Pucerons, frozen lady bugs and bird poop…May 14, 2010
“It looks like a bird pooped on our mandarin tree,” I said to Raphael.
He looked at me strangely, “Why not? It’s outside where birds poop.” He went back to digging the drainage ditch along the stone wall.
“But it’s not a big drop like you normally see. They’re tiny drops inside, along the branches. And there are little bugs crawling around it.”
My strange comment brought him over to investigate. There is an advantage to being married to an agricultural engineer. His knowledge comes in handy when I am clueless. “That’s not bird poop,” he said brushing it away. “It’s not poop at all. It’s ladybugs that got caught in the frost.” These grey and black smudges on my mandarin tree were the dusty remains of lady bugs that got burnt up in the freezing winter. The bugs, he told me, are pucerons. Pucerons, aphids in English, also known as plant lice, attack the grape vines as well other plants. “You need to treat this with insecticide,” he said. I didn’t want to use insecticide on a tree I’m hoping will one day produce edible fruit and I found that a strange comment coming from someone who doesn’t use it on his vines and is an organic grape grower. But then, I don’t want these pests killing my tree either.
Recently I was in the Drougerie, not a drug store, but a store which sells cleaning supplies, paint, and other household odds and ends. I was looking for a product to clean and seal old tile called tomette. The shop owner gave me a bottle of savon noir liquid a l’huile de lin, or liquid black soap made from linseed oil, along with a list of things it was good for including treating plants for bugs. This caught my attention as my yet untreated mandarin tree was still on my mind. I asked if this could work on the pucerons. Most definitely, she said writing down the formula of 20ml oil to 1 litre of water.
Returning home, I found an empty spray bottle and mixed the formula. This was a few weeks ago during the unseasonable heat of April, and seeing the shiny coating after spraying at mid day, I wondered if I was causing more harm to the tree. Could treating the tree in full sun be like watering it in full sun? I sprayed the entire tree concentrating of the leaves that were most under attack. Two days later, I went for a second look. Honestly, I couldn’t see a difference. Nothing seemed to have changed, potentially a good thing since no new bugs seemed to be living on my tree. But the old pucerons were still living among the lady bug dust. It’s too bad the lady bugs didn’t survive the winter, it turns out they are a natural preditor to the aphid.
I sprayed again thinking it needed to be treated more often. The next time I went back, there seemed to be fewer bugs, or maybe that was just my hopeful imagination. Spray, spray, spray.
I haven’t had a look since we began this rainy period of May, a perfect time for the bugs to reproduce and attack my tree. Since Raphael is busy dealing with the possible effects this rain could have on his vines, I’m wondering if my tree is suffering.
Recently I discovered some new tricks – matches planted with the tip in the soil or tobacco, soaked in water for 24 hours, then filtered and mixed with vinegar and liquid soap. My trees were not planted with matches in the soil but I may go shove a few in. I’m not ready to try the tobacco mix as I’ve been told by more than one person to stick with the savon noir, it works. I’ll let you know.