The Collaborative International Dictionary
Chinch \Chinch\, n. [Cf. Sp. chinche, fr. L. cimex.]
(Zo["o]l.) The bedbug ( Cimex lectularius).
(Zo["o]l.) A bug ( Blissus leucopterus), which, in the United States, is very destructive to grass, wheat, and other grains; -- also called chiniz, chinch bug, chink bug. It resembles the bedbug in its disgusting odor.
Wikipedia
Blissus leucopterus also known as the true chinch bug is a small North American insect in the order Hemiptera and family Blissidae. It is the most commonly encountered member of the genus Blissus, which are all known as chinch bugs. A closely related species is Blissus insularis, the southern chinch bug.
The name of the chinch bug is derived from the Spanish word . This word has come to mean “pest” and is used in many phrases such as , meaning tiresome or troublesome. The word “chinch” is also used for the bed bug, and is derived from the Latin word cimex of the same meaning.
These bugs tend to gather on sunny open patches of turfgrass. Due to their small size, chinch bugs are hardly noticeable. Therefore, they become problems since they are considered pests that feed on stems of turfgrass.