We have developed monoclonal antibodies (MoAbs) to the storage mite Lepidoglyphus destructor (Ld). Employing these anti-Ld MoAbs (Ld-MoAbs) in ELISA and ELISA inhibition techniques we have analysed the reaction pattern of Ld-MoAbs to both non-pyroglyphid and pyroglyphid mites. The storage mite Glycyphagus domesticus (Gd) exhibited most efficient inhibition, followed by Acarus siro (As), Tyrophagus putrescentiae (Tp), Dermatophagoides pteronyssinus (Dpt) and Euroglyphus maynei (Em). Of the two pyroglyphid species, Dpt showed at least 1000 times less inhibition than Gd. Two of the MoAbs immunoprecipitated a band of 39 kD whereas the third reacted weakly, with a high-molecular band of approximately 110 kD. The Ld extract was also subjected to various reagents and conditions and the antigen was heat stable, it was not affected by low pH, or sensitive to dimethyl sulphoxide (DMSO) or paraformaldehyde. After exposure of the extract to various reagents, such as protease trypsin and periodate, we conclude that the epitopes recognized by Ld-MoAbs were of carbohydrate rather than of protein nature. It would thus seem that MoAbs recognize the carbohydrate part of a glycoprotein.