Definition: Mouthparts modified into long or short, sclerotized piercing devices that are used to penetrate the host/prey/substrate to gain access to food, and liquids are transported through the food canal with the aid of a pressure gradient created by a sucking pump.
Definition: A depression caused by erosion by water or ice. Low-lying land bordered by higher ground; especially elongate, relatively large gently sloping depressions of the Earth's surface, commonly situated between two mountains or between ranges of hills or mountains, and often containing a stream with an outlet.