Subterranean Behavior and Other Notes for Ironoquia plattensis (Trichoptera: Limnephilidae) in Nebraska

Ironoquia plattensis Alexander & Whiles (Trichoptera: Limnephilidae) was discovered along the Platte River in central Nebraska in the late 1990s, and basic information about its life history is not well understood. Here, we describe previously undocumented life-history traits that demonstrate strategies used by I. plattensis for surviving in fluctuating wetland environments in a landscape formally shaped by flooding. In an off-channel aquatic habitat along the Platte River, we observed 1) larvae residing in a slough that did not dry completely, 2) larvae emigrating from aquatic to terrestrial habitats 1 mo earlier than reported previously, 3) larvae moving above ground during the summer aestivation period, 4) larvae residing underground in soil during summer aestivation, and 5) mass emergence and swarming of adults after daybreak in autumn. Underground larval aestivation represents a previously undocumented behavior for this species. It is unclear whether aestivating underground represents an unreported common behavior or an infrequent response to local disturbances. At our site, insects may have been responding to a prescribed burn in April and introduction of cattle in mid-May that yielded the site unsuitable for aboveground aestivation. Additional studies on the life history for I. plattensis are warranted to help manage, locate, and protect the few sites where it occurs.