These tiny green apterous water treaders were abundant on Lake Creek in southern Williamson Co., TX. Although not measured in the field, knowing the capabilities of my point-and-shoot camera allows me to estimate that most/all of them were 3 to 4 mm long. Of three N. Am. species of Mesovelia (M. cryptophila, amoena, and mulsanti), only the latter two have been recorded in Texas and amoena only in s.e. coastal Texas (Jackson Co.)(discoverlife.org). Moreover, a paper by Kort-Gommers and Nieser* suggests that the latter two species can be separated by size, amoena being only 2.1-2.3 mm long and mulsanti ranging from 3.0 to 3.8 mm. I'm including images of five (presumed) different individuals from the sharpest images I obtained. The last image is a blurry picture of a presumed winged adult form; these are extremely fast movers across the water and algal surfaces. See also, http://bugguide.net/node/view/165058
(This was a life family for me.)

• Kort-Gommers and Nieser. 1969. Records of Antillean Water-Striders (Heteroptera). Pp. 75-77, In: Studies on the fauna of Curacao and other Caribbean Islands, No. 112.