Modification of key to American Hydrocanthus (Young 1985)

Young’s (1985) key to the Hydrocanthus is not easily modified given the unique character combinations present in the taxa described herein and the format of his key. However, the modifications presented below in combination with illustrations of the median lobe here and in Young (1985) and the diagnoses of the species should aid in identification of the taxa.

Hydrocanthus paludimonstrus will key to couplet 2 in Young (1985), but doesn’t fit either choice very well. The following two couplets replace couplet 2.

2a(1 ') Median lobe of aedeagus with apex truncate (Fig. 5) with long, straight apicodorsal spine; lateral pronotal margins strongly rounded (Fig. 2); total length 4.4–4.6 mm ------------------------------------------------------------------------------ --------------------------------------------------------------------- H. (s. str.) paludimonstrus Miller, n. sp.

2a ' Median lobe of aedeagus not truncate, if so then without long, straight apicodorsal spine, if truncate and with long, straight spine (i.e., H. debilis) then length less than 4.0 mm and with lateral pronotal margins not as strongly rounded --------------------------------------------------------------------------------- 2b

2b(2a ') Total length greater than 4.1 mm ---------------------------------------------------------------- 3

2b ' Total length less than 4.1 mm --------------------------------------------------------------------- 17