Colour matching feature in R

I love R. It is an open-source statistical programming language that I found reasonably easy to learn, and find it incredibly versatile and useful. Because it's open-source anyone can contribute to it, and there are a huge number of packages that extend its capabilities to do pretty much anything.

I've been using it to do Principal Components Analysis on some colour data that I measured from photos of some Carpophilus specimens, and was trying to figure out how to relate the RGB values I got from the photos to actual names. R has in its core packages a colors() function with a lot of names assigned to particular RGB values. Thankfully, Barry Rowlingson has come up with a very nice little function that figures out which colour names the RGB value is closest to:

nearColour <- function(r,g,b){
 ctable = col2rgb(colors())
 cdiff = ctable - c(r,g,b)
 cdist = cdiff[1,]*cdiff[1,]+cdiff[2,]*cdiff[2,]+cdiff[3,]*cdiff[3,]
 return(colors()[cdist == min(cdist)])
 }

Pretty useful for standardising colour names!

Pacific Science issues online

Pacific Science is a quarterly journal published by the University of Hawaii Press in conjunction with the Pacific Science Association. First published in 1947, it is one of the longest running peer-reviewed science periodicals that is focussed primarily on the South Pacific region. As such, it is an excellent resource for those of us interested in the region.

PDFs of all back issues published prior to the year 2000 are available free of charge from this website. Unfortunately, the search function leaves a lot to be desired, but it is extremely useful if you know what you're looking for, and very interesting to have a browse through.

Biologia Centrali-Americana online version

The full text and plates of Biologia Centrali-Americana can be found online here. While it's not Pacific-focussed it is an extremely interesting and informative document with a whole lot of valuable plates, such as this one. With three volumes worth of weevil stuff, and a decent section on Carpophilus, I will be spending a bit of time here I think...

While on the topic of Caribbean fauna, Father Sanchez's website has a lot of very good photos of a huge range of the flora and fauna of the Puerto Rico. He's a Catholic priest, and his passion for both Christ and nature is really inspiring.

Pacific species described in Genus

Eastern European taxonomists are prolific. Over the past couple of years, a few have described a fair number of Pacific Island species of scydmaenid leaf beetles, jumping spiders in the journal Genus, published by the Polish Taxonomical Society.

These include nine species of Galerucinae from New Caledonia, the jumping spiders Lagnus monteithorum from Fiji and Phintella caledoniensis from New Caledonia, and thee scydmaenid beetles from New Guinea: Paraneseuthia guineana, P. devia and Cephennodes papuanus.

All of these papers are rather standard and dry (unless you're really into the taxa!) taxonomic papers, but there's some pretty cool photos in the spider papers....


References:
Beenen R. 2008. Contribution to the knowledge of Galerucinae of New Caledonia (Coleoptera: Chrysomelidae). Genus 19(1): 65-87

Jałoszyński P. 2008. First record of the occurrence of Eutheiini and Cephenniini in New
Guinea, with descriptions of new species of Paraneseuthia Franz and Cephennodes Reitter
(Coleoptera: Scydmaenidae). Genus 19(1): 37-44

Jałoszyński P. 2009. Paraneseuthia guineana n. sp. from Indonesian part of New Guinea
(Coleoptera: Scydmaenidae). Genus 20(1): 23-26

Patoleta B. 2008. Description of a new species of Lagnus L. Koch, 1879 from Fiji archipelago (Araneae: Salticidae). Genus 19(4): 717-720

Patoleta B. 2009. Description of a new species of Phintella Strand in Bösenberg et Strand, 1906 from New Caledonia (Araneae: Salticidae). Genus 20(3): 539-543

Bat flies of the Pacific

I didn't realise that there were bat-flies in the Pacific. I had never actually thought about them until I came across an old paper by one B. Jobling in the library on the bat fly family Streblidae. Turns out, there's a good number of species in the region: 15 according to the Australasian and Oceanian Diptera Catalog. Some of them have rather large ranges--Brachytarsina amboinensis is found from India and Okinawa, through the Philippines and Indonesia to Australia and New Caledonia.

While it seems that for the most part, bat flies tend to move from host to host with abandon, there are some which are only found on a single bat species. Brachytarsina buxtoni from Fiji and Samoa is only found on Emballonura semicaudata, while B. rouxi from New Caledonia is only found on Notopteris neocaledonica. Jobling reckons this is because these bats roost separately, preventing these species from colonising other bat species.

References:
Jobling B. 1951. A record of the Streblidae from the Philippines and other Pacific Islands, including morphology of the abdomen, host-parasite relationship and geographical distribution, and and with descriptions of five new species (Diptera). Transactions of the Royal Entomological Society of London 102(4): 211-246

Featured insect: Eucurtiopsis kitchingi (Coleoptera: Histeridae)

It may be difficult to tell, but this is actually a beetle. More specifically, it goes by the name of Eucurtiopsis kitchingi and is in the subfamily Chlamydopsinae of the Histeridae. It was very recently described (in September) by Alexey Tishechkin from material collected during the Santo 2006 expedition. Doesn't it look cool!

The Chlamydopsinae are an interesting group. Shunning the scavenging and predatory stereotype that the histerids have, the chlamydopsines cohabit with ants and termites, where they might feed on eggs and larvae. One species has also been observed riding on top of their host ants as a means of transport. Until recently, they were considered to be a relatively species-poor group, with only 47 species in 1997. However, the past 10 years has revealed a startling amount of diversity, particularly on the Pacific Islands of New Caledonia and Vanuatu, and undoubtedly with more to be discovered in other regions also.

Unfortunately, nothing is known about the biology of E. kitchingi. It was collected in flight intercept traps, and was not detected in any of the ant nests the author investigated. At 1.5 mm in length, it's not going to make its presence felt, and is unlikely to be found serendipitously. This being said, ant research is an active area currently, and so it might pay for ant workers to keep these beetles in mind as they do their field work.

References:
Caterino MS, Degallier N. 2007.A review of the biology and systematics of Chlamydopsinae (Coleoptera: Histeridae). Invertebrate Systematics 21: 1-28.

Tishechkin AK. 2009. Discovery of Chlamydopsinae (Insecta, Coleoptera, Histeridae) in Vanuatu with the description of eight new species from Espiritu Santo Island. Zoosystema 30(3) : 661-690.

Fire ant origins and genetics

The fire ant Wasmannia auropunctata is one of the most annoying things in the Solomon Islands. They have a very irritating and itchy bite, are so small as to be invisible, and they have a penchant for living in your underwear draw. Not pleasant. Unfortunately, they are another of the invasive species that have invaded the islands from elsewhere, in this case South America. They are found naturally through a large part of South America, from Argentina to the Caribbean islands. They have been introduced to a number of places, including Hawaii and the United States, Gabon in West Africa, and in the South Pacific both the Solomon Islands and New Caledonia.

To investigate where these ants came from, Alexander Mikheyev and Ulrich Mueller conducted a genetic study on a bunch of both natural and introduced populations of the fire ant. Looking at a little bit of the mitochondrial COI gene, they discovered that the Solomon Island populations have affinities with US and Hawaiian, and Northern South America and Caribbean populations. New Caledonian specimens were quite different, originating from southern natural populations in Argentina and Brazilian populations. Gabon has also been invaded by this group. This suggests that the two Pacific populations sampled were independantly derived, probably through trade or troop movements during WWII.

An assumption that I've usually made with invasive species in the Pacific is that they tend to do a bit of island-hopping, and in this case I would've hypothesised that the New Caledonian and Solomon Island populations would be the same. This is obviously not the case here, and it is a reminder that it's worth keeping in mind that there are many ways for organisms to get from place to place.

References:
Mikheyev AS, Mueller UG. 2007. Genetic relationships between native and introduced populations of the little fire ant Wasmannia auropunctata. Diversity and Distributions 13:573-579.