They float like orange and black knuckleballs. Wafting on the winds . . . sometimes dipping, somtimes moving upward as they fly up to 2,500 miles to their winter hibernation grounds in the mountains of Mexico or cypress and eucalyptus trees in southern California.

These are the monarch butterflies, whose fourth generation of this summer are now being born and soon will be adults that fly through our back yards, pasture lands and open spaces to a safe haven for the winter months.

These adult monarchs are a colorful orange and black with many white dots on their wings. The orange portions can appear to be like stained glass panels contained by black veins. The white dots appear on the black borders.

The last of the summer’s monarchs are actually the fourth generation.

Eggs laid by adults returning north from their winter grounds begin hatching in March and April and the brilliant new generation lives only 6 to 8 weeks. The March/April group lays eggs that form the second generation of the year and hatch in May and June.

That group has the same life span and also leaves its heritage behind when the third generation comes along in July and August.

The final generation will be with us in September/ October before lifting off for a flight to the winter safety in Oyamel fir trees in the mountains of central Mexico.

A monarch lives its early life on milkweed plants . . . the same short, broad leaf weeds you see in farmers’ pastures, untamed fields and even close to rural roads.

After hatching from small white eggs, the tiny worm-like creature eats its own egg shell and then begins munching on the leaves of the milkweed plant. It outgrowns its skin several times, each time shedding and eating its “home” for added nourishment.

After a fifth skin shed, the caterpillar stage enters a clear chrysalis where it will transform itself into an adult orange and black butterfly.

The first three generations of any summer all die after a 6 to 8 week period.

But not the fourth generation. It’s that generation that perpetuates the species.

Bobbing along on the September breezes, those adult monarchs gather as much nectar from asters and other brightly colored flowers as they can and lift off for an arduous trip that can lead from central Canada and the eastern United States to Mexico.

Months later they arrive in the forests of Mexico or the small areas of California where cypress and eucalyptus trees await their yearly arrival. They gather on branches, numbering in the millions. After six or eight months in hibernation, they awaken and fly back north where the females deposit their eggs on another year’s milkweed hosts.

The returning monarchs have made two migrations by then. They are shriveled, weary and have wings that are in disrepair . . . and they finally die themselves.

The process of generational hatching begins anew.

And the orange and black knuckleballs that are the monarchs of adulthood begin munching on milkweeds again before giving us the pleasure of their colorful presence for another spring/summer.