Remember leafminers: some growers are reporting seeing them for the first time in many years

摘要

You need to monitor the crop closely to detect adult leafminer and/or damage on the leaves. Yellow sticky cards are excellent monitoring tools far adult leafminer. Back in the mid-1980s, a small yellow and black fly came close to wiping out the chrysanthemum industry in North America. The serpentine leaf miner Liriomyza trifolii caused huge amounts of damage wherever chrysanthemums were grown. Losses in the chrysanthemum industry in California were estimated at 93 million dollar between 1982-1986 (Newman and Parrella, in Greenhouse Manager in 1986). To the best of my knowledge, no one ever put a dollar figure on the losses to the industry in Canada, but I can still remember when I started with OMAF (Ontario Ministry of Agriculture and Food) in 1988growers were spraying up to three limes per week and still throwing out whole beds of mums.