Dimethoate is a systemic insecticide and has been available for
purchase over the counter for several years and I believe it is still
available at garden centers.
http://www.wrpmc.ucdavis.edu/NewsAlerts/dimethoate.pdf
Alternative chemistries have been shown to be effective tools, but
the systemic nature of Dimethoate controls against aphid for a longer
time, reducing the number of applications. The newer chemistry is
double to triple the cost of Dimethoate. The producer must use
multiple applications or must add Dimethoate to the mix to achieve
effective control. This is neither economically or environmentally acceptable.
Jim Young
****************************************************
* General Information About BEE-L is available at: *
* http://www.honeybeeworld.com/bee-l/default.htm *
****************************************************