Apodrosus revision

We are published!!!

2010-11-30T09:35:00.000-08:00

Finally I'm pleased to share the publication of this work!
Here is the full reference:
Girón, J. C. & N. M. Franz. 2010. Revision, phylogeny, and historical biogeography of the genus Apodrosus Marshall, 1922 (Coleoptera: Curculionidae: Entiminae). Insect Systematics & Evolution 41: 339-414.
We are the front cover of this issue!

Is done!

2010-06-02T14:26:00.001-07:00

And again, it has been a while since my last post... sorry I'm an abandoner!
Well, this history has finished by now... the article has been submitted for revision inthe journal "Insect Systematics and Evolution", it includes the descriptions, photographs, drawings, maps, phylogeny and historical biogeography of the genus.
I'll let you know if and when it is published.

Preparing the presentation: Does it worth it?

2010-01-12T14:47:00.000-08:00

I'm not sure if it's just me but when I was preparing my presentation for the ESA Annual Meeting, my characters resulted to me so insignificant... it was like all the time I've spent looking at the weevils trying to find characters, recognizing character states, coding, analyzing, thinking about groupings, distributions... in some point all turns so light... as if all the work was not really saying anything...
But you need to stop... if the characters are not which/what you expected, there are several factors influencing your results, but most of all, THOSE ARE YOUR RESULTS and there is nothing you can do about it, just to try to present it as down-to-earth as you can, and in such a way that you feel comfortable with what you are saying and how you are saying it.

This is a link to the presentation:
http://academic.uprm.edu/~franz/publications/Giron-ESA2009-Presentation.pdf

And this is me giving the presentation:

And this is a photo of the "weevil persons" in 2009 meeting:

From left to right: Samuel Crane, James Korecki, (-), Anyi Mazo, John Longino, Juliana Cardona, (-), Sara Pinzón, (-), Horace Burke, Charles O'Brien, Jennifer Girón, Mohammed Hassib, Alida Mercado, Steve Davis, Robert Anderson.
Sorry... I can't remember all the names... as I remember it, I'll replace the (-).

Divergence/Vicariance: not completely convinced

2010-01-03T16:54:00.000-08:00

And the moment to say something about biogeography came!

What could I say??? I think it is because of the school that I had as undergraduate, I cannot say things from which I'm not completely certain/convinced and I need to have arguments to defend what I'm saying.

Biogeographic History of Apodrosus looks to me as too pretentious:

- I'm not sure if we (I?) now know ALL Apodrosus species and how extensive the distributions are. Several species are represented by individuals collected at the same and unique event.

- I was impeded to talk about Bio-geography also because I don't really know about the ecological requirements and limitations for each species; I only know about Puerto Rican species because I've been here collecting them and I now know where I can found which one (there are only 3).

- Now History? please! I don't have (yet) the Caribbean geologic history in my head to try to explain diversification patterns within and among islands... At last, i was in psychological negation to use such a sumptuous title.

Well, what I do know and what I can handle without feel I'm promising too much?

- I have 13 recognizable (and named jejeje) species.

- I have distribution data for all the specimens, that can be traced on a map.

My advisor (Dr. Nico Franz - UPRM) gave me a useful and simple guide of how to do a Divergence-Vicariance analysis without too much to think. At first I just thought "ok, let's do what he said", but the more I advanced in the exercise, the more sense it acquired.

First, for the 20 species I had 17 areas of distribution: the analyses didn't run!

The next logical (?) step was to reduce the number of areas by fusing sectors: I had then 8 areas of distribution that results in 9 dispersion events BUT, not always the sequence of the "dispersion" had a "simple" explanation (which I could handle without thinking in vicariance and extinction). So, fuse areas again!

At the third attempt I had 5 areas (which couldn't be amalgamated in a merely geographic sense without appear arbitrary). The analysis resulted in 5 dispersion events, that are understandable without too much history involved (overall taking into account I had no time to learn about Caribbean geological history at that moment).

This is an image of the results:

- A map (courtesy of Google maps) with the five defined areas :

- Central America - Hispaniola - Puerto Rico

- The Turks and Caicos Islands - The Bahamas

- A taxon/area cladogram in which the branches correspond to species and colors to areas.

- An area cladogram without geological time incorporated, just to show the dispersions.

If we incorporate geological history, the cladogram will tell if the current distribution is explained for vicariance, dispersals, extinctions... that would be really informative!

Rushy/obligate baptism: no more delay!!!

2010-01-02T15:15:00.000-08:00

And then, it turns out that I had to baptize my species before the presentation instead of leave them as sp. 1 JCG, sp. 2 JCG, etc (the code adopted in the beginning of this history)... nobody knows how much I broke my head thinking in appropriate names... because they will last more than I in this planet/history-sequence, and because MY weevils as beautiful as they are, deserve at least pretty names I think...

Anyway, I have to recognize that I have the trend to delay things... maybe is just a matter of custom... so, it was the last week before the meeting in which a kind of inspiration invades me and I decided to name the species according to their coloration pattern (in most of the cases) because it is quite distinct but is not easy to code as a character... also because as a good Colombian, I work better under pressure...

The names are:

Apodrosus eximius (meaning uncommon) because it was the species with the lowest number of specimens in our field trip across the Dominican Republic.

Apodrosus artus (meaning narrow) in reference to its narrow body shape compared to the other species.

Apodrosus andersoni, named after the weevil specialist Robert Anderson (Canadian Museum of Nature) who has helped me a lot from my beginning as a "weevil person"

Apodrosus earinusparsus (earinus - green; sparsus - sprinkled) because of the coloration of the scale coverage.

Apodrosus epipolevatus (epipole - surface; levatus - raise) because of the elevations of the elytral surface.

Apodrosus mammuthus from mammuth (large), its the largest species.

Apodrosus viridium (viridis - green; ium - diminutive suffix) a small and green species.

Apodrosus stenoculus (steno - narrow; oculus - eye) with narrow eyes in lateral view, compared to all other species.

Apodrosus quisqueyanus for Quisqueya, the name for the Hispaniola island in Taíno language.

Apodrosus empherefasciatus (emphere - apparent; fasciatus - striped) because the elytral scales are slightly darker in interspersed intervals, appearing lightly striped.

Apodrosus adustus (meaning brown, tanned) because of the predominant dorsal brown coloration.

Well, it wasn't easy to choose, but a kind of interesting and funny, and I'm happy with the names now jejeje!

Playing and lightly lost between characters, states, optimizations and trees: almost satisfied

2009-12-18T11:09:00.000-08:00

So, the first attempt could have been worst but still was not good, then the game of get things (taxa/characters) in and out began!

The matrix had 41 characters for 22 taxa:

Experiment 1. Without Anypotactus: Take all Anypotactus out would obligate me to found more characters... Not fun... so, I took the one with lowest level of noise (inapplicables) and also would allow to polarize some characters:

The result: one single Most Parsimonious Tree (MPT): L=173; CI=41; RI=63

Anypotactini grouped: Good

Polydrusini -Outgroup- grouped: Good

Anypotactini + Polydrusini -Outgroup- forming a sister clade for Apodrosus: Interesting...

sp. 6 JCG and sp. 13 JCG grouped: Good

Really not convinced about groupings within Apodrosus...

Some character coding had to be changed (reductive coding), some characters became uninformative...

This are images of my notes about that

The game continued until the final matrix was ready -I must confess that it was in part because of the low rate of will reached at that point and because there were discussions, analyses and a presentation remaining to be done before the ESA annual meeting-

This is the last version of the matrix and the single MPT that it produced (L=76; CI=42; RI=69):

The Outgroup has a "rare" distribution (it doesn't matter now)

Anypotactus bicaudatus is the sister taxon for Apodrosus clade... jum... interesting!

sp. 6 JCG and sp. 13 JCG were excluded because there are several characters that group them and I still don't know how to decide if they belong to another different and surely new genus.

Now I'm comfortable with the groupings within Apodrosus!

The names?? uh... let's decide after...

Character coding

2009-12-16T20:31:00.000-08:00

Then, there I was, wondering about differences, how to call those differences, how many and which states to code...

This was the initial matrix... Notice the name of the file (Apodrosus.winc) and the names of the species: they are going to change briefly. The Anypotactini are shaded in purple, the Polydrusini in blue and in green, two "Apodrosus" that are very different from the rest, and similar between them: still not sure about who they are.

9 outgroup taxa, 2+9+2 ingroup taxa, 29 characters:

Analyze => Heuristics: Hold =2000; mult*100; hold/100; mult*; max* => apo_1.tre: one most parsimonious tree completely resolved (L= 173; CI= 37; RI= 51).

A rare result, with really bad statistics:

Anypotactini grouped: Good

Polydrusini -Outgroup- grouped: Good

sp. 6 JCG and sp. 13 JCG grouped: Good

Why argentatus is the sister group for all???

What is sp. 11 JCG doing being grouped with the Anypotactini???

There's no coherence between this tree and what was supposed to happen... there is something wrong, this is not what I expected...
As with most things in life, it couldn't be perfect the first time.

Outgroup selection

2009-12-16T19:28:00.000-08:00

If you ever thought that selecting an external group for a phylogenetic analysis is an straightforward task let me warn you that you're wrong!

According to the genus' author, Apodrosus is a polydrusine closely related to Polydrusus. If you read one of the previous post about Polydrusus, you'll see that it is an entanglement of hooks...

A year ago I consulted Dr. Nikolai Yunakov, from the Russian Academy of Sciences who have worked with Palearctic Polydrusus; he told me that I should look for american species, so I did. I decided to include other polydrusines as Cautoderus and Polydrosodes that are distributed in Central America, in fact Charles O'Brien -curculionid specialist- suggested me that Polydrosodes could be closer to Apodrosus than Polydrusus.

Additionally as I had some experience with other entimine groups, I noticed the resemblance of Apodrosus with Anypotactus that belong to a different tribe, the Anypotactini; I also included another genus known to me -and very different from Anypotactus-, that is also present in the Caribbean: Polydacrys.

I also included one species of Sitona that is supposed to be the farthest relative among the outgroup.

This way, I prepared the dissections for 9 outgroup taxa, in order to choose and code the characters. I really didn't knew how many surprises were waiting for me...

Let's see... where am I?

2009-12-16T19:26:00.001-08:00

Ah, ok!I've made really good progress -wait... it has took too much time... anyway-

Now I have the genus re-description, the re-descriptions for the 2 known species and also the 11 new species.

Also I've performed phylogenetic and divergence-vicariance analysis (hopefully, I'll post it soon)

I've presented this results at the ESA meeting in Indianapolis this week with really good comments about it! :D

Let's establish a sequence of updates:

- Outgroup selection

- Character coding

- Playing and lightly lost between characters, states, optimizations and trees: almost satisfied

- Rushy/obligate baptism: no more delay!!!

- Divergence/Vicariance: not completely convinced

- Preparing the presentation: Does it worth it?

- Next steps
I think that's all for now. Ok, I'll tell you!

Promise

2009-12-16T18:41:00.000-08:00

Something unexpected has happened: it turns out that this blog actually have a follower (besides of my lab partner Juliana who is not a big fan of this kind of "exhibition") and I've met him at the Weevil informal meeting at the ESA meeting in Indianapolis.

He noted that I've almost abandoned this blog so I've promised to post something and I will!

Thanks James Korecki (USDA-APHIS-PPQ)!!! you made me realize that this kind of information sharing actually works!

Aedeagus

2009-05-01T14:59:00.000-07:00

Here are some images of the aedeagus of the Apodrosus species. As you can see, there is three different 'schemes', one of which is shared by three of the species. In some cases has been difficult to describe the apex and the sclerites of the internal sac of this structure.

There remain three new species for describe, two from the Dominican Republic and one from Haiti. I'll be working on build the genus description in order to cover all the variations found and to get a particular set of characters for each species. I hope to finish before may 20... let's see...

Baptism

2009-03-08T12:37:00.000-07:00

Last days I've been thinking about names for the new species. It was a little complex to decide if name for morphological conspicuous characters, by the place in which the species was collected or in honor to someone.
After thinking about the collecting experience in Puerto Rico and the Dominican Republic, I've decided to name one species for the collecting place, which is the highest elevation of P.R.; another one for the collecting place, named in honor to a Taíno Cacique; another one which was founded in different collecting places through D.R., will be named for the Taíno name of the island; another one for its green coloration; the species from Bahamas, for its coloration too.
If the names are approved, I'll let you know!

Comparative descriptions

2009-01-27T13:03:00.000-08:00

Recently I've "finished" the Apodrosus argentatus morphological description and I'm using it for describe A. wolcotti. When changes are being made, it is necessary to go back into A. argentatus traits. This way, new characters are appearing by comparison. The problem, maybe you can become excesively meticulous on the descriptions... but really, until now I can't know when stop!

Here a sample of "new" characters: Male tergites VII & VIII; Sternum VII

Anterior and posterior margins, the sculpture of surface, the projections... all are becoming important because they vary, but only by comparison it is clear.

ESA 2008

2009-01-27T12:30:00.000-08:00

After too much time, finally an update to this blog!

Here are a picture of me with the poster that I've presented at the ESA meeting in Reno NV, last november.

If you want to see a PDF of the poster, you can go to: http://academic.uprm.edu/~franz/publications/Giron-ESA2008-Poster.pdf

Spermathecae

2008-10-27T12:19:00.000-07:00

Here are photographs of the spermathecae of the two described and six new species of Apodrosus.

New species

2008-10-25T15:55:00.000-07:00

This week I've review the Apodrosus specimens from UPRM collection and CWOB loan.
The specimens were sorted having in account characters as:

Extension of median furrow
Projection of eyes in dorsal view
Width of frons
Extension of scrobe and antennal scape
Surface of elytra
Separation of elytral striae IX and X
Coloration of scales

Based on those criteria, between others, nine species were cataloged and prepared for dissection of terminalia, excepting sp. 7 JCG, because there is only one male and one completely sclerotized female.
When dissections were done, we have five definitively new species of Apodrosus:

sp. 1. JCG: Puerto Rico, Cerro de Punta - UPRM
sp. 2 JCG: Bahamas, Andros Is. - CWOB
sp. 3 JCG: Dominican Republic, Independencia - CWOB & UPRM
sp. 4 JCG: Dominican Republic, Peravia - CWOB
sp. 5 JCG: Dominican Republic, Pedernales - CWOB & UPRM

sp. 7 JCG was not dissected
sp. 8 JCG corresponds to A. argentatus
sp. 9 JCG may correspond to A. argentatus, but needs a detailed comparison.

* sp 6 JCG is not an Apodrosus, but can be closely related.

Schemes of aedeagus and espermatheca would be prepared soon in order to include it in the poster for the 56th ESA meeting in Reno.

What I'm doing now?

2008-10-08T13:20:00.000-07:00

On the summer, the Franz lab went to the Dominican Republic in a collecting trip across the country. 61 localities were visited looking for entimines (and other interesting insects) and almost always this weevils were located.
The collected material was brought to the UPRM Invertebrate Collection, where this was sorted, mounted and labeled and is ready to be identified.
In the collecting and sorting process, weevils belonging to Apodrosus were recognized (a time ago the specialist Charles O'Brien told us about new species of Apodrosus from the Dominican Republic and the Bahamas; we are already borrowed this material from him).
At this moment at least five new species has been separated and cataloged in a database of the collecting localities.
These are the next objective of the project, but at the moment, the morphology is being reviewed as a necessary step before to deal with the new species description.

The begining of the revision

2008-10-08T11:12:00.000-07:00

Early this year I began the revision of Apodrosus, reviewing the original descriptions of the genus and their species, examinating characters/specimens and making dissections trying to separate possible morphs inside A. argentatus. Some observations made at that time:
- Mandibular scar is reduced and shallow.
- Mouthparts correspond to phanerognathous type (as in Polydrusus), but it wasn't mentioned in the original description of the genus (I need to find the original description or a revision of Polydrusus).
- The elytral striae IX and X could be separated or fused at second third: in the description of A. wolcotti (type species), says that striae IX and X coalesce in the middle for one-third of their length, which is not true for A. argentatus. The same happens with a prominent posterior callus (at apex of fifth elytral interval).
- The corbels should be carefully observed.
- The surface of tergite VII have two lateral strigulate stripes
- There is a medium apodeme at apex of sternum V
- The apex and teeth on the internal membranes of aedeagus and the shape of spermatheca is different between species (confirming the usefulness of these characters in separating species)
- There is an undescribed species collected at Toro Negro (Puerto Rico), that presents the main characters of the genus (see Until now... in this blog), but is smaller, the shape of the head is different from the other species and their dorsal surface can be described as tubercled.
Some SEM pictures of the head was taken.

About Polydrusus

2008-10-08T07:21:00.000-07:00

I do not have enough information about Polydrusus yet. For now, all I know is that it is a widespread genus mainly Palearctic, with about 188 described species from which 24 are recorded from the New World -11 from Mexico and Central America; 3 from South America (Argentina and Chile); 2 from the West Indies; and 8 from North America -.
Until now, I just have seen specimens of few American species:
P. americanus (USA: WV)
P. cervinus (USA: ME)
P. chlorogaster (El Salvador: Cerro Verde)
P. conicus (Mexico: Michoacán)
P. impressifrons (Canada: Ontario)
P. mutabilis (Costa Rica: Heredia)
P. nothofagi (Chile: Aisén)
P. partitus (El Salvador: Montecristo)
P. peninsularis (Mexico: Baja California)
P. roseus (Chile: Cautin)
P. sericeus (USA: MA)
From a general examination I can say that Polydrusus is an extremely variable genus, overall in head characters. In general, all have small size (between 3 and 8 mm) connate claws, phanerognathous mouthparts and slender antenna.
Coming soon, I will make some dissections to find out shared characters between Apodrosus and Polydrusus.
Image from: http://magickcanoe.com/beetles/polydrusus-1-large.jpg

Until now...

2008-10-08T06:46:00.000-07:00

Apodrosus is a genus of Entiminae weevils (Coleoptera: Curculionidae), that contain just two species reported from Puerto Rico: A argentatus and A. wolcotti.
It was described by Marshall in 1922, closely related to Polydrusus Germar 1817, in the Polydrusini tribe (sensu Alonso-Zarazaga & Lyal 1999).

The main features include small size (5 to 7 mm), connate claws, a long, deep median furrow on the head and a large, bare, smooth triangular area formed by the epistome.
Recently some species belonging to this genus has been collected in the Dominican Republic, but these does not pertain to the described species. These new species are waiting for be described.

This revision will be the first chapter of my Master's thesis. It includes redescriptions of the known species, descriptions of the new ones, all including a complete set of morphological traits, not just external, but also characters of mouthparts and terminalia. Those will be made by built a database in DELTA. Additionally, this work will contain habitus pictures, drawings of structures and SEM pictures. Finally, a dichotomous key to the identification of the species will be constructed and a phylogenetical hypothesis will be proposed.