You are admiring the roses when you notice what appear to be flecks of white cotton. Closer inspection reveals the stems crawling with green bugs: aphids. The white flecks are their moulted skins.
The roof of your car, parked under shade trees, is covered with a sticky coating. Lick your finger and the substance tastes sweet: aphids. The substance is called 'honey dew.' You've been shat upon from a great height.