Cook Islands Insect Expedition: Funding Granted!

Satellite image of Rarotonga, Cook Islands. Image via Wikimedia Commons. Licence: Public Domain.

As the tagline of this blog suggests, I have a profound interest in the biota and people of the South Pacific. I was fortunate to spend an influential part of my childhood in the Solomon Islands, then managed to work on beetles across the South Pacific for my MSc research. Since I've moved on to studying weevils, I've been very keen to contribute to a greater knowledge of the weevil fauna of the Pacific; but until now I haven't had the financial support, nor a topic that is simultaneously ambitious enough to be useful but also achievable.

The Cook Islands caught my eye about a year or so ago, when I realised that the weevil fauna of the group was essentially unknown. What little was published usually didn't get beyond a mention of "Rarotonga" or "Cook Islands" in the Distribution section of a species account in papers that had a different geographic focus. The superb Cook Islands Biodiversity Database lists 35 species of weevil from the Islands, which included several undescribed species and unidentified taxa. Further investigation of the literature revealed that it wasn't just the weevils that were barely known from the Cooks—few collecting expeditions have been undertaken, and not many insect taxa have published data available.

Holotype of Ptilopodius aitutakii Beaver and Maddison. One of two weevils described from the Cook Islands. Image courtesy of Auckland Museum. Licence: CC: BY.

This lack of knowledge surprised me, given the Cook Islands' strategic location in the South Pacific. Being approximately halfway between Samoa and Tahiti, it's in a key position to test hypotheses of the cause of the eastward attenuation of species richness and diversity that is such a feature of the biogeography of the South Pacific. Much has also been made of the fact that several taxa find their eastward limit around Samoa and Tonga, without having data from Niue or the Cook Islands to ascertain if this eastward limit is truly the case or not. A comprehensive work on the weevils of the Cook Islands would be able to confirm or refute some of these ideas of distribution of species in the South Pacific.

The small size of the islands made them attractive too. Rarotonga, the largest and highest of the group, is still only 62 km² in area and 650 m at its highest point. Not too much time (in theory at least!) would be required to make comprehensive collection in the available habitats.

The combination of the geographic location of the Cook Islands, and their small size lets me predict that weevil fauna will be fairly small and depauparate. I'm expecting that the total number of species will be around 200 or so. This is also beneficial, as it gives me hope that I may be able to write up the results of any collecting done in a timely and efficient manner. Additionally, although I expect a lot of the species to be endemic to the Cooks, the genera they represent are likely to be widely distributed, which would result in this work giving me a good foundation for further, future work on the weevils of other Pacific archipelagos

So there were the Cook Islands: small enough to collect everywhere in the space of a few weeks, an unknown fauna with a low number of species that could be written up in a short period of time and opportunity for first-hand experience with Pacific weevil taxa. In my opinion at least, this potential project held a lot of promise.

I am honoured that the board of the New Zealand Winston Churchill Memorial Trust considered it to have a lot of merit also. The trust funds overseas travel that bring New Zealanders into contact with other cultures, learn from their experiences and contribute to the community through their research and knowledge. Over 850 fellowships have been granted since the establishment of the Trust in 1965 and includes artists, educators, economists, academics and musicians. It's an impressive list of highly talented people and it's very humbling to be included among them.

The Trust has offered funding to cover two months in the Cook Islands, collecting weevils and other insects on Rarotonga, Atiu, Mangaia and Mitiaro. I expect it to be a great adventure, and one that I hope will prove productive and useful. I plan to go in March 2017, and intend to post semi-regular updates on aspects of the preparation for the trip, the expedition as it happens, and the aftermath of specimen sorting, preparation and identification. I very grateful that the Winston Churchill Memorial Trust has provided support for this expedition, and I'm excited about being able to make a significant contribution to our knowledge of the insects of the Cook Islands.

Japanese Journal of Systematic Entomology

I've just recently stumbled across the website for the Japanese Journal of Systematic Entomology, the new name for what was previously known as the Transactions of the Shikoku Entomological Society. I've encountered references to this journal before, but they've only recently made a home for themselves on the internet. They promise that older issues will become freely available, but it's a little early in the piece just yet. Here's hoping they're not too far away, because the contents look rather exciting!

Rapid dispersal of Tahitian biological control agents

The glassy-winged sharpshooter (above) and its parasitoid (below). Pictures courtesy of the Center for Invasive Species Research. License: CC: BY-NC-ND

In 1999, Tahiti was invaded by the glassy-winged sharpshooter (Homalodisca vitripennis, a sap-sucking bug that feeds on a huge variety of plants. In the absence of its natural predators, the bug became extremely numerous. This was of concern for two reasons. The first was that the sharpshooter had the potential to spread bacteria that kill plants. The second was more aesthetic. The sharpshooter feeds on the xlyem fluid of plants, which is high in water and low in nutrients. The result is that the insect needs to drink a lot to get the nutrition it needs. In doing so, it excretes the excess water. When sharpshooter numbers get high, the result can be fairly unpleasant as this video shows. The "rain" in the video is actually water secreted by hundreds of glassy-winged sharpshooters.

Something had to be done, and it was. After pre-release testing, a minute parasitic wasp Gonatocerus ashmeadi (pictured above) was released on the island in 2005. This wasp parasitises the eggs of the sharpshooter. It rapidly became established, and glassy-winged sharpshooter numbers plunged dramatically. When I visited Tahiti in 2008, I found very few sharpshooters despite extensive collecting on the island.

A paper by Petit and co-authors investigated the dispersal of the wasp from two release sites on the island. Sites up to 5 km away were regularly monitored after the wasps were released, to determine how quickly they were moving around. They found that the wasps only took 50 days to be collected 1 km away, and were first collected from the 5 km sites 106 days after the initial release. The team calculated that this insects that is less than 2 mm in length was travelling at around 40 m/day.

This biological control scheme has been especially effective, and will (or should) become a textbook example of successful biological control introductions. Results have been clearly recognised within a short time period, thanks to this parasitoid which has managed to disperse rapidly despite its size.

Reference:
Petit JN, Hoddle MS, Grandgirard J, Roderick GK, Davies N. 2008. Short-distance dispersal behaviour and establishment of the parasitoid Gonatocerus ashmeadi (Hymenoptera: Mymaridae) in Tahiti: Implications for its use as a biological control agent against Homalodisca vitripennis (Hemiptera: Cicadellidae). Biological Control 45: 344-352

Dispersal of crickets to New Caledonia

An eneopterine cricket in the genus Cardiodactylus. Photo courtesy of Guido Bohne

New Caledonia is one of the largest islands in the Pacific, being exceeded only by New Guinea, New Britain, and the main islands of New Zealand. Like New Zealand, the composition of the biota, which includes several relict groups such as the Amborella shrub and the Kagu (Rhynochetus jubatus), has lead many to believe that the island is a fragment of Gondwana, with a long biological history. Also like New Zealand, this story has been questioned in recent years by geological evidence that the island underwent submergence at various points in its history, and that the biota is a result of long-distance dispersal. Cue a classic dispersal-vicariance stoush that is a trademark of biogeographic discussion.

In the dispersal corner is Romain Nattier and coauthors, who present evidence of a "recent" arrival in New Caledonia of the eneopterine crickets. This subfamily of crickets have a wide range throughout several islands of the Pacific, South-East Asia and South America. Their analysis of four genes show that the New Caledonian eneopterine crickets are most closely related to species on other Melanesian islands, and that they've likely been in New Caledonia for "only" 5–16 million years. They then use this evidence to indicate argue against an ancient presence of New Caledonia.

I've got no quarrel with their conclusions regarding this group of crickets. The evidence for a recent arrival of these guys seems pretty clear. However, I do wonder why the authors chose this group of insects to test their hypothesis. The distribution of the non-New Caledonian species suggests that this group is fairly vagile. Their presence in archipelagoes such as Vanuatu, a young island group by most people's standards, hints at their dispersal ability. Much more convincing with regard to their New Caledonia drowning hypothesis would be one of the groups that is less likely to move around as much. Of course, with this criteria, the taxon of choice would be likely to be one of the relict species—which by definition are species poor and with few close relatives—leading to a biased outcome.

I was surprised that none of the Australian representatives were closely related to the New Caledonian crickets. An Australia–New Caledonia link is a fairly common pattern in New Caledonian biogeography, but it hasn't held up in this instance. I was also surprised by the sister-taxon relationship between a genus in Fiji and Samoa, and a couple of genera in Central and South America. Those sorts of relationships seem fairly strange, but not too much stock can be placed on it without knowing more details about the group, and the sampling regime used in the study.

As always, this is not the last word on the subject of the origin of New Caledonia and its biota. It isn't even the definitive on the evolution of this group of crickets. This is one piece of the puzzle that is New Caledonia's biota, and one that will illuminate further research on the natural history of the island, as well as being a valuable addition to the literature of eneopterine crickets.


References:
Nattier R, Robillard T, Desutter-Grandcolas L, Couloux A, Grandcolas P. 2011. Older than New Caledonia emergence? A molecular phylogenetic study of the eneopterine crickets (Orthoptera: Grylloidea). Journal of Biogeography 38: 2195–2209

Vanuatu Caddisflies

A recently published paper by Kjell Johanson revises the caddisfly fauna of Vanuatu, descibing 12 new species and providing a key to the species currently known from the archipelago. It is an important contribution to the knowledge of the caddisfly fauna of the region, as most of the previous work done on the fauna of the region is several decades old.

A couple of things stood out to me in this paper. The first is that Orthotricha has not been recorded from any other oceanic Pacific islands. These are small (2-3 mm wing length) creatures, and it is likely that they just haven't been collected elsewhere in the Pacific. The second was their discovery that a female of Triplectides australis had a large number of larvae inside her abdomen. While I was hitherto unaware that ovoviviparity occurred in caddisflies, it turns out that this has been known since 1890, the first instance of it being confirmed by Prof. Wood-Mason in the following manner:

I threw the insect alive into a liqueur-glass of whiskey that happened to be ready at hand.

Adult caddisflies tend to be overlooked by the general public, usually being confused as small, fairly dull-looking moths. Their larvae are aquatic where they form an important part of the macro-invertebrate fauna of streams, and can be useful as indicators of water quality and stream health. Unfortunately, very little biological information is recorded in the paper, and larvae are not considered. In part this is due to Malaise and light traps providing the bulk of the material that was considered in the revision. Discovering and describing larvae and their habitats is a natural application of the taxonomic effort of this paper.

References

Johanson KA, Wells A, Malm T, Espeland M. 2011. The Trichoptera of Vanuatu. Deutsche Entomologische Zeitschrift 58(2): 279-320.

Wood-Mason J. 1890. On a viviparous caddis fly. Annals and Magazine of Natural History 6th series, 6: 139-141.

Jetsetting Dragonflies

Image: Muhammad Mahdi Karim

Not only not are dragonflies some of the best aeronauts of the insect world, some also have the greatest endurance. A couple of years ago, it was discovered that the globe skimmer dragonfly (Pantala flavescens) migrates from India to South East Africa via the Indian Ocean islands of the Maldives and the Seychelles, and back via East Africa. That's a grand total of around 18 000 km. That's a fair bit further than the 11 000 km I recently traveled from New Zealand to South Africa. It is considered that the round trip takes place over several generations, but it's still an amazing phenomenon.

For more information, there's news reports from Wildlife Extra and the Daily Mail; and a blog post from National Geographic. There's even a graphic on DeviantArt celebrating the journey. To hear it from the horse's mouth (so to speak) watch a video of Charles Anderson himself talking about his findings.

Harvard's Caribbean Insects

Harvard University has has an interest and presence in the Caribbean for the past 150 years. As you can imagine, they've accumulated a lot of information on the biota of the region. They've made a sizable portion of their entomological knowledge available on the Caribbean Insects @ Harvard Entomology webpage, which is very nice of them. of particular interest are is the insect and plant database which you can search to find specimen information, or cool photos, like the image of Eurhinus festivus suturalis above. They've also made a whole lot of papers available through their taxonomic literature database, though unfortunately I was unable to access the database for some reason or another. Finally, they've made a number of posters of different taxa available, and very kindly sent me copies of their beautiful weevil and bark beetle ones. Good on them for creating all this cool stuff!

Mounting insect specimens in resin

I do a number of school presentations throughout the year, and am frequently asked if I can bring a few specimens to show the students. I am usually fairly loathe to do so, because of the fragility of most specimens, and the fact that the majority of my specimens are fairly small and therefore not especially exciting. Getting into work today, I saw a couple of resin-encased beetles I have received as gifts and had a brainwave. A quick search for instructions for how to do it revealed a number of tutorials. The one by Dalchem is useful, as is the guide provided by Complete Paints.

Amphibious caterpillars in Hawaii

The Hawaiian Islands are renowned for their unique biota that display a number of bizarre adaptations that do not appear elsewhere in the world. Widely known examples of these include the predacious caterpillars in the genus Eupithecia, and the wekiu bug (Nysius wekiuicola) that lives on Mauna Kea eating insects that are blown to them on the wind.

Recent work by Daniel Rubinoff and Patrick Schmitz have added another example to the list: amphibious caterpillars. In a paper published in March in PNAS they describe the ecology of some recently discovered 12 currently undescribed species of the moth genus Hyposmocoma that are able to develop equally well both in and out of water. Intriguingly, a phylogenetic tree hypothesizing the evolution of these insects suggest that this amphibious trait arose independently at least four times, an unexpected result for a specialised trait such as amphibiousness.

The major driving force for the development of this unique lifestyle in Hawaii is believed to be due primarily to a lack of competition. Hawaii lacks the major aquatic insect orders of the stoneflies, mayflies and caddisflies (the latter two represented by introduced species only), leaving Hawaii's freshwater environments unexploited. Hyposmocoma has stepped into the breech.

In addition to the written paper, the authors have provided movies showing the caterpillars moving in and out of the water. They are provided as supplementary information to the paper and available on the PNAS website here and here. Unfortunately, a David Attenborough documentary this isn't. There is no informative commentary spoken with a British accent, but it is an interesting watch nonetheless.

References:
Rubinoff D, Schmitz P. 2010. Multiple aquatic invasions by an endemic, terrestrial Hawaiian moth radiation. Proceedings of the National Academy of Sciences of the United States of America 107(13):5903-5906

Zimmerman EC. 1957. Insects of Hawaii. Volume 6, Ephemeroptera-Neuroptera-Trichoptera and Supplement to Volumes 1 to 5. University of Hawai'i Press.

Origami

Origami is pretty amazing. While my skills have never progressed beyond the traditional crane, I am always amazed at how people can make a square of paper into something amazing. This website shows a particularly spectacular gallery including the origami cicada pictured above. What's really cool is that it also includes a diagram of the folding patterns for each model. All that's needed is the interpretation of said diagrams, and the time to do it!

Insect farming

Insect specimens can be big business. There are enough people out there with money to spare, and who find large and colourful insects such as butterflies, jewel beetles and certain scarab and longhorn beetles worth spending it on. As in all things, this offers both an opportunity and a challenge. Typically, countries with an abundance of desirable specimens are in the tropics and are classed as developing countries. The insect trade offers a high-value export product that can be sustainably produced and can give value to undisturbed habitats. The converse is the usual danger of unsustainable production and unscrupulous middlemen

The sites that follow are a selection of insect trading websites that I've found that are well illustrated, and have some sort of connection with the Pacific. I am not involved with any of these companies, and cannot vouch for the ethics of their trading practises.

Papua New Guinea company, The Insect Farming and Trading Agency, functions as a link between rural insect collectors and breeders and the trade, and sells a range of butterflies and beetles.

The Insect-Sale site is a Taiwan based outfit that exports insects collected from throughout the world, and particularly South East Asia. It boasts that it has the world's largest number of online insect photographs, and is also notable for its gallery of freak insect specimens.

Finally, InsectNet serves as a portal for a number of other sites that offer insect specimens for sale.

Solomon Island Caddisflies

Caddisflies (order Trichoptera) are one of the major groups of aquatic insects, well known for building cute cases out of sand, grit and other detritus.

While having a fair number of species, relatively little is known about the group in the Pacific, with the exception of some excellent work being done on the New Caledonian fauna. That being the case, it was excellent to see that nine species were described in a paper recently published in Zootaxa, authored by Kjell Arne Johansen, the man behind the current work on New Caledonian Trichoptera. With only 16 species previously described from the islands, this represents a fairly sizable addition to our knowledge of the caddisflies of the Solomon Islands.

References:

Johansen KA, Espeland M. 2010. Description of new Chimarra (Trichoptera: Philopotamidae) species from the Solomon Islands. Zootaxa 2638:25-43

Houseflies of New Caledonia and Vanuatu

Over the past couple of months, Marcia Couri and colleagues have published two monographs on the Muscidae of New Caledonia and Vanuatu. These two papers describe six new species with nine other species recorded from the region for the first time. The world-wide house fly Musca domestica (pictured here) is newly recorded from a number of islands throughout Vanuatu.

These papers are important additions to our knowledge of Melanesian flies. They give keys and diagnoses for the genera and species found in each archipelago, and give comments on the wider distribution of the flies found. Unfortunately, there are few illustrations, limited to line drawings of taxonomically important structures of the newly described species. While this may limit their utility to users who don't already have some familiarity with the group, these paper effectively summarize the housefly fauna of the region and provide a good basis for the further study of this important group.


References:
Couri MS, Pont AC, Daugeron C. 2010. The Muscidae (Diptera) of Vanuatu. Zootaxa 2556: 1–39
Couri MS, Pont AC, Daugeron C. 2010. The Muscidae (Diptera) of New Caledonia. Zootaxa 2503: 1–61

New hemipteran species from New Caledonia

In the same issue of Zootaxa describing the manuka scale insect, another hemipteran was described. Teabooma secunda is the second species of the genus (which is endemic to New Caledonia) to be described. It is in the family Cydnidae which are common and widespread. They are frequently mistaken for beetles, and it is usually only a careful look with some magnification that will reveal the mistake. It's a poorly known family, but they are thought to feed on roots, seeds and fallen branches. None are known for their economic importance.

References:

Lis JA, Lis B. 2010. Teabooma secunda (Hemiptera: Heteroptera: Cydnidae)---a new species of a New Caledonian endemic genus with a redescription of T. princeps Distant. Zootaxa 2543: 64-68.

PNG Entomology Textbook

Michael Schneider was a lecturer at the Bulolo University College in Morobe Provence, PNG from 1994 to 1999. As a result, he has produced both a key to the Insect Pects of PNG, and an entomology textbook for students and forestry. This last work is a particularly impressive effort, being a clear, informative and thorough textbook with a strong emphasis on the insect fauna of Papua New Guinea. For anyone with a developing interest in insects, it's well worth checking out. For those of us who are particularly fascinated with the insects of Melanesia though, it's a must-see.

Fauna Hawaiiensis

I've always been surprised how hard it's been to find information on the beetles of Hawaii. Due to it being a state of the USA and the fascination for many other aspects of the fauna and flora of the islands I would've thought that it would be very easy to find out pretty much anything about the beetles of the area. This expectation for the most part has not been met.

Lately though, I've been having more luck. The other day I found the Proceedings of the Hawaiian Entomological Society, and today I found the website of Karl Magnacca. He's working on the Drosophila of Hawaii which form a very famous radiation with approximately 600 species found in Hawaii. A big task. He's also taken a number of photos of Hawaiian beetles, and has put online the masterpiece of early Hawaiian biological study: Fauna Hawaiiensis. This ambitious project details the entirety of the animals from Hawaii at that time. Vertebrates, insects, worms, springtails, molluscs: it's all here.

South Pacific insects in a Russian Journal

The Russian Entomological Journal is not the usual outlet for taxonomic research on South Pacific insects. That said, it has published a number of papers over the last few years that are freely available to everyone on their website. For some reason, they all deal with the Hemiptera. So, if you ever wanted to know about Microveliines from Fiji, Maana emeljanovi (Lophopidae) from West Papua, or Nerthra kerzhneri (the first species of the Gelastocoridae found from New Caledonia, pictured), now you know where to look.

European Weevil photos Part II

In addition to the website mentioned in my previous post about European weevils, there is a stunning site with a whole bunch of habitus photos of German weevils, including the picture of Chlorophanus viridis shown to the left. There are a whole range of genera pictured and it of great value to people wanting to identify or become familiar with the weevils of the country.

Featured insect: Aureopterix micans (Lepidoptera: Micropterigidae)

The moth fauna of the Pacific is still fairly unknown, with most of the work that's been done on the region's being rather old and with few recent revisions. An addition to the literature was recently published by George Gibbs in Zootaxa today on the Micropterigidae of Australia, New Zealand and New Caledonia. In it, he describes the species pictured:

Aureopterix micans from New Caledonia. This beautiful species is fairly widespread and common throughout New Caledonia at moderate altitudes.

As suggested by the name of the family, the Micropterigidae are part of the microlepidoptera---an informal name for a bunch of families that are small and tend to escape the notice of the public. They also tend to escape the notice of most specialists, and so their biology is not particularly well known. This is true for Aureopterix micans, however, the larvae for some of the other species described in the paper are known to feed on foliose liverworts. This is likely to be true of A. micans also.

It is believed that the distribution of the Micropterigidae may offer insights into the biogeography of the South Pacific region. The distribution of Auropterix offers a fairly standard interpretation of New Caledonian biogeography. While A. micans is restricted to New Caledonia; the only other species currently known in the genus, A. sterops, is found in northern Queensland, Australia. This East Coast Australia---New Caledonia connection is fairly typical of a lot of the fauna of the island. Other species of Micropterigidae however do not show this pattern, being closer to species in New Zealand than Australia. While Biogeography is full of interesting details such as these, going from hypotheses of pattern to process can be difficult to test, and will require greater research into the fauna of each area and underlying geology and ecology of the species involved.

References:

Gibbs GW. 2010. Micropterigidae (Lepidoptera) of the Southwestern Pacific: a revision with the establishment of five new genera from Australia, New Caledonia and New Zealand. Zootaxa 2520: 1-48.

Featured insect: Doddifoenus wallacei (Hymenoptera: Pteromalidae)

Looking through Zootaxa this morning I came across this and couldn't resist putting it up here...

This is a parasitic wasp named Doddifoenus wallacei. It is in the family Pteromalidae, which is part of the superfamily Chalcidoidea. The wasps in this superfamily are ubiquitous, but not many people notice them as they tend to be very small---most of the ones that I've come across don't get much bigger than 2 mm. When you do notice them and get them under a microscope though, they are some of the most beautiful things you'll see. Metallic golds, shimmering wings and usually some pretty cool looking morphological structures. With D. wallacei though, you don't necessarily need a microscope to appreciate it. Not including its ovipositor ("sting"), it measures between 17 and 19 mm. When the ovipositor is included, the thing measures a whopping 34--41 mm. That's massive for a chalcidoid and rightly deserves the "giant parasitoid wasp" in the title. If you're worried about a wasp having a sting that long, please don't. It is believed to parasitise wood-boring insects, and it's long ovipositor is used to bore through wood to get to the victim.

While this species is found in South-East Asia, and so not a South Pacific species, the two other species in the genus Doddifoenus are found in New Guinea and tropical Queensland, Australia. This makes Doddifoenus one of the creatures that crosses Wallace's Line, the famed division which separates the Asian biota from the Australian. Like all of humanity's categorisation of the natural world, it breaks down in several details, however as an overall trend it remains useful.

References:

Krogmann L, Burks RA. (2009). Doddifoenus wallacei, a new giant parasitoid of the subfamily Leptofoeninae (Chalcidoidea: Ptermoalidae), with a description of its mesosomal skeletal anatomy and a molecular characterization. Zootaxa 2194: 21-36.