Giant Skipper

Many know of the close relationship between the yucca plant and the yucca moth. But a charismatic butterfly in the Sandhills also has a relationship with yucca plants. Strecker’s giant skipper, Megathymus streckeri, is the largest butterfly (by weight) in Nebraska. In early June when the yucca begins to bloom, the butterfly emerges from its underground pupa, and the territorial males patrol the stands of yucca, searching for females. Males patrol in wide circles, occasionally landing on the dead yucca stems, where they resemble the old seedpods. One can actually hear their wingbeats as they patrol. The egg-laden females are more secretive, hiding in the yucca foliage and only flying from plant to plant to lay a single egg. However, if frightened, the female can fly off at an incredible speed. The egg hatches in about ten days, and the larva burrows into the base of the plant, eating, tunneling, and growing until eventually reaching the root. The larva spends the winter in the root, finishes its growth in the spring, and constructs a tube made of silk and its own excrement leading to the surface. Males emerge in late May or early June, with females emerging about a week later. A good place to see these “giants” is Valentine National Wildlife Refuge, especially in the hills between Dewey and Clear Lakes.