From Kingsolver 2004 (1), Z. spectabilis and the male of Z. cruciger have similar markings. Both have white markings on their lateral pronotum. Both also have sutural stripes the on pronotum and elytra, which the female of Z. cruciger lacks. They are most ready distinguished by their great difference in size. Z. spectabilis is only 0.7-1.6 mm, while Z. cruciger comes it at a whopping 2.1-2.9 mm. The subject specimen is reported to be 2 mm. This is more consistent with Z. cruciger, but is just a round number.

I have posted an image series on a beetle which, at 2.76 mm (with head retracted), is more clearly a Z. cruciger male showing these features:

The remarks there go into more detail. The same uncertainty applies to this Zabrotes sp. that was thought to be Z. spectabilis.

but I'm not sure if it is Z. cruciger?

a pygidium closeup would help a lot

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