aphid invasion

My lupins looked spectacular this year.  

Until I took a closer look and found the stems covered with grey bumps that turned out to be aphids.  Lots of them.

here below is some info from https://www.westcoastseeds.com/blogs/garden-wisdom/lupin-aphids

Lupin flowers are rich in nectar, so they’re great for feeding domestic and wild bees. Like other members of the family Fabaceae, they fix atmospheric nitrogen in the soil that will feed other plants, including food crops.

The species most often grown in ornamental gardens is Lupinus polyphyllus, which does not produce edible seeds. This species is rich in alkaloids that make it unpalatable, even toxic, if eaten. The flowers open from the bottom of the stock towards the top, and are followed by pods of dark, very hard seeds.
Of the approximately 5,000 species of aphids in the world, fewer than 10% are pests of crops and domestic plants. Most have very specific relationships with particular types of plants.  
Lupin Aphids (Macrosiphum albifrons) suck fluids from lupin tissues and absorb the alkaloids, which makes them unpalatable (possibly toxic) to insects that normally control them.  Ladybird beetles, for instance, do not eat Lupin Aphids.

Aphids have a very complex system of reproduction. Throughout the spring and summer, they reproduce asexually, with babies emerging from eggs within the mother. In the fall, they reproduce sexually, and lay eggs for overwintering.

When conditions are right, they can produce three to four generations in a single summer, so the populations can increase with unbelievable speed. 

Because ladybugs were not eating these lupins, the author decided to encourage fungus growth on the aphids.  He sprayed them with water every evening to provide the moist environment needed for the fungus to thrive and kill the aphids.

If you look carefully at the second picture, you can see a ladybug in the top left corner. 
Maybe it was perplexed by how bad the aphids tasted!