Fungus-eating lady beetles

I got a start on tackling verification of IDs for this genus, but got stuck:

There's this handy guide, but it appears to be more challenging than what the guide shows:

Especially out in California, where the twenty-spots look like the kidney-spots to me.

@silversea_starsong, can you help clarify the distinguishing features?

Posted by pfau_tarleton pfau_tarleton, August 09, 2017 13:02


The bugguide page references this book, which is available in full online:
I did a ctrl-F search on Psyllobora and found the figures illustrating the species:

Looks like this is one of those cases where you need to look at genital structure to ID if the markings are too similar.

Posted by nanofishology almost 5 years ago (Flag)

Genitalia is only required for 1 in a few hundred specimens. The two species are remarkably different once you are used to them. I have personally not encountered a specimen where genitalia were necessary.

In California the ID is easy because there 20-maculata has a special form with both brown and black markings simultaneously (what I refer to as "bicoloured" in my notes). Renifer has only black or brown markings, not both.

Outside of California where both species have only black markings, you can look at the side spot. This spot is usually reduced or entirely missing in renifer, while it is complete and well present in vigintimaculata (including the CA form).

The actual marking formation overall is different too but its hard to explain those differences without practice.

Posted by silversea_starsong almost 5 years ago (Flag)

Bugguide has no real information on the ID. I'll fix that page at some point.

I made a post for someone else on this site last time, that might give you more insight:

Posted by silversea_starsong almost 5 years ago (Flag)

Thanks yall! What excellent work you've done, James! Johnny Nash's song, I Can See Clearly Now, is playing in my head.

Posted by pfau_tarleton almost 5 years ago (Flag)

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