Sentence:  <WSD>wheal-worm</WSD>, "n" 1. The itch-mite "acarus scabiei" 2. The acarine "Leptus autumnalis", or some similar harvest-bug: so named from the wheals or pimples left by its bite. See cut under "harvest-mite". 
Meaning of the word marked with <WSD> tags:  A harvest mite, "Trombicula" sp.