About Paropsis
A most effective description of Paropsis will be by comparison to their (usually) smaller but more numerous sibling genus, Paropsisterna.
https://sites.google.com/site/paropsisternapages/ which often look very similar and can be found in identical habitats.
Paropsis in Latin translates to 'dish' and refers to the very convex body, looking a bit like a ladybird beetle. It is believed that the shape facilitates these insects tucking their toes and antennae under their shell to protect them from predators or annoying neighbors such as ants, who would prefer to push them away from their happy feeding grounds on succulent foliage. Ants typically farm aphids and leafhoppers and mistake leaf beetles for predators.
Leaf beetles in the mostly endemic genus Paropsis include about 71 species. This Genus is undergoing review by Gunter Maywald and some corrections will be made.
Most of these feed on Eucalyptus. Exceptions include Paropsis pictipennis, P. minor and P. confusa which feeds on tea tree or Kunzea. Not surprisingly, these species are anomalous, not fitting easily into this genus.
Paropsis usually have crenulate (wavy) or emarginate (with a point) lateral edges of the pronotum (hardened covering over part of the thoracic segment. The puncturations on the elytra are very numerous and spread fairly evenly over the entire elytra. Striae (lines of color or puncturations or grooves ) are absent or very closely stacked together laterally along the elytra. Where the puncturations are aligned, there are 20 lines but generally they appear randomly placed or in an intermediate orientation. Paropsisterna will generally have ten striae consisting of puncturations, sometimes along grooves.
Ventrally, the prosternal process has two lateral bumps in the Paropsis genus which is entirely lacking (smooth) in Paropsisterna.
Parropsis atomaria ovipositing. Churchill NP. Vic.
Image by G. Walker demonstrating emarginate pronotum.
Paropsis ornata Gin Gin. Qld Image by Geoff Walker
demonstrating acervate elytra.
From Reid;
6(5) Prosternal process with 90° angled lobe on either side of base (Fig. 86), or, if lobe reduced to small rounded swelling (one rare Tasmanian species), then with deeply emarginate lateral pronotal margins and acervate elytra (pronotal angles without setae; labrum not densely pubsecent; sides of pronotum often emarginate or coarsely crenulate; elytra usually non-striate and acervate (interpunctural spaces convex); most species with colour loss after death) ............................. Paropsis Olivier