This genus, and the following one (Poecilognathus) are sometimes easily separated and sometimes not. The use of phenotypic and structural characters mentioned in different source materials sometimes lead down different paths. For example, Evenhuis' loewi group, which he places in Poecilognathus, displays most characters of Neacreotrichus as per Hull (1973). Until more research is completed and until DNA examination says otherwise, we are placing individuals without right-angle third submarginal veins and also lacking stump veins in the genus Neacreotrichus. This may mean that the loewi group is better placed in this genus. One other unresolved issue has to do with antennal length. In all members of both genera, the antennae are long. However, in most specimens with Neacreotrichus venation, the 3rd antennal segments are usually linear and, in both sexes, fully 4 or more times the combined lengths of segments 1 and 2. On the other hand, specimens with Poecilognathus venation typically but not always have shorter, more rounded 3rd segments in both sexes, at times barely twice as long as the combined lengths of segments 1 and 2. At this point, it is not known if this is a species-level distinction or whether the exceptions are unspotted Poecilognathus or more properly placed in Neacreotrichus. With flights usually from mid-summer through early fall, adults are regularly on the wing very early in the day, sometimes by 6 am. But some individuals have been found as early as March and fly during the heat of the day.  On occasion, adults have been caught in flight traps of various sorts.

Identification to species level is poorly known in both genera. One cluster of species here placed in Neacreotrichus, is entirely black, a second group has black and white abdominal rings, and yet another has a mostly yellow abdomen with longitudinal stripes on the thorax. At least in part, members of this latter group have been referred to as N. diversus.  And still another phenotype that may be something called "consors" has a yellow patterned abdomen with a dark shield-shaped blotch on the thorax.  And finally, if "loewi" types, those formerly placed in Poecilognathus by some, are included here in Neacreotrichus, they can be recognized by the pale-striped thorax and mostly yellow abdomen.  At least 6 possible species - consors, humilus, loewi, melanoscutus, picturatus, and vittiventris - have been cited from Arizona.  All known phenotypes, which may or may not match up with these names, are shown here.  As mentioned elsewhere, we assume that future work with DNA will shed significant light on the systematics of problematic genera such as this one.