Mosquito Menace

Susan Ellis, Bugwood.org

It was sometime around fall, 2001 that I began to notice them. I was working on a garden project in Park Slope. In the middle of the day I was being drained of my blood by a kind of mosquito that I had never seen before. They were out in the middle of the day. They were non-stop. They were the Asian Tiger Mosquito.

I grew up in these parts. I comfortably told anyone engaged in a conversation about mosquitoes that where I grew up, mosquitoes came out in force at dusk only. Sometimes, though rarely, they chased us in. In our urbanized region, mosquitoes were never as prevalent as in the north woods and dry summers made them even less frequent. This was my mosquito experience until Brooklyn 2001, when everything changed.

These new mosquitoes were day travelers, preferred shady spots, and didn't have any noticeable water to breed in. I thought maybe a sump or drain had some water in it, but it never seemed enough to promote the quantities of mosquitoes I was seeing.

Leap forward to now. My tomato patch is an incredible reservoir of the Asian Tiger Mosquito. None of our common mosquitoes anywhere to be found. Yet, when I walk into the vegetable garden I am assaulted by tens, maybe 100 little black and white striped mosquitoes. They are aggressive and the welts itch immediately. My friends with vegetable gardens are chased out of them regularly. Many have come to using Deet where before they did not.

I have noticed that I do not get one mosquito while tending to the super sunny front flower garden. Never a bite until, maybe, the sun goes low behind the trees. I have noticed that in the shady afternoon of the vegetable garden I get swarmed like crazy. I get drilled by them in the sunny morning too, but not nearly as much as the shady afternoon. It is worse now that the tomato plants are full and lush. I've seen the mosquitoes sitting on the leaves before they realize a meal has just stepped in. They hide under the canopy of leaves, I do not think they like the full sun. I do not have standing water in the garden, but I do have planter boxes that get watered. I now question whether it is possible for the Asian Tiger Mosquito to breed in wet areas without standing water. I think it may be.

My Mosquito notions:
Asian Tiger Mosquitoes like shady sites
They only need wet soil, not standing water to breed
They feed at all hours of the day
They are present where other mosquitoes are not
Highly aggressive
Roost in plant canopy
Do not tolerate full sunshine

Susan Ellis, Bugwood.org

A Google Search turns up some facts:

• In 1985 the mosquito turned up in Houston, Texas. By 1995, it made its way to Southern New Jersey. At this time it is in most of the Eastern United States. So my 2001 time frame seems to make some sense with this time line.

• The mosquito apparently lays its eggs in dry containers (tree holes, tires, pots, etc.) and those eggs are hardy enough to wait until water arrives. So maybe for me it is not the damp soil, but dry planter sides that then get inundated every few days or so with water from the watering can that promote the breeding. Another hot spot maybe the water runoff grate at my street corner, just four feet from my garden.

• The mosquito apparently was a forest dweller in its home range. This may explain the attraction to the shady afternoon garden. Strong sun may be a bit too much for it (?).

• It feeds heavily in the late afternoon. Well, that crosses over with the shady part, so...

• Municipal mosquito spraying doesn't work because they do this at night and the Asian Tiger is active in day. The Tiger is also very localized, never traveling more than 200 yards or so. This means that every person who has the bugger would have to spray. But then you would kill everything else active in the day, like bees and dragonflies. Plus, who likes spraying?

• The only solution is to eliminate containers that might hold the slightest amount of water. For me, this may mean my vegetable planter boxes! Oh, no! Watch me move to raised beds in two seconds!