Comstock mealybug coms·tock·mea·lybug uncommon noun 1. Asiatic insect introduced accidentally into United States; pest on citrus and apple trees SynonymsComstock mealybugComstock's mealybugPseudococcus comstocki Related words Broader terms mealybug Parts Pseudococcus WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.