Actually the total is at least 41 species, but as I have no idea what that one thing hopping around in the rain gutter was–something in the general flycatcher-peewee-pheobe spectrum, a hopeless ID to attempt before breakfast–we shall go with forty.
The flycatcher, as the name suggests, is a voracious predator, probably stopping in to investigate the insect menu. The other insect predator I have noticed recently in my garden is a bit more subtle, but just as welcome.
I have three water sources in the front yard. Two are standard birdbaths. The third is an in-ground watering hole, made by the simple expedient of digging a hole in the clay, popping in a plastic pot from Lowes, backfilling partway with the clay and sticking a large rock in it so stuff could climb out. It is as low-tech as this sort of thing gets. Insomuch as I was thinking anything, it was that some of the non-flighted members of the animal kingdom might like a chance to wet their feet, and perhaps one of the many toads that lurk in the yard might enjoy a swim now and again.
I refill it every couple of days with the hose, to replace whatever’s evaporated, and to kill off any mosquito larvae that might be lurking, since we have all been told that any standing water will lead to the entire neighborhood dying of West Nile virus within the week. But an interesting thing has occurred…there aren’t any.
I’ve got larvae in the other two birdbaths, which are summarily executed with the hose during regular watering. But this much deeper watering hole is mosquito larvae free.
What it DOES have are dragonfly larvae.
Dragonfly larvae are little swimming dark bits, and they eat mosquito larvae for lunch…and breakfast, and dinner, and afternoon tea. The birdbaths are not deep enough to tempt them, but my crude little watering hole apparently is. (No idea what species, would need a magnifying glass–probably the common whitetails that are all over the yard, at a guess.) I don’t know that it’s a large enough environment for one to actually eat enough to become a full-grown dragonfly, but certainly they’re keeping the mosquito population completely under control.
This is the sort of thing you only get by not using insecticides (and probably not being close enough to any neighbors for THEM to use insecticides) and I don’t know that I’d rely on them as mosquito control in an urban area, unless you had a ton of dragonflies in the area already as indicators of environmental quality…but damn, it’s kinda cool to see even such a terribly simple food chain in action.