Ask Mr. Smarty Plants

According the U. S. National Arboretum, Magnolia 'Ann' is a hybrid of Magnolia liliflora 'Nigra' x Magnolia stellata 'Rosea'.  M. liliflora is a native of China and M. stellata is a native of Japan, putting it out of our range of expertise, which is plants native not only to North America but to the area in which it is being grown.

In this article from the Ohio State University Extension Magnolia Pest Leads to Sticky Situation  we learned about Magnolia Scale. We have extracted a couple of paragraphs for clarity, but you should read the whole article, which gives suggestions for treatment of the scale, to take care of the flying insects problem. 

"Another indication of magnolia scale results from the large quantities of sap sucked from the plant as scales feed. The sap provides a low-protein, high-sugar diet, and in order for the scale to obtain adequate amounts of protein, the insect must ingest excessive amounts of sap. Much of this sap is excreted by the scales, which produces a clear, sticky, sugary substance known as honeydew.

This honeydew coats twigs, leaves and anything under infested branches, including cars and patio furniture. If the honeydew is not removed, a more obvious, unattractive black fungus known as sooty mold begins to grow. This is often the first symptom of infestation that people notice. Yellow jackets, wasps and ants also are good indicators of infestations as they are often attracted to the sweet honeydew on which they feed."

In addition, here is an article from the Penn State Cooperative Extension Woody Ornamentals IPM, with more information on controlling the scale, which causes the sap exudation, which attracts the flying insects you are seeing.  You might also contact the Ohio State University Extension Office for Warren County.