【英语时差8,16】会发射紫外线的蜘蛛(下)(在线收听) |
Craig and Bernard did laboratory experiments showing that fruit flies are two to three times more likely to fly toward a simple web reflecting ultraviolet light than toward a web not reflecting it. Craig and Bernard also found that many spiders, especially those who forage near flowering plants, make non-ultraviolet-reflecting webs, then sometimes decorate the webs with special ultraviolet-reflecting silk laid down in flower-like patterns. The bodies of these spiders also reflect ultraviolet light. The two scientists observed webs built by a type of large garden spider in Panama and found that decorated webs with spiders present caught fifty-eight percent more insects per hour than undecorated empty webs. |
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