Ochteridae (Velvety Shore Bugs)

Ochterids are found at the edges of rivers and large pools of water like lakes and dams. They predate invertebrate larvae. Adults avoid the water but nymphs are capable of restrictive sub-surface exploration. Nymphs are very cryptic with the habit of scooping and packing wet sand on their backs.

Both Australian genera, Megochterus and Ochterus, are found in Tasmania. Megochterus are larger, being over 8mm in length, have thicker antennae (last segment semi-oval), the hemelytral membrane contains twenty or more cells, and the 'nose' (frontal plate) distinctly protrudes in front of the eyes (viewed above and laterally). Ochterus are never above 6.5mm in length, the last two antennal segments are very narrow, the hemelytral membrane with around seven cells, and the frontal plate not unusually produced forward. Tasmania has one species of Megochterus, M. nasutus, and two Ochterus, O. australicus and O. eurythorax. It is not possible to confidently separate the two Ochterus species on external features.

Genus Ochterus

Ochteridae Ochterus
 
Genus Megochterus

        https://sites.google.com/site/insectsoftasheteroptera/suborder-heteroptera/ochteridae-velvety-shore-bugs/genus-megochterus

References

Baehr, M. 1989. Review of Australian Ochteridae (Insecta, Heteroptera). Spixiana (München) 11: 111-26.

Kormilev, N. A. 1971. Ochteridae from the Oriental and Australian regions (Hemiptera-Heteroptera). Pacific Insects 13 (3-4): 429-44.

Landsbury, I. and Lake, P. S. 2002. Tasmanian aquatic & semi-aquatic hemipterans. Identification and Ecology Guide No. 40, Cooperative Research Centre for Freshwater Ecology.