Systematics of South Pacific sap beetles

The species of Carpophilus of particular interest: dorsal habitus above, male parameres below.

Two and a half years ago, I completed my MSc looking at the sap beetles in the genus Carpophilus. In particular, I looked at the C. oculatus species complex from the South Pacific. The species was first described in 1864, before it settled into obscurity. It was only mentioned a few times in the literature until 1993, when Ron Dobson published the results of a study where he looked at a large series of the species. He described three subspecies, two of which were widespread and sympatric, while the third was confined to Vanuatu. Another species, C. maculatus is rather similar in appearance, to the extent that questions were being raised as to the validity of the taxon complex.

My task was to look at this group using molecular methods. In particular, I used three genes to investigate the relationships between these four taxa, and any other species of Carpophilus I could get my grubby hands on. I found that C. maculatus is indeed a distinct species from C. oculatus, and also found sufficient evidence to warrant raising the subspecies from Vanuatu to a full species. The other two subspecies, while being somewhat distinct, did not form entirely separate groups, which suggests that something interesting has happened in the genetic history of these taxa. It was a successful and enjoyable project, and I am proud to say that I completed my MSc with first class honours.

So far, so good. However, the currency of modern academia is peer-reviewed publications. The preparation of manuscripts is an arduous process, and over the past two years the one describing the aforementioned research has been languishing on various people's desks (mine, mainly). In the past month though, it been brought into the light of day and has been published in Molecular Phylogenetics and Evolution. Check it out! If you don't have access to it, feel free to email the author.

References:
Brown SDJ, Armstrong KF, Cruickshank RH. 2012. Molecular phylogenetics of a South Pacific sap beetle species complex (Carpophilus spp., Coleoptera: Nitidulidae). Molecular Phylogenetics and Evolution, 64(3), 428–440

Featured insect: Polyrhanis dabraensis (Coleoptera: Cicindelidae)

Tiger beetles (family Cicindelidae) are active predators as adults, pursuing their prey by running and flying. The larvae are bizarre looking things, and catch their prey by sitting and waiting in holes in clay banks and the like (such as one I found in my youth in the Solomon Islands that had taken up residence in a spent WWII rifle cartridge)

Polyrhanis dabraensis is a beautiful tiger beetle from Western New Guinea that was recently described by Andrey Matalin and Fabio Cassola. The insect fauna of this region is fairly poorly known, but the tiger beetles are doing fairly well for themselves. A total of 64 species are known from the region, though undoubtedly more are yet to be discovered. A list of the known species is available on the Website of the Papua Insects Foundation, which also includes images for a select number of species.

Picture courtesy of the Korean Society of Applied Entomology, Taiwan Entomological Society and the Malaysian Plant Protection Society.

References

Matalin AV, Cassola F. 2012. A new species of the genus Polyrhanis Rivalier, 1963 (Coleoptera: Cicindelidae) from Papua (New Guinea, Indonesia). Journal of Asia-Pacific Entomology 15(1): 196-199.

Bohumiljania of New Caledonia

Today in Zootaxa a paper was published describing a number of species in the leaf beetle genus Bohumiljania from New Caledonia. Unfortunately, these species aren't going to win many prizes in the beauty stakes—they're all pretty nondescript, generic looking chrysomelids (See the picture of Bohmiljania aoupinie above). However, it belongs to a group (the Spilopyrinae), that displays a classical Gondwanan distribution pattern so it will be of interest to those people who are interested in the biogeography of New Caledonia. These beetles tend to be found in mountainous areas, and all known hostplants are in the Myrtaceae.

Incidentally, this is Zootaxa's 3000th issue. Pretty good going for a journal that celebrated its 10th birthday on 28 May this year.


Reference:
Reid CAM, Beatson M. 2011. Revision of the New Caledonian endemic genus Bohumiljania Monrós (Coleoptera: Chrysomelidae: Spilopyrinae). Zootaxa 3000: 1-43. The full 6 MB article is here

Koleopterologische Rundschau

The Austrian entomological journal Koleopterologische Rundschau is an excellent serial that is focussed on beetle taxonomy. It publishes a single issue a year, but this issue is filled to the brim with interesting and informative papers on beetles of all families from Europe and the world. Issues prior to 1990 (Volumes 1-59) are freely available online. PDF versions of papers published since then are also available, but at a cost. Unlike some other outfits though, this cost is actually reasonable; being around 1 Euro per paper.

Featured insect: Oxymorostes riedeli (Coleoptera: Hybosoridae)

It's been an interesting month, and what better way to finish it off than with an interesting beetle! I present Oxymorostes riedeli, a bizarre leaf-litter inhabiting beetle from West Papua described in 2009 by Alberto Ballerio. Not only does this beetle look wierd with its out-of-proportion pronotum being wider than its elytra, but it also has several cavities in its mouthparts and underside the function of which is currently unknown. Several other beetles, most notably the bark beetles, have similar cavities known as mycangia in which they store the spores of their food fungus. This is unlikely to be the case in this beetle though, as fungal spores have not been found in them. They did however have an "unknown substance of uncertain origin" inside them, for which there was "an unsuccessful attempt was made to analyze the substance". Just adds to the wierdness really.

Oxymorostes is placed in the subfamily Ceratocanthinae of the Hybosoridae, a worldwide though little known family similar to the scarab beetles. The Ceratocanthinae in general are pretty cool, with some very beautiful species in it such as this currently unknown Eusphaeropeltis species from Malaysia.




References:

Ballerio A. 2009. Unusual morphology in a new genus and species of Ceratocanthinae from New Guinea (Coleoptera: Scarabaeoidea: Hybosoridae). The Coleopterists Bulletin 63(1):44-53

Ballerio A, Maruyama M. 2010. The Ceratocanthinae of Ulu Gombak: high species richness at a single site, with descriptions of three new species and an annotated checklist of the Ceratochanthinae of Western Malaysia and Sinagapore (Coleoptera, Scarabaeoidea, Hybsoridae). Zookeys 34:77-104

Grebennikov VV, Leschen RAB. 2010. External exoskeletal cavities in Coleoptera and their possible mycangial functions. Entomological Science 134:81-98

German Beetles

In addition to having a superb gallery of photos of a huge number of weevils (see one of my previous posts), Christoph Benisch and colleagues have been displaying a featured beetle every week. In addition to having a typical beauful photo of the chosen insect, it is accompanied by a short note on its biology, distribution and lifecycle. Many of the species are endangered and rarely found, while others are strange or unusual in other respects.

A miscellany including the beetles of Gibraltar and Libya

In my continual meanderings through the wonders of the world-wide web, I have uncovered the following gems: A list to the beetles of Gibraltar, and a site on the Beetles and Rock Art of Libya which includes a list of the weevils found in that fair country.

If old entomological art is more your thing, this page showcasing the art of Edmund Reitter is both fascianting and beautiful. If you'd prefer to see a beetle walk, there's an animation of it here.

Featured insect: Ceresium tuberculatum (Coleoptera: Cerambycidae)

One of the unfortunate aspects of South Pacific entomology is the lack of Pacific Islanders that are actually involved in the discovery and naming of their biota. Thankfully, there are signs that this situation is beginning to change. Last August on a trip to Fiji I had the immense privilege of meeting a number of young scientists from Fiji, the Solomon Islands and the Cook Islands. One of these was Hilda Waqa, the senior author of this paper describing two new Fijian longhorn beetles, one of which is the beetle pictured, Ceresium tuberculatum.

The Cerambycidae commonly known as the longhorn beetles tend to be wood borers in the larval stages. These larval stages can last for a long time---several years in some species. The larvae of some of the larger species are eaten occasionally and are considered delicacies in some areas. Unfortunately, very little is known about the biology of Ceresium tuberculatum specifically. It has been collected from the Fijian islands of Gau and Viti Levu, and have been collected from primary, undisturbed forest in the heart of Viti Levu as well as secondary, plantation forests in the vicinity of Suva.

The paper is well illustrated with some very clear photos of various characters that are useful for identification. Unfortunately though, there is little in the way of comparison with other species of Ceresium in Fiji and the South Pacific. This makes the paper less useful than it might have been. It remains a valuable addition to the literature, and it is well worth having a look at for the illustrations alone, whether or not you have any further interest in Cerambycidae.

References:
Waqa H, Lingafelter SW. 2009. New Fijian Callidiopini (Coleoptera: Cerambycidae). In: Fiji Arthropods XV. Edited by Neal L. Evenhuis & Daniel J. Bickel. Bishop Museum Occasional
Papers 106: 3–15 (2009).

South American Weevils

This, the next website on the weevils of the world, is the extremely indepth website of Juan Enrique Barriga-Tuñón on the beetles of South America. As is expected, this is an extremely ambitious project and the fact that it has such a range of photos from several orders and numerous countries speaks of the passion of its creator.

The photos are of varying quality from well-focussed, well-coloured dorsal and lateral images that would no doubt be invaluable for identification (such as the Acrotomopus obtusus pictured here); to dark, poorly-focussed images that are of little value for identification purposes.

Several pages include short species accounts that include specimen labels and reference lists. The species from Argentina in particular frequently have these species pages devoted to them. The site is in Spanish, however there no block of spanish prose and the navigation is straight-forward enought that I (who is not known for my grasp of spanish) was able to get around easily.

Having a cursory scroll through many of the species listson the site, it strikes me that these countries don't seem to have too many genera, but that many of these genera have a huge number of species in them. Naupactus and Listronotus are a couple of the cases in point in the Argentina list above. Whether this is evidence of some hyper-radiations in the evolution of these things, or merely that these particular genera have had more taxonomic work done on them than the others I don't have the familiarity with the region and the fauna to tell.

European weevil photos

Surfing the internet just now I stumbled across the website of Attila Podlussány, a Hungarian amateur entomologist with a particular interest for weevils.

To the left is a photo of the beautiful Stephanocleonus nigrosuturatus. This photo, and a whole lot more, are featured in the extensive photo gallery. That link directs one to the Curculionidae gallery, however most of the other curculionoid families have galleries of their own also.

An excellent resource for people interested in European weevils, and for people who like looking at nice photos of cool animals in general.

Featured insect: Platytenes occultus (Coleoptera: Curculionidae)

Last year, Gregory Setliff (of New Guinea weevil checklist fame) and Peter Larson described Platytenes occultus, a handsome, widespread and common weevil found throughout the Solomon Islands including Bougainville. Until this time, this species has been mistaken for Platytenes varius; until now the only known member of the genus. Platytenes varius is much more widespread, being found from Sulawesi, to New Britain and the Cape York Peninsula. These weevils are part of the subfamily Cryptorhynchinae which are found throughout the world. Most species localised in distribution and so the wide range of both Platytenes species is remarkable.

Both species of Platytenes are frequently found in association with the betel nut palm (Areca catechu) which is grown throughout the Solomon Islands, New Guinea and the Molluccan islands for its fruits which are chewed with pepper leaves and lime powder as a stimulant. This suggests that the wide range of these species may be due to human-mediated movement through the historic trade of betel nuts and palms within the region.

In keeping with typical cryptorhynchine development, the Platytenes species have been reared from wood. As yet, there are no records of specimens being reared from betel palm; rather they've been reared from Ficus and Nauclea species.

This paper is a well-described, thorough description of a very attractive weevil and one which may have some economic impact due to its (as yet improperly determined) association with betel nut palms. Gregory Setliff has already produced an essential checklist for anyone interested in weevils of the region, and this paper further confirms that he's someone to watch with great interest in anticipation of more great work such as this.


References:
Setliff GP, Larson PA. 2009. The Indo-Australian weevil genus Platytenes Pascoe, 1870 (Coleoptera: Curculionidae: Cryptorhynchinae). Insecta Mundi 00-79: 1-14.

Highly diverse weevils in northern New Guinea

New Guinea is an amazing place. It is one of the final frontiers of exploration, particularly in the biological realm with highly diverse rainforest that cover huge areas and a nearly unbelievable range of habitats from hot, humid mangrove swamp forests to 4,000 m high mountains and glaciers. The diversity of the island astounds everyone who works there and the amount remaining to be discovered absolutely boggles the mind.

A case in point was published late last year, when research on Trigonopterus weevils from the Cyclops Mountains was published. This research was headed up by Alexander Riedel and they looked at the congruence between clades revealed by cytochrome c oxidase 1 (COI) DNA sequences and morphological variation. They found 51 morphospecies which were all congruent with COI data. What is incredible though is the genetic distances within this group. Uncorrected distances between species were incredibly high, the lowest being 16.5% and a mean of 20.5%. Within species variation ranged from 0% (not too surprising), to a whopping 8.8%. To put this in context, a 2% genetic distance is usually bandied about as being the point at which you're thinking that you've got two different species.

This diversity is particuarly impressive when one considers that these results are derived from a single transect in a relatively low area in one mountain range. The authors justifiably expect that more extensive sampling will produce many more species.

Not only are they incredibly diverse, these weevils are also tough. Being cryptorhynchine weevils, their rostrum can fold up into a groove in their thorax when they're disturbed. Unlike most other cryptorhynchines though their elytra are fused together and to the thorax, making them able to withstand extremely high pressure and ensuring that they are very difficult to dissect. This is a problem when dissections are necessary to fully characterise and identify these beetles.

It's a very interesting paper on a really cool group of weevils. Check out the supporting information for habitus photos of the morphospecies and get an idea of the morphological variation in the group.


References:

Riedel A, Daawia D, Balke M. 2010. Deep cox1 divergence and hyperdiversity of Trigonopterus weevils in a New Guinea mountain range (Coleoptera, Curculionidae). Zoologica Scripta 39(1): 63--74.

Insects of the Pacific Rim

J. Linsley Gressitt (and here) was an incredibly productive (some might say workaholic) man. I've heard stories of him typing up manuscripts on military aircraft that weren't the quietest or smoothest of rides. He was passionate about the insect fauna of the Asia-Pacific region and published a lot on the taxonomy and biogeography of several groups, and established the Wau Ecology Institute which has been an important centre for much research on the natural history of PNG.

It is fitting then that one of the finest collections of South Pacific insects is named after the man. The J. L. Gressitt Centre for Research in Entomology is housed at the Bishop Museum in Hawaii and houses over 14 million specimens, many of which were collected by the man himself. They've recently got themselves an automontage facility, and have begun putting spectacular photos of South Pacific insects online (such as the PNG brentid weevil above). Check out the Solomon Island staphylinids as well... They say they're going to put up something new each week. I really hope they do, because the photos are pretty cool.

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.

Carpophilus publications

Searching for things on Carpophilus species, I came across a couple of papers by Alexander Kirejtshuk on the things. There's one on the nitidulids of India and one on the African fauna.

I was also very interested to find a short report on nitidulid molecular systematics, as I have been completely unaware of any work that's being going on in that vein other than my own.

On the left is a beautiful picture of Carpophilus oculatus. Isn't it nice!

Japanese Weevil database

As some might have guessed from reading other articles on the blog, I have a rather soft spot for the Curculionoidea. Weevils with their snouts and their amazing variety of shapes and sizes are incredibly cool. Funnily enough though, they remain comparatively neglected by biologists. It's good to see that the excellent Japanese curculiologists Katsura Morimoto and Hiroaki Kojima are adressing this problem with the Japanese Weevil Database. All the navigation is in Japanese, but it's pretty easy to find your way around even if your knowledge of Japanese leaves a lot to be desired. I'm mainly impressed by the scope of the site and the pretty pictures...

Beetle pictures from Southeast Asia

While researching for an upcoming talk, I found the following webpage:

Southeast Asian Beetles

It's pretty cool. It's got very good pictures of over 2000 specimens from 71 different families of weevils. It's also got a very cool and useful interactive locality map which allows you to quickly find specimens from areas of interest. It's based on the Drupal website system, which I personally find rather clunky, but it is free, open source and reasonably easy to develop in.

This site is also another example of the importance of taxonomy, and how much needs to be done in biodiversity-rich regions like Southeast Asia. Comparatively few of the beetles featured have been identified to species level, no doubt due to a combination of there being no relevant specialists and there being a large amount of work to describing new species and revising previous species hypotheses.

Featured Insect: Oryctes rhinoceros Linnaeus, 1758 (Coleoptera: Scarabaeidae)

The coconut palm (Cocos nucifera) is one of the quintessential plants of the South Pacific and its prominence in the lifes and history of the islanders cannot be overestimated. Coconut palms and their products, while not quite as all-encompassing as they used to be, remain a vital food source and cash crop for a large number of people around the world.

Coconuts have many enemies, one of the most serious being Oryctes rhinoceros, a large dynastine scarab beetle. Originating in South Asia, it has spread across the Pacific with the accidental assitance of man. It was first recorded from Upolu, Samoa in 1909, spread to Tonga in 1921, and was discovered on Wallis Island in 1931. World War II was instrumental to the spread of the insect to Papua New Guinea, and Fiji was invaded in 1953. Larvae grow well in a variety of organic matter including decaying vegetation, sawdust and cattle dung. The adult insects causes damage to the leaves, particularly new, actively growing axils. This damage weakens the plants and causes a loss in productivity.

Several methods have been investigated for their utility to control O. rhinoceros. Among these are the use of pathogenic fungi, and and pheromones. One of the most effective however, involves the use of a virus to infect and kill the insects. In 1963, larvae infected with a virus were discovered in Malaysia. Further investigation showed that this virus was effective for control of the beetle, and was able to be cultured in the laboratory. In 1964, the virus was released experimentally in Samoa. The virus spread quicker than expected and caused a major decline in the population of O. rhinoceros. The virus was then introduced to other countries, which also experienced the same decline. Unfortunately, it appears that the virulence of the virus has decreased. Populations are starting to increase, which is sparking further research into the virus and other control methods of the beetle.

C.C. Okaraonye and J.C. Ikewuchi have got an idea for a different biological control agent - humans. The larvae of O. rhinoceros are apparently highly nutritious and full of protein. They don't give any recipes unfortunately, but do say that they can be eaten raw, boiled, smoked or fried...

References:
Bedford, GO. (1976.)
Observations on the biology and ecology of Oryctes rhinoceros and Scapanes australis: pests of coconut palms in Melanesia.
Journal of the Australian Entomological Society 15:241-251

Bedford, GO. (1980.)
Biology, ecology, and control of palm rhinoceros beetles.
Annual Review of Entomology 25:309-339

Huger, AM (2005.)
The Oryctes virus: Its detection, identification, and implementation in biological control of the coconut palm rhinoceros beetle, Oryctes rhinoceros (Coleoptera: Scarabaeidae)
Journal of Invertebrate Pathology 89(1):78-84

Jackson TA, Crawford AM, Glare, TR. (2005.)
Oryctes virus—Time for a new look at a useful biocontrol agent
Journal of Invertebrate Pathology 89(1): 91-94

Okaraonye CC, Ikewuchi JC (2009.)
Nutritional potential of Oryctes rhinoceros larva
Pakistan Journal of Nutrition 8(1): 35-38

Photo courtesy of Huger (2005)