1. RE: fugus nats are driving me nuts

Documents: Garden Design:

Fungas Gnats & IUCN’s Red List

Fungus gnats--not easy to get rid of; young pine trees in containers; and the IUCN’s Red List!
by Art Drysdale
by Art Drysdale


Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at

November 30, 2003

It is thought that the last specimen in the World of the St. Helena olive (Nesiota elliptica) died this past week on that South Atlantic island. Photo courtesy of Rebecca Cairns-Wicks and IUCN.

Two interesting questions arrived in my e-mail inbox this week. The first was from Barrie and Marie, of unknown location. Barrie asked: “I raise peppers in an indoor greenhouse with white plastic walls and ceiling. Try as I might, I cannot get rid of fungus gnats. As a last ditch attempt I bought a total release fumigator but the directions have made me leery of using it. What do you say?”

In subsequent e-mails, I asked Barrie to tell me just what product he had purchased. He then advised: that it was the Doktor Doom Total Release Fumigator. I told him that I would not have any concern about use of the product, especially in a contained space such as his greenhouse. Naturally, the product’s precautions should be observed, the two primary ones being to turn off any pilot lights and/or open flames; and not to re-enter the fumigated area for two hours.

Barrie and any others with this pest should also remember that because they complete a major part of their life cycle in the soil, there will, for a time, be insects re-appearing. That means having to do the fumigation treatment over again, likely within a week or two.

I also suggested that there are other controls for fungus gnats; the Nu-Gro company’s Wilson division has an Insect Spray containing .25% each of Resmethrin and Tetramethrin that is designed for insects like fungus gnats, springtails and scale. However, I still think the Doktor Doom Fumigator is an excellent way to go.

Madge Veitch wrote: “I bought two of these (small pine trees) for each side of my front door and have sunk them pot and all into the containers--I watered them and piled the soil around them--will they survive the winter here in Innisfil, Ontario or is there anything else I should do. I know you do not like wrapping--they are about two feet high and I would like to plant them in the spring.”

Although Madge didn’t say which pines they are, I’ll assume they are young trees of one of our hardy species such as Scots, white, Mugho or Austrian. They would have been better planted directly into the containers rather than left in their pots, but it is likely too late now to re-plant them. There should be nothing else she need do except to make sure the soil in the pots (and containers) remains moist until final freeze-up.

This week, the International Union for the Conservation of Nature (IUCN) species survival commission released its annual Red List of threatened species. As reported in Nature magazine plants and animals native to smaller islands are the “unfortunate stars of the new Red List.

“On Hawaii, 85 plant species that are found nowhere else are in danger of extinction. The same goes for 35 types of snail on the Galapagos Islands.

"‘It's a tragedy,’ says Craig Hilton-Taylor, an IUCN programme officer based in Cambridge, UK. ‘We've wrecked some incredibly diverse places.’

“One name may already have to be removed from the inventory. The St Helena olive (Nesiota elliptica) seems to have gone extinct within the past week. The leaves of the last known tree, on the South Atlantic island of St Helena, have withered and died.

“Invasive species are the biggest threat to island wildlife, the list confirms. Goats, pigs, cats and rats eat the natives and destroy their habitat.

“Marauders can be warded off--the introduced domestic cats that once threatened the seabird colonies of Marion Island, off the coast of South Africa, for example, have been eradicated. But, it took 19 years and involved shooting, trapping, and introducing disease.

“Worldwide, more than 12,000 species now fall into the three categories closest to extinction: vulnerable, endangered and critically endangered. The list is growing as situations worsen, but also as information improves. Plants, in particular, are becoming better studied: this year's list includes seaweeds and lichens for the first time, and contains the first complete assessment of cycads and conifers.

“The IUCN updates its Red List each year, based on information from 8,000 experts around the world.

“Next year's list will include the first complete assessment of amphibians, as well as reassessments of all mammals and birds. Early signs are worrying, says Craig Hilton-Taylor: ‘The indication from birds is that things are getting worse.’”

I have more on this Red List that I’ll write about a future week.



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