ABSTRACT
The Mesoveliidae are a family of small to medium-sized, usually green or brownish bugs. Worldwide, there are only 9 genera containing 32 species, of which 22, including the 3 North American species, are in the cosmopolitan genus Mesovelia Mulsant and Rey. Considering the relative morphological homogeneity of the family, the habitat preferences of mesoveliids are surprisingly diverse. A few species are hygropetric, living on watersoaked moss or seeping rock faces, while other cavernicolous species are found on the moist slime fungus covering the walls of lava tubes or moist walls of coastal caves. Mesoveliids are predators and scavengers feeding on a variety of microarthropods and microcrustaceans at the water surface or on floating vegetation. Macropterous specimens, although considerably rarer than apterous individuals, have been recorded for all North American species with the exception of M. cryptophila Hungerford. The absence of wings is accompanied by reduction or loss of the ocelli, and simplification of the thoracic dorsum.
