Interesting characteristic of malathion
Came across this detail in one of MSU's newsletters.
"Malathion sprayed on strawberry flowers decreased to 2.70 percent of the initial concentration within two days of application." [in hot weather]
I knew Malathion was short lived, but not that short. A 3% residue after only 2 days? No wonder multipurpose sprays that use Malathion are so ineffective.
(Don't know why the tests were done on flowers since you'd want to avoid spraying blooms.)
Here is a link that might be useful: MSU - Counteracting adverse weather effects on deposition and degradation of insecticides