And all the more remarkable that on the other hand, the clypeus (the sclerite on lower part of face, above the mandibles) has a complete black stripe.
There is no (e.g. subspecific) systematically recognized difference between this kind of pattern and the darker ones lacking the "arrow". In fact, yellow color on T1 has two distinct parts: the "normal" apical stripe and two spots "inside" the black basis, homologous tho those on T2.
And these two spots can be so small they are barely visible, sometimes lacking altogether. By contrast, they leave only a central black "arrow" when they are well developped, merging with the apical stripe.