Definition of cockchafer in English:
 cockchafer
nounˈkɒkˌtʃeɪfəˈkɑkˌtʃeɪfər
A large brown European beetle which flies at dusk and is a destructive plant pest, both as an adult and a larva.
Melolontha melolontha, family Scarabaeidae
Also called May bug
 Example sentencesExamples
-  At peak abundance, cockchafers reached densities of more than 50 individuals per meter of twig on some fruit trees and on shrubs.
 -  What a pleasant change from the labourer's unvarying meal of bread, lard, and bacon would be a good dish of fried cockchafers or grasshoppers!
 
Origin
  
Early 18th century: from cock1 (expressing size or vigour) + chafer.
   Definition of cockchafer in US English:
 cockchafer
nounˈkɑkˌtʃeɪfərˈkäkˌCHāfər
A large brown European beetle that flies at dusk and often crashes into lighted windows. The adults are damaging to foliage and flowers, and the larvae are a pest of cereal and grass roots.
Melolontha melolontha, family Scarabaeidae
 Example sentencesExamples
-  At peak abundance, cockchafers reached densities of more than 50 individuals per meter of twig on some fruit trees and on shrubs.
 -  What a pleasant change from the labourer's unvarying meal of bread, lard, and bacon would be a good dish of fried cockchafers or grasshoppers!
 
Origin
  
Early 18th century: from cock (expressing size or vigour) + chafer.