Ladybugs for asparagus beetle
Minnesota and Maryland Extension both name lady beetles (Minnesota specifies the larvae) among the predators that eat asparagus beetle eggs and small larvae. They work alongside the egg wasp Tetrastichus asparagi, which can kill up to 70% of eggs. Minnesota's advice is to leave these beneficials alone, and it warns that pesticides kill beneficial predators and parasites. In small gardens it recommends hand-picking adults and larvae into soapy water instead.
Before you act
Everyone's first idea for aphids, and the one beneficial where buying is usually the wrong move. The ladybugs sold by the tub are convergent lady beetles collected from the wild, and UC IPM says most fly away within a day or two of release, even when aphids are plentiful. The larvae do much of the eating, and they turn up on their own wherever there are aphids. How to recognise it, what it is confused with and how to keep it around are on the full Ladybugs profile.
Other controls for asparagus beetle
No other reviewed control is listed for this pest yet.