These perfect strands of flowers are called catkins. These are the structures that produce the pollen on the pecan tree, and they are the first new growth to appear in the spring. Pecan trees are covered with catkins, and this allows the wind to carry pollen from tree to tree, fertilizing the female flowers. Pecan trees do not depend on bees or other insects to cross pollinate the flowers.
Of course, the recent collapse of so many bee colonies should be a concern to everyone. Our fellow tree nut growers who produce almonds are dependent on bees to carry pollen from tree to tree to produce viable nuts. The flower of the almond tree is self-incompatible, and so it requires a cross pollination that can only be accomplished by bees and other small flying insects.