The effects of water exposure, soil conditions, and fungus exposure on hatching of the larval lone star tick,Amblyomma americanum(Acari: Ixodidae)

We examined whether water functions as a developmental cue for hatching in the lone star tick, Amblyomma americanum. The experiments examined various exposure routes to water: submersion, relative humidity and an ecologically relevant setup of moist soil along with soil fungi to mimic fungus–egg interactions at oviposition sites. We demonstrate that eggs survive for up to a week underwater; increasing water entry into the egg suppresses hatching; and exposure to liquid water, H2O or D2O, neither shortens nor prolongs the incubation period of those eggs that remain viable. In response to relative humidity, hatching takes place most readily when the air is nearly or fully saturated (with water); relative humidity neither shortens nor extends incubation period; and the length of incubation time is unrelated to the percentage of larvae that hatch. When incubated with fungi (common soil isolates), Aspergillus niger, Metarhizium anisopliae, Penicillium glabrum, Rhizopus stolonifer, Scopulariopsis brevicaulis, e...