Method for the Efficient Deployment and Recovery of Ixodes scapularis (Acari: Ixodidae) Nymphs and Engorged Larvae from Field Microcosms

Factors affecting the survival of Ixodes scapularis Say (Acari: Ixodidae) during diapause are poorly known. This is partially due to the difficulty involved in collecting ticks that are not actively questing. A possible method to overcome this issue involves the use of microcosms containing litter material and soil, but an effective method for tick recovery is required. This study tested three methods for the recovery of I. scapularis nymphs from soil microcosms during their active and inactive periods, as well as recovery of engorged larval I. scapularis. The first method was hand sorting for 120 min; the second was sorting for 30 min before placing the contents of the microcosm into a Berlese funnel for 72 h; and the third method was placing the microcosm contents into a Berlese funnel for 72 h with no prior hand sorting. Hand sorting alone and the combination of hand sorting plus the Berlese funnel were the most effective recovery methods for both active nymphs and those in diapause. Hand sorting alone was not an effective method for the recovery of engorged larvae and Berlese funnel extraction alone was not the most effective method for any of the I. scapularis physiological states tested. Overall, a combination of hand sorting and Berlese extraction was an effective recovery method for all physiological states and was 58.3% more time-effective compared against hand-sorting alone. This method will allow researchers to process microcosm samples effectively and efficiently, improving our ability to investigate the ecology of I. scapularis during their inactive periods.