In the course of faunistic studies of Indiana Collembola, seasonal occurrences of the two species Hypogastrura packardi (Folsom), 1902 and H. notha (MacNamara), 1922 were found to exhibit seasonal dimorphism and population dynamics similar to those patterns observed in cyclomorphic species previously reported in literature (Leinaas 1981 a,b).
Waltz, R. D. and Hart, J. W.
"New Synonomy in Hypogastrura (Collembola: Hypogastruridae),"
The Great Lakes Entomologist: Vol. 18
, Article 7.
Available at: http://scholar.valpo.edu/tgle/vol18/iss4/7