A Method of rearing Individual Trombiculid Mites in the Field

THE taxonomy of the Acarina Trombiculidae requires stabilizing by the study of the non-parasitic post-larval stages. Fewer than sixty nymphs and adults are known out of more than five hundred species, and of these only very few can be identified with absolute certainty. Techniques for rearing nymphs from engorged larvæ are widely known and practised, but a single host often carries several or many species of chiggers, and taxonomic studies make it necessary to identify each nymph by reference to the cast larval pelt. Although this is practicable in the laboratory, it is extremely difficult to do in the field especially when moving from place to place, because nymphs may take several weeks to emerge.