beans. In the kitchen, I am playing with my new favorite recipe, fava bean burgers. At the table, we are delighting in each new batch of burgers soon to be accompanied by our own fresh tomatoes! We have enjoyed these burgers topped with steamed greens, onions, and vegetables or on our own sourdough rolls. Fava beans have a sweeter flavor than most beans; it is a unique taste to savor. (Fava beans are known to result in an allergic reaction of varying degrees in some people of Mediterranean decent, be aware.) For those interested in trying this garden treat, here is the recipe:

Soak overnight:
• 2 c. dried fava beans Drain the beans, cover with water, and cook until soft (add a bay leaf or two if desired).
Mash beans and add:
• 1 c. onion or green onion, finely chopped
• 2 garlic cloves, minced
• ½ c. mashed potatoes
• 1 T. flour
• 1 T. fresh thyme (or herb of your choice)
• ½ t. salt
• ½ t. pepper
• pinch of cayenne
When well mixed, shape into patties and cook on a lightly oiled or well-seasoned skillet until browned. Flip burgers and brown other side. This recipe was created with the intention of being as directly “from the garden” as possible. I experimented with adding an egg to hold the burgers together more and determined it did not make a difference. I encourage you to experiment with this recipe too. If you make any delightful discoveries or improvements I’d love to hear about them! - Margo :)