Some commonly-used morphological characters for distinguishing Conostigmus and Dendrocerus males are the ocellar ratios and the shape of the ocellar triangle ( Dessart, 1995b; Dessart and Cancemi, 1987). Dendrocerus males are usually distinguished as having an obtuse ocellar triangle (POL greater than LOL) where the two posterior ocelli are closer to the compound eyes than to each other (POL greater than OOL), whereas Conostigmus males are usually thought to have an acute or equilateral ocellar triangle (POL equal to or less than LOL) where the posterior ocelli are closer to each other than to the compound eyes (POL less than OOL).
Male antennal characters are also commonly used for distinguishing between Dendrocerus and Conostigmus ( Dessart, 1995b; Dessart and Cancemi, 1987). Female antennae are indistinguishable between the two genera, but male antennae of Conostigmus are symmetrical and cylindrical in shape, whereas the male flagellomeres of Dendrocerus are usually asymmetrical and can be serrate or trapezoidal. Some Dendrocerus also have branched flagellomeres ( D. mexicali group), a state which is never found in Conostigmus ( Dessart, 1995a, 1995b, 1999, 2001).
Of course, there are some exceptions in Dendrocerus. Both the D. penmaricus species group and the D. punctipes species group have symmetrical, cylindrical male flagellomeres that resemble those of Conostigmus ( Dessart, 1983b, 1995a). Members of the D. penmaricus group can be differentiated from Conostigmus by the maximum scape width, which is greater than the pedicel length in D. penmaricus species group members (maximum scape width less than pedicel length in all Conostigmus) ( Dessart, 1995a). The D. punctipes species group is more difficult to distinguish from Conostigmus, but can be differentiated by the combination of the fused parossiculi, absence of the facial pit, and Dendrocerus -like ocellar triangle ( Dessart, 1983b).