Outdoors in the Land O'Lakes - July 17, 2008

The White Admiral & Other Bugs

Outdoors in the Land O'Lakes by Lorraine Julien

If you’ve noticed a beautiful black and white butterfly gliding around your garden in recent weeks, it is probably the White Admiral (Limenitis arthemis). Its arrival marks the official start of the summer season.

The adults emerge in late June and early July and then mate shortly thereafter, with the females laying eggs on host trees. These trees include birch, aspen, poplar and willow. The adults are diurnal which means they fly from morning until just after dusk.

The adult is black with wide, white wing bands and a row of dark reddish spots along the outside of the white band. It prefers forests, clearings, gardens and parks ranging all over eastern North America. Host plants include birch, aspen, poplar and willow.

Some of its favourite foods are fermenting fruit such as ripe bananas, overripe apples, etc. Perhaps that is why I see them here as we do throw a lot of fruit peels into our compost. Strangely enough, in my mind, this butterfly is also attracted to mud puddles and fresh scat. With all the rain we’ve had, and, consequently, mud puddles, it’s no wonder there seem to be so many around this year. White Admirals also love the bleeding sap on birch trees that have been tapped by yellow-bellied sapsuckers.

It’s interesting to note that the White Admiral is the insect emblem of the Province of Quebec.

Bug Update – the Good, Bad and the Ugly

In my last column, I mentioned noticing some shiny black bugs (about an inch long) with long black antennae and I was concerned they might be the feared Asian Long-horned Beetle which had invaded an area of Toronto a couple of years ago.

I’ve since learned that there is a fairly harmless native bug that looks very similar to the Asian Long-horned and, on closer scrutiny, I’m now sure that the beetle I saw is the White-spotted Sawyer – an apparently beneficial forest insect that feeds on dead and dying conifers. Sawyers are attracted to firewood and really love to chew on fallen trees, speeding up the rotting process. Apparently you may be able to hear a chewing sound coming from a rotten tree trunk where they are feeding! If you are a woodlot owner and suspect that Sawyers have invaded your fallen trees, process the logs as soon as possible. If these beetles are present, their larvae can tunnel through the logs reducing their value.

Of more concern for the Ottawa area and other parts of eastern Ontario is the Emerald Ash Borer. It has been reported in a suburb of Montreal and it may only be a matter of time before it arrives here. Originating in eastern Asia, this pest was first discovered in Canada and the U.S. in 2002. The Emerald Ash Borer kills all species of ash (Mountain Ash is not a true ash so it would not be affected). It has already killed millions of ash trees in southwestern Ontario, Michigan and surrounding states. It is a metallic green beetle about 8.5 to 14 mm in length.

The EAB has spread quickly mostly due to the movement of firewood, nursery stock, trees, logs, lumber, wood with bark attached and wood or bark chips, and the fact that it can fly up to several kilometers.

This information was taken from a Pest Alert issued by the Canadian Food Inspection Agency; however, if you’d like information on these and other forest pests, check out the CFIA website at www.inspection.gc.ca

The CFIA has asked that you contact them if you see signs of this beetle on your ash trees or if you plan to move firewood. The contact telephone number re the EAB is 1-866-463-6017, weekdays 8 a.m. to 4 p.m.

Please feel free to report any observations to to Steve Blight at natureobservations@rogers.com or Lorraine Julien at outdoor1@look.ca