Definition of frass in English:



  • 1Fine powdery refuse or fragile perforated wood produced by the activity of boring insects.

    • ‘We felt the fine, sharply scented frass of a carpenter ant colony with our fingertips.’
    • ‘By the end of the experiment, an average of 25% of the cotyledon of Q. alba acorns had been reduced to frass, while there was no apparent damage in any of the final sample of RO acorns.’
    1. 1.1 The excrement of insect larvae.
      • ‘This frass is considerably different from the pelletized frass left by drywood and dampwood termites.’
      • ‘As larvae feed, they spin silken threads, trapping the dying florets and their frass, giving the sunflower head a trashy appearance.’
      • ‘Larvae that had consumed leaf material frequently had green coloured alimentary canals, green frass and a portion of the leaf surface was scarred.’
      • ‘The chemical analyses of the body and frass of Blepharida flavocostata revealed almost no match to the constituents found in B. biflora.’
      • ‘On closer inspection, obvious discolored wounds can often be seen at the base of the plant and stems, and at the wounds, masses of a yellow-green grainy substance known as frass - the hygienic German word for caterpillar excrement.’
      • ‘They seemed to hunt by scent, ignoring nests with faux frass in the form of small black glass beads.’
      • ‘Keep the grass mowed or mulched around the trunks of your fruit trees and watch for the telltale rusty frass of borers - these larval worms can be dug out with a sturdy wire.’
      • ‘I measured digestibility as the proportion of eaten plant biomass not deposited as frass by 0800 the following morning.’
      • ‘As a bit of frass starts to emerge from the caterpillar, it pushes a hinged plate against a ring of blood vessels surrounding the anus.’
      • ‘Thus removal of cues for natural enemies is likely to have been an important selective force in the evolution of frass ejection behavior in shelter-dwelling larvae.’
      • ‘The notion that Tunisian blue-striped caterpillar frass could help you burn fat overnight while you sleep, strengthen muscles without exercise, erase wrinkles and improve your memory is too tempting for some folks to resist.’
      • ‘One downside of group dining is that chemical signals from the larvae and their frass can attract parasitoids.’
      • ‘After collecting, we removed litter from litter bags and gently cleaned it of roots, invertebrates, frass, and soil.’
      • ‘Often dark black pellets of frass will be in the nest with the caterpillar.’
      • ‘Identifying the presence of frass coupled with damage is a strong indication of the presence of a caterpillar, or in some cases, beetle larvae.’


Mid 19th century: from German Frass, from fressen ‘devour’.