The best has been around for decades in use in dairy farms, horse ranches, etc. and is called Pyrethrin. Lots of local companies have sprung up spraying it every three weeks or so, with free call backs if the little buggers pop up. Mosquito Authority is the one I use and it reclaimed my yard from being in a fog of bugs to a nice day outside. All my neighbors thought the population had dwindled naturally until I told them... of course none offered to kick in any cash... ain't cheap but is worth every penny. At least one person here has bought the gear to do his own spraying and does the odd job or two for friends/neighbors, so can be done cheaper after that initial investment.
From your favorite Wiki:
The
pyrethrins are a class of
organic compounds normally derived from
Chrysanthemum cinerariifolium that have potent
insecticidal activity by targeting the nervous systems of
insects. Pyrethrin is synthetically made by industrial methods, but it also naturally occurs in chrysanthemum flowers, thus is often considered an
organic insecticide, or at least when it is not combined with
piperonyl butoxide or other synthetic
adjuvants.
[1] Their insecticidal and insect-repellent properties have been known and used for thousands of years.
Pyrethrins are gradually replacing
organophosphates and
organochlorides as the pesticides of choice, since these other compounds have been shown to have significant and persistent toxic effects to humans. Because they are
biodegradable compounds, pyrethrins are now widely regarded as being preferable to
pyrethroids, which is the name of a group of synthetic analogues of pyrethrin that accumulate in the environment. Pyrethrins are considered to be low-toxicity pesticides from a human health standpoint.
Now you know why your grandma always had those stinky flowers around the porch... ;-)
