Hornet wasp feeding. Adult worker hornet wasps Vespa crabro eating the flesh of fruit. This wasp will only enjoy fruit towards the end of its life, late in the season, when the social job of rearing other wasps in the nest has ended. Vespa crabro typically feeds on insects and carrion. This meat is also fed to developing wasp larvae as a high protein diet. When autumn approaches and new queens mate and prepare to hibernate over winter, the workers gradually succumb to the colder weather. It is at this time that they turn their attention to fruit and other sweet materials.