Fieldwork in South Africa - "coffee is coffee, tea is tea"

This is a quick post, on the urging of Simon, about a recent collecting trip to Limpopo province in South Africa. My co-conspirators for this trip were from the Brakefield lab in Cambridge: Erik van Bergen:

Erik with his first-ever wild-caught butterfly, a Papilio demodocus

and Oskar Brattstrom:

Oskar in typical pose and attire

The aim of our trip was to capture live females of Papilio dardanus (the  most interesting butterfly in the world), along with various Bicyclus species. The trip came out of a workshop held in Ghana on Afrotropical Lepidoptera research. There, Oskar and I met several extraordinarily interested members of the Lepidopterists' Society of Africa (seriously, go there and join), among them Bennie and Andre Coetzer who, after hearing about the butterfly projects in Cambridge (and over many beers) insisted that we visit them in South Africa and they would show us a site "where you could pick the butterflies off the trees with your fingers."

|Andre (far left) and Bennie (next to Andre) Coetzer in Ghana

After our return to Cambridge, it didn't take long to commence planning on the South Africa trip.

Upon arriving in Johannesburg, and picking up our loyal Josephine from Avis, we were treated to some incredibly warm hospitality from the Coetzer's, before striking out for Limpopo. After a braai (and a little too much fine Windhoek draft) at Nwanedi resort, it was time to get into the field! Our hosts had talked up Mphaphuli (our field site) quite a lot, but we were happy to see it didn't disappoint!

Aside from an absence of Bicyclus ena, all the other species we were hoping for were present in abundance, although, given the goals of Erik and I of establishing cultures of butterflies in the UK, there was a slight lack of females (in butterflies, it is usual to observe an excess of males in the field, given the shy and cautious behaviour of female butterflies). Oskar, seeking only pheromone samples, completed his fieldwork rapidly. 

Keeping the butterflies alive in our accommodation proved to be a little trickier, however. I settled on a regimen of twice-a-day feeding of all captive swallowtails, and leaving them in cages at the field site wherever possible. Despite the high mortality of captured swallowtails (not that surprising given their short life expectancy as adults), I was able to get many many eggs by putting cages with mated females onto host plants.

Quenching the thirst of butterflies and scientists alike

Hand-pairing of Papilio dardanus

Mphaphuli proved so productive that we were able to give ourselves a day to see some other zoology in the Kruger National Park:

Oskar's camera is way better than mine

Too too funny to not include.

After packing up and heading home, it did indeed prove possible to get some livestock established in the UK. I'll try and persuade Erik to write something about the Bicyclus, but from my point of view, although only a minority of the eggs I had hatched, enough larvae have survived to do some crosses and I have eggs again (one generation out from the wild)!

The only minor downside from the trip was that one day after returning to the UK, I started to develop symptoms of African tick-bite fever. 

In conclusion, the trip was a roaring success and I owe a great deal of thanks to Oskar, Erik, LepSoc Africa and the Coetzer family.

"I hate my job"

How to make a (real) butterfly out of paper

The instructions for making an origami butterfly could be sketched on the back of the page it was folded out of, but how long are the instructions for making a real butterfly?

The life recipe of a butterfly, the DNA sequence of its genome, is about 280 million "base pairs" long. The art of origami might offer a means to put this number into perspective. Cambridge scientist Alex Bateman has developed an origami model of the DNA "double-helix". So now, rather than making a paper butterfly, we can try to figure out how much paper we'd need to create the complete DNA sequence of a real one.

In a recent record-breaking feat, Dr Bateman lead the construction of a 247 metre long paper DNA strand. This model represented about 10,000 base pairs, only a tiny fraction of a genome. A complete butterfly genome made in this way would require 25 million sheets of paper and would easily stretch across the Atlantic. The human genome, which is more than ten times the size, would wrap around the world three times!

Of course this is a huge-scale model, and in reality the human genome, stretched out in one long line, would be a few metres in length. Also, the genome is not a single DNA strand - it is divided up into 23 chromosomes (21 in a butterfly). Still, it is remarkable that all of this DNA (in fact two copies of each chromosome - one from each of our parents) is crammed into every single living cell in our bodies.

Mendeley

To organise my collection of papers and references I use the reference manager Mendeley.

Mendeley is a desktop application (very similar to Mekentosj Papers in this respect), a cloud-based community for backup, storage and sharing of papers and a scientific social network (a bit facebook, a bit LinkedIn).

The desktop application curates your collection of pdfs:

The panel on the top left contains your list of folders and public groups (see below for more on these), the bottom left panel enables you to search by author, author's keywords, journal or personal tags in your tag-cloud. The middle panel displays the documents in whatever folde is open and the right panel shows the metadata for the selected paper (title, author, tags, abstract etc.). Clicking on the pdf symbol next to a reference opens the reading screen:

Here you have the option to read fullscreen, as well as edit metadata on the right as well as highlight and annotate the paper itself (very handy!). Mendeley tabs all the references you may have open at any one time, making it simple to flip between them.

Importing papers is simple. You can either drag a pdf into your libary or select the 'Add Documents' button in the library screen. Mendeley then adds the pdf to your library, checks for metadata and automatically fills out Title, author, publication etc. This isn't perfect but it nearly always works and is improving - it's simple enough to edit incorrect entries: Mendeley lets you search Google Scholar with the title to fill out these fields if it can't find the reference in its catalogue. Best of all, Mendeley copies the pdf into a folder in its area of your hardrive and renames it in a format of your choosing: 'j.1365-294X.2011.05127.pdf' now becomes 'Legrand et al 2011 Molecular Ecology.pdf' for instance. These are stored in nested folders with a structure of your choosing.

This is all fantastic, and the cross-platform nature (there are Windows, OS X and Linux versions of Mendeley Desktop as well as iPhone and iPad apps to read your papers on the move) beats all competition hands-down, but Mendeley really comes into its own with its use of the cloud. Firstly, Mendeley allows you to sync your files between multiple computers - just click 'Sync' in the desktop app and all your references are downloaded. Amazing - no more carting around an external hard drive full of pdfs so you can work at home.

Mendeley is also great for collaboration: you can search for other users by email address and add your colleagues. You can then make groups or shared folders of references (complete with a facebook-like wall for discussion) with your collaborators. I use this feature to help run our journal club - it works brilliantly!

Finally, you can make a public profile to go with your Mendeley web presence:

Neat. This will make it easier for my colleagues to find me and share references.

Mendeley also does citation management. You can either export folders as Bibtex lists, copy and paste individual citations from the software itself, or install the plugin for Microsoft Word or Open Office. This lasst option is so easy to use its unreal. In Word:

Alt+M brings up a dialogue box where you can search your library

Select the appropriate reference and it is added. When you've finished the document, use the insert bibliography option in Word:

Very cool. The reference style is customizable too. 

Thinking about Acraea again today

Female Acraea jodutta

Keep thinking about Acraea species. They're Mullerian mimics from Africa, and often the models for Papilio dardanus. Some are sympatrically polymorphic, some sexually dimorphic and some are infected by Wolbachia male-killers.

"The most interesting butterfly in the world"

Female Papilio dardanus, form hippocoonides

Sex mosaics

This is a sex mosaic ('mosaic gynandromorph') Papilio dardanus from our breeding experiments last summer. The left wing is mostly the pattern of the female form cenea, but the right wing shows lots of yellow patches of male pigment. There is even a segment at the bottom corner with male patterning and even a little bit of a tail.

P. dardanus male

P. dardanus female, form cenea

It is thought that this kind of pattern arises (in Lepidoptera at least) from the loss of one of the female-specific sex chromosome from one of the two daughters of a cell division, or possibly when meiosis goes awry and the egg contains an incorrect number of sex chromosomes. 


In butterflies and moths, the sex determination system is the other way around to humans - males have two identical sex chromosomes (ZZ rather than XY) and it is the females with two different sex chromosomes (ZW contrasting with XX in humans). If this loss happens very early in development whilst the embryo is only a few cells, the result can be a striking bilateral gynandromorph:

Papilio dardanus bilateral gynandromorph - left side female form cenea, right hand male

However, if the error occurs later in development, the result will be a mosaic as in the first picture. Isn't biology cool?!