Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Coccinellidae

Continuation of this discussion from another forum.

Currently on BugGuide, the taxonomy tree for Coccinellidae is simply:

Coccinellidae
--> various genera
--> Tribe Scymnini

There are no other subfamilies or tribe nodes except Tribe Scymini, and that tribe has no genus nodes (because all the genera are directly under Coccinellidae). Updating the taxonomy tree to include subdivisions between the family and genus levels might be a significant improvement and bring BugGuide's treatment of Coccinellidae in line with that of many other families.

[edit: added this paragraph]
This question was addressed in 2007, and 14 genera (including 7 in Scymninae) have been added to the Guide since then, so it may be worth bringing up again.

There is a detailed, subdivided taxonomy list on the Coccinellidae Info page. It's not up-to-date (Scymninae definitely isn't, I don't know about the rest). Hopefully it can be reviewed, discussed, and updated in this forum. (It doesn't necessarily mean changing the taxonomy tree.)

[edit: removed the Info page taxonomy list to condense space; use the link above to get to it if you're interested]

ton of thanks, Abby---
the new taxonomic arrangement is most helpful indeed!

Nice work, Abigail!
Nice work, Abigail!

 
you're the ones I was waiting for :-)
I know how strongly you feel about keeping taxonomy as flat as possible, and I tried really hard to keep the number of subtaxa down and the genera easy to find. Things were just getting out of control with all those browse pages! (I also read the taxonomy forum back to front this weekend, and oy, I understand why these changes need to take time!)

Comparative taxonomy trees: my biggest argument yet
(Inspired by this comment: "We have been reasonably consistent here at BugGuide of not introducing new taxonomic levels unless the current node has too many subnodes to look at easily in Browse. How many is that? Nothing rigid, but probably around a dozen. Once a family has a dozen genera, people begin to see the need for subfamily or tribe." Also see this comment, which suggests ~15 genera.)

Coccinellidae has 44 genera and 134 species/subspecies (so far) on BugGuide. There are 8 browse pages. There is no other family of beetles with this many genera that does not have subfamilies and/or tribes. There is no other beetle family with more browse pages. Histeridae, the only family with as many browse pages, still has fewer genera and species on BugGuide than Coccinellidae (40 genera, 107 species - it might benefit from subdivision itself).

Moreover, there are families with fewer genera and species (both fewer on BugGuide, and fewer in North America) that do have subnodes. That's not a great argument for creating subnodes elsewhere, I realize, but the precedent exists for creating subnodes for families smaller than, say, rove beetles.

Even more moreover, although one argument against subnodes in Coccinellidae is that the taxonomy is unsettled, the BugGuide beetle taxonomy standard, American Beetles (2002), lists exactly the same 6 subfamilies as Gordon's 1985 "The Coccinellidae (Coleoptera) of America North of Mexico."(1) Other North American subfamilies have been proposed, but literature recently published or in press* by such authorities as Vandenberg (who wrote the Coccinellidae section of American Beetles) has not accepted them. And a 7th accepted subfamily worldwide does not occur in North America. We've still got the same 6 as we did 24 years ago.

Admittedly I do not know what's going on in the unpublished Coccinellidae taxonomy. Still, I doubt that it's going to create fewer genera and subfamilies - can Coccinellidae do anything but become larger and more complex? And even if it doesn't, there are still 15 genera and over 340 species in North America that aren't on BugGuide; the number of browse pages can only go up.

It's simply inconsistent to have such a large family with so many browse pages and so little subdivision. These insects are common, conspicuous, frequently photographed, and therefore the images are often browsed; let's make it less tedious and frustrating to get all the way to the last browse page, and easier to identify the beetles by the consistent anatomy within subfamilies rather than the superficial and extremely variable spots and colors.

*Giorgi, J.A., et al. The evolution of food preferences in Coccinellidae. Biological Control (2009), doi:10.1016/
j.biocontrol.2009.05.019

 
I agree
With so many genera it is time to start subdividing Coccinellidae. When browsing requires so many clicks it is worthless and it will get worse when we keep adding genera (60 in North America). Personally, I would like to see related genera grouped together and I think that this change is way overdue.
Subfamilies could/should be added right now; perhaps, tribes would have to wait until they also became necessary in some of the subfamilies. Scymnini is already there so it should stay there (under subfamily Scymninae).

 
here's my proposal
This is what the tree would look like with subfamilies; no tribes except the preexisting Tribe Scymnini, and subgenera are at genus level. All this is in phylogenetic order, not alphabetical. I'm open to organizational suggestions such as alphabetizing, subgenera, and the placement of Tribe Scymnini (at beginning or end of Scymninae, maybe, instead of between two genera?) Note that this has all 60 genera, not just BG's current 44. I don't intend to create empty genus nodes, just trying to be complete here.
  • Subfamily STICHOLOTIDINAE Weiss, 1901
    • Genus Microweisea Cockerell, 1903
    • Genus Coccidophilus Brethes, 1905
    • Genus Gnathoweisea Gordon, 1970
    • Genus Nipus Casey, 1899
    • Genus Delphastus Casey, 1899
    • Genus Cephaloscymnus Crotch, 1873
  • Subfamily SCYMNINAE Mulsant, 1846
    • Genus Zilus Mulsant, 1850
    • Genus Zagloba Casey, 1899
    • Genus Stethorus Weiss, 1885
    • Tribe SCYMNINI Mulsant, 1846
      • Genus Nephaspis Casey, 1899
      • Genus Cryptolaemus Mulsant, 1853
      • Genus Didion Casey, 1899
      • Genus Scymnus Kugelann, 1794
      • Genus Sasajiscymnus Vandenberg, 2004
      • Genus Nephus Mulsant, 1846
      • Genus Scymnobius Casey, 1899
    • Genus Diomus Mulsant, 1850
    • Genus Decadiomus Chapin, 1933
    • Genus Selvadius Casey, 1899
    • Genus Blaisdelliana Gordon, 1970
    • Genus Helesius Casey, 1899
    • Genus Thalassa Mulsant, 1850
    • Genus Hyperaspis Redtenbacher, 1844
    • Genus Hyperaspidius Crotch, 1873
    • Genus Brachiacantha Dejean, 1837
    • Genus Cryptognatha, Mulsant, 1850
  • Subfamily CHILOCORINAE Mulsant, 1846
    • Genus Brumoides Chapin, 1965
    • Genus Brumus Mulsant, 1850
    • Genus Axion Mulsant, 1850
    • Genus Curinus Mulsant, 1850
    • Genus Arawana Leng, 1908
    • Genus Exochomus Redtenbacher, 1843
    • Genus Halmus Mulsant, 1850
    • Genus Chilocorus Leach, 1815
  • Subfamily COCCIDULINAE Mulsant, 1846
    • Genus Coccidula Kugelann, 1798
    • Genus Rhyzobius Stephens, 1829
    • Genus Rodolia Mulsant, 1850
    • Genus Anovia Casey, 1920
    • Genus Exoplectra Chevrolat, 1837
    • Genus Azya Mulsant, 1850
    • Genus Pseudoazya Gordon 1980
  • Subfamily COCCINELLINAE Latreille, 1807
    • Genus Paranaemia Casey, 1899
    • Genus Naemia Mulsant, 1850
    • Genus Coleomegilla Timberlake, 1920
    • Genus Ceratomegilla Crotch, 1873
    • Genus Hippodamia Dejean, 1837
    • Genus Anisosticta Dejean, 1837
    • Genus Macronaemia Casey, 1899
    • Genus Aphidecta Weise, 1899
    • Genus Adalia Mulsant, 1850
    • Genus Coccinella Linnaeus, 1758
    • Genus Cycloneda Crotch, 1871
    • Genus Harmonia Mulsant, 1850
    • Genus Anatis Mulsant, 1850
    • Genus Myzia Mulsant, 1846
    • Genus Calvia Mulsant, 1850
    • Genus Propylea Mulsant, 1846
    • Genus Coelophora Mulsant, 1850
    • Genus Olla Casey, 1899
    • Genus Neoharmonia Crotch, 1871
    • Genus Mulsantina Weise, 1906
    • Genus Psyllobora Dejean, 1836
  • Subfamily EPILACHNINAE Ganglbauer, 1899
    • Genus Epilachna Dejean, 1837
    • Genus Subcoccinella Huber, 1842

 
Very nice!
I am sure that tribes will be needed soon, also; especially in Scymninae and Coccinellinae.

 
the change is coming, then
Unless someone strongly objects in the interim, I'll do this tonight.

Coccinellinae can't get much more organized than it is now, though - current taxonomy only divides it into two tribes in North America, one with Psyllobora and the other with everything else!

 
Nice
You can add comments to the info page in place of the empty pages to aid in future placement.
Similar to this http://bugguide.net/node/view/94 or http://bugguide.net/node/view/93

Edit: Nevermind I see you already have this.

 
just expanded the existing one
I can't take credit for creating that big multicolor list itself, but I did add the photos and descriptive text. (Actually, just finished adding the last of the photos this morning - I figured that had better be done before I changed the taxonomy tree.)

 
Suggestion
I noticed that the info page had become very "vertical". I would suggest making it more like this page http://bugguide.net/node/view/93
I has all of the text for the genera at the top of the tribes or subfamilies, and then repeats just the genus name and some images, next genus and some images, for the genera currently in the guide. And at the bottom of a tribe if possible references elsewhere to aid in IDing the missing genera.
It is not only less vertical, but has the advantage of lumping images of related genera close together so the similarities can more easily be seen. "Hey my bug looks like those"
I'm not saying it has to be that way, just a suggestion. Also, I'm not saying you should do the work, if you would like my help I'll do it. I can even make an attempt at it and email it to you for approval.
Either way I like what has been done so far!

 
yes, I noticed it was getting long
It started out a lot less vertical before I put the images in! And with only one genus in the Guide for Tribe Sticholo...um, my ability to spell just ran out - well, anyway, it can take up a lot less room. Coccinellinae is unfortunately almost tribeless and includes some of the most familiar species, so that one might still be fairly long, but others can definitely be condensed.

And I appreciate your offer of doing a trial run for me! My e-mail's in my profile, and I owe you a drink next time I'm in Jersey :-)

 
While you are at it
Putting links to the subfamily guide pages would be very helpful too. Just a suggestion.

 
working on it :-)
Started last night, but at midnight my husband reminded me that I did have to wake up at 7 and go to work today...

Another little problem
There is a signata species group under genus Hyperaspis with no images, just some information and listing of species. The corresponding species should be under the group and not outside of it. That is what we are trying to do with Nomada.

latest Scymnini taxonomy (as of Sept. 8 '09)
Posted in another forum by Guy A. Hanley (Sept. 8, 2009), copied here for comparison with BG's list above:

Tribe Scymnini
Nephaspis: four neotropical species
Cryptolaemus: one species
Didion: three species
Scymnus:
Subgenus Scymnus: 11 species
Subgenus Pullus: 82 species
Pseudoscymnus: one introduced species
Nephus:
Subgenus Nephus: one species
Subgenus Sidis: one species
Subgenus Turboscymnus: one species
Subgenus Scymnobius: nine species
Subgenus Depressoscymnus: one species

Current Practice...
as far as I can read the consensus on such debates:

The aim is for an accurate- but flat- taxonomic tree, unless it's unwieldy. New taxonomic levels generally aren't approved unless there are so many lines in the current taxonomic tree that it's hard to find things. The reason is that most people will be looking for a familiar name, and have no clue what subtaxon it belongs to.

In this case, for instance, someone looking at the Coccinellidae tree would have to know that Harmonia is in the Subfamily Coccinellinae in order to get to it without doing a search or "view all".

Sometimes a node is added when people are more likely to be looking for that taxon than the subtaxa it contains. That would probably apply to the Scymnini.

Adding nodes to the tree so it's "correct" or "more consistent" usually doesn't fly.

 
just Scymnini, then?
Okay, I'll sit back down! Just wanted to shift a discussion from an increasingly-less-appropriate forum and summarize that discussion a bit.

I know the Coccinellidae subdivision question has come up before (long before I showed up to bang around in it)- one major discussion was in 2007. Since then, 14 more genera have been added to the Guide, including 7 of the Scymninae, so it seemed worth revisiting.

If it's permitted to move the genera of Scymnini into the Tribe Scymini node, does that mean the tree will have to be like this?

Coccinellidae
--> Tribe Scymnini
--> -->Genus Scymnus...
-->No Taxon
--> -->Genus Adalia...

If only there were a way to get those little brown beetles and their Einstein-haired larvae together without making everything else so difficult...

 
Not so... er... slow...
I didn't say that creating subtaxa in Coccinellidae was impossible. You just need to make your case, and the principles I laid out are the main things to address.

You said it would be an improvement to have subfamilies: why? How would it make the taxonomy tree easier for the average person to use?

As for what the tree would look like if genera were moved to Scymnini: it would look like it does now, except that Cryptolaemus, Scymnus, etc. would no longer show under Coccinellidae. Instead, one would have to click on Scymnini to see them.

Whatever the merits of creating subfamilies, etc., for all of the Coccinellidae, I do think the Scymnini genera need to be moved under the Scymnini node. It's one thing to have unnecessary levels in the tree, but it's another to have a level and not use it. That would be saying that Scymnus, etc. aren't members of Scymnini when, in fact, they are.

 
Genera, tribes
I agree that the genera of the tribe Scymnini should go under the tribe. Keeping the other genera listed in alphabetical order rather than under their respective subfamilies or tribes may be the best way to go right now. But I suspect that eventually we may have to create some intermediate layers, considering that there are 58 genera. An alphabetical list of so many genera instead of a more natural arrangement is undesirable.
As for making the search easier for those who don't know taxonomy, or are not familiar with names, the solution is to have an overview as we have done for several other taxa. You can see the subfamily and tribal groupings and all the genera along with some representative images all in one page.
BTW, Abby, the overview of Coccinellidae keeps getting better and better.

 
Scymnini moved; thoughts of Scymninae
I moved the Scymnini genera into the Tribe Scymnini node, and added some ID information to the Info tab. I'll do an overview sometime this week, hopefully.

It's great to have those little brown beetles and their oddball larvae in one place; I think that digging through the images in Genus Scymnus will turn up members of other Scymnini genera that just didn't have an obvious place to go before.


That still leaves the genera of six other Scymninae tribes directly under Coccinellidae (Brachiacantha, Diomus, Hyperaspidius, Hyperaspis, Stethorus, Thalassa, Zagloba, and Zilus). Many of them are "Scymnus-y" little brown beetles too, and there's probably a similar argument for putting them together as was made for Tribe Scymnini.

How about a Subfamily Scymninae node, instead of Tribe Scymnini? - just rename the existing node, and put all the genera directly under it. I was playing with this on my computer when I was supposed to be working today, here it is w/ the genera in alphabetical order:

Family Coccinellidae
--> Subfamily Scymninae
--> --> Genus Brachiacantha (Tribe Brachiacanthini)
--> --> Genus Cryptolaemus (Tribe Scymnini)
--> --> Genus Didion (Tribe Scymnini)
--> --> Genus Diomus (Tribe Diomini)
--> --> Genus Hyperaspidius (Tribe Hyperaspidini)
--> --> Genus Hyperaspis (Tribe Hyperaspidini)
--> --> Genus Nephaspis (Tribe Scymnini)
--> --> Genus Nephus (Tribe Scymnini)
--> --> Genus Scymnobius (Tribe Scymnini)
--> --> Genus Scymnus (Tribe Scymnini)
--> --> Genus Stethorus (Tribe Stethorini)
--> --> Genus Thalassa (Tribe Hyperaspidini)
--> --> Genus Zagloba (Tribe Scymnillini)
--> --> Genus Zilus (Tribe Scymnillini)

 
Un-backing off now , and another idea
Okay, I'm trying not to stir up a huge ruckus my first week as an editor, that's all :-)

I spend most of my non-Coccinellidae-node time over in Lepidoptera, where there are so many moth subdivisions, and I was comparing Coccinellidae's tree to that - I've done some more poking around, and see that most families don't have those multi-level trees. (I also just discovered "view all" on the tree pages, which is so much easier to navigate!)

Looks like a lot of people are on board with keeping the Scymnini together in their own tribe, and that would be the main improvement I was thinking of - being able to browse them and compare them much more easily, without being distracted by the "typical" (for average users) red beetles with black spots, black with red spots, blue with orange spots...

A thought that wouldn't involve further subdivisions for the other tribes: Instead of having our taxonomy tree order the genera alphabetically, could they be ordered by subfamily and tribe? It would keep a lot of similar-looking beetles together for the average user, and might keep the more taxonomically-minded happier. (Which isn't a scientific argument, I guess, but a general impression from reading comments and moving images to the correct nodes if they've been misplaced or left lonely at the family level.)

Anyway, seems to me that having, say, the genera of Chilocorini grouped near each other (without actually having a Tribe Chilocorini node) would mean that an average person finding a helmet-shaped black beetle with red spots could look at the helmet-shaped black beetles with red spots in Axion, Chilocorus, and Exochomus at more or less the same time, seeing how the anatomy is similar, instead of looking at the superficial color similarity of melanic Adalia bipunctata and Axion (on the same page under the Browse tab), perhaps Chilocorus (three genera later/the next Browse page), but probably not going through 10 more genera and 2 more Browse pages to Exochomus.

I'll be back for more later, my boss has been looking over my shoulder too much. I miss that three-day holiday weekend of dawn-to-midnight BugGuide...