A century ago, millions of Quino checkerspot butterflies flew above Southern California. Each about the size of a paperclip, the Quinos hatched in great numbers each spring.
Toward the end of the twentieth century, however, the development of farms and cities dramatically reduced the butterfly’s habitat. By 1997, the population of the Quinos had declined to a tiny amount of its historical numbers.
The Quino’s situation continued to worsen. Wildfires burned much of its habitat, and temperatures were getting warmer and drier, making the environment more difficult to the butterfly’s host plant called the dwarf plantain.
Scientists knew that Quino caterpillars relied on the dwarf plantain as a food source. Each spring, the adult female butterflies laid eggs on dwarf plantains. When the caterpillars hatched, they fed on the plantain leaves. However, in the hot, dry summer, the plantains died off. The caterpillars responded by entering a state called diapause. Then, when normal winter rains came and the plantains’ flowers came out again, the caterpillars came back to life and started eating. Once they’d grown large enough, the caterpillars formed pupae and emerged as adult butterflies. This strategy worked well in most years, but as average temperatures rose and rainfall decreased, the caterpillars weren’t getting sufficient food, and fewer developed into butterflies.
Because the area where they lived was surrounded by developed cities and desert landscapes, the Quinos had limited options. They took off anyway, flying eastward into the hills. They landed in mountainous open spaces east of Los Angeles and San Diego. They found no dwarf plantains there. The females began laying their eggs on the leaves of other plants, primarily the Collinsia concolor. These plants remained green longer into the summer months. When the caterpillars Quinos survived, and their numbers grew in their new home.
Scientists were surprised when they began encounter innumerous Qunios in the eastern hills. They were cheered to learn that these small insects had adapted to changing conditions. The Quinos demonstrated the toughness needed to survive by finding not only a new habitat, but a new food source, too.
Meanwhile, scientists had been raising Quino caterpillars in a lab and released hundreds of caterpillars into protected areas around San Diego. Between the efforts of scientists and the butterflies’ own actions, more of those colorfully checkered wings may soon be seen fluttering above the Southern California skies.
【小题1】From the passage, we know Quino checkerspot butterflies in Southern California ________.| A．were an endangered species | B．couldn’t survive the winter cold |
| C．were very adaptable to environmental changes | D．couldn’t respond to the food shortage on their own |
| A．They travelled to a new habitat. | B．They found new dwarf plantains. |
| C．They laid more eggs on host plants. | D．They learned to fly high up in the mountains |
| A．Dying from hunger. | B．Stopping bodily functions. |
| C．Becoming more active. | D．Surviving the hot summer. |
| A．Quino Checkerspot Butterflies: Get Help |
| B．Quino Checkerspot Butterflies: Endangered |
| C．Quino Checkerspot Butterflies: Small, but Strong |
| D．Quino Checkerspot Butterflies: Find a New Habitat |
