The BVD stands for Back Vertex Distance, this is a measurement that is included on any prescription where the sphere or cylinder powers are higher than + or - 5.00D and to a lesser extent some prescriptions where it is less than this power.
Winged Drone | Alate | Male Ant. Drones are the only male ants in a colony. They are born from un-fertilized eggs. Drones are not like typical ants. They donât do any work in their nests, and they look more like wasps than ants. They are reproductive winged ants and so are alates.
Carpenter ants are found throughout the world, and there are many different species. The Black Carpenter Ant, Camponotus pennsylvanicus, was named by science in 1773, and was the first North American ant to be named. It occurs throughout the eastern United States and southeastern Canada. Life Cycle. Winged males and female carpenter ants engage in a nuptial flight in late spring and early summer. Mating occurs in midair, after which the queen loses her wings, locates or excavates a small cavity in wood, and seals herself in the chamber, remaining alone until her first brood develops into adult workers.