Flowers that "waste their sweetness"

I have always been puzzled by flowers that go to some lengths in terms of colour or scent to appear attractive but, in my experience, are visited by very few insects.  Among those in the garden at the moment are spurge-laurel (Daphne laureola) - see below - which I visit regularly but have found nothing on but a few springtails of the kind that can be beaten out of every tree or shrub.  In mainland Europe they have been shown to be pollinated by pollen beetles (Nitidulidae: Meligethes) but, while several species are not uncommon here, they are either not yet about, or prefer something else. Maybe moths or other insects visit the flowers at night as it fruits well.

Very close to the spurge-laurel we have an ever-extending bed of lesser periwinkle (Vinca minor), Blue flowers are normally rather attractive to insects but, again, these little flowers appear to entice nothing.  Our patch was started many years ago when we first moved to South View and newly weds in the past would often plant periwinkles in their first gardens as it was supposed to promote love.  It seems to have kept Cynthia and I together very successfully.  Its flower is also said to be the item referred to in recommending that wedding gifts should include 'something old, something new, something borrowed, something blue'.

My third 'tries hard' flower is that of the cherry-plum, Prunus cerasifera, also known as the myrobalan.  It is an alien March-flowering species not known anywhere in the wild, but probably from western Asia, and often grown in this country as a hedge or used as a stock for grafting with other fruit trees. Bullfinches are very fond of the buds and these often the reduce the quantity of flower but, clearly, they had not found the branch below though they were going round the garden a week or two ago.

Although I have seen no insect visitors, it is said to be pollinated by bees and, as well as bumble bees, we have at least two species of Andrena on the wing in the garden just now.