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.

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

Featured insect: Pantorhytes plutus (Coleoptera: Curculionidae)

The weevil genus Pantorhytes is a large genus placed in the tribe Pachyrhynchini in the subfamily Entiminae. It consists of over 74 species found primarily in New Guinea, but also being found in the Solomon Islands and Queensland. The species pictured here, P. plutus is found in the Bismarck Archipelago. A map showing the distribution of specimens in the Australian National Insect Collection (see here also) can be found here

Pantorhytes plutus and a number of other species in the genus have become major pests of cacao trees, particularly in PNG. All the species have fairly limited ranges, such that P. szentivanyi, P. albopunctulatus and P. healyi are pests in the Northern Province of PNG, P. torricellianus is a problem in the Sepik region, P. plutus through the Bismarcks, and P. biplagiatus through Bougainville and the Solomon Islands. The genus has had a surprisingly large amount of study done on their biology, including egg development, and control. A couple of studies have looked at their dispersal, including one study that used a radioactive isotope tracing technique, which provided theoretical insight into mathematical models of insect dispersal. A parasitic wasp, Pristocera rufa is known to parasitize P. szentivanyi, though not to such an extent as to be a reliable biological control agent.


They are such a threat, they have made it onto a page detailing the world's worst cocoa problems (though I cannot find any other evidence that Pantorhytes are in Tuvalu), and accordingly there's been a number of studies dealing to their control (such as this one and this one).Biopesticides, including Beauveria bassiana have also proved to be of use in their control. A photo of an infected beetle is shown above.

A circular detailing their control in the Solomon Islands recommends using ants as a form of biological control. Unfortunately, two of the species they recommend for this control are the yellow crazy ant (Anopolepis gracilipes) and the little fire ant (Wasmannia auropunctata). Both these species are highly invasive generalist predators and scavengers which have adverse effects on more than just Pantorhytes weevils in cacao plantations. Should they already be present in the area, their use as a control agent may be encouraged, but they should NOT be introduced anywhere for that purpose if they aren't already there.

References:
Gressitt JL. 1966. The weevil genus Pantorhytes (Coleoptera) involving cacao pests and epizoic symbiosis with cryptogamic plants and microfauna. Pacific Insects 8(4):915-965.
Setliff GP. 2007. Annotated checklist of weevils from the Papuan region (Coleoptera: Curculionoidea). Zootaxa 1536. 296pp.
Stibick JNL. 1978. The genus Pantorhytes (Coleoptera: Curculionidae) Division A. I Addistions and changes to the common and major cacao species. Pacific Insects 18(3&4):115-136.

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).

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.

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.

Featured insect: Immetalia aurea (Lepidoptera: Noctuidae)

While searching for some information on Pacific moths for a colleague, I found the following species: Argyrolepidia megisto. Isn't it pretty! It is a member of the subfamily Agaristinae in the large and cosmopolitan family Noctuidae which includes such infamous creatures as Helicoverpa armigera, the species within Heliothis and the various cutworms. Unfortunately these bad few taint the rest of the family which mind their own business and don't feed on plants that we find useful. The Agaristinae are primarily found in tropical regions and tend to be bright and gaudy creatures. These galleries of the North American, Australian and Borneo species give particularly good displays of how beautiful these things can get. It's not only the adults that look good... the caterpillars also look spectacular.

The site that hosts this photo, The Papua Insects Foundation is an excellent site that appears to be well-maintained and updated and is thus a very, very valuable resource for entomology in general and for Pacific entomology in particular. It is especially good when it is taken into account that West Papua is the lesser-known half of the most diverse island in the world (though Borneo and Madagascar might give it a bit of a run for the title...).

Another good resource for this part of the world is "The families of Malesian moths and butterflies", a preview of which is available for all on Google books. Unfortunately it is not complete, but thankfully a number of the colour plate are reproduced.

Finally, for those of a taxonomic bent, the Natural History Museum hosts a database of butterfly and moth generic names which gives information on type species, authority, availability and a reference to the description. Pretty handy if you're looking for that info, but rather dry if you're not...

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.

Featured insect: Tossinola pamianorum (Hymenoptera: Ichneumonidae)

When the word 'wasp' is mentioned, people get scared as the image of angry yellow jackets or paper wasps is conjured up. When I tell people that I'm interested in them, they tend to respond with a sense of bewilderment and treat me as if I'm crazy.

The order Hymenoptera is one of the largest insect orders, being beaten only by the beetles. Of that, only a small proportion sting, bite or otherwise make a nuisance of themselves, the others minding their own business and performing their vital services to the environment. A good many of them are parasitoids of other insects, their young developing in eggs, larvae, pupae or adults of other species. Frequently, species are host-specific in that one species of parasitic wasp will only develop in a single species of insect.

The featured insect for today, Tossinola pamianorum was recently described from Colo-i-suva in Fiji by Andrew Bennett as a result of the Fijian Terrestrial Arthropod Survey. It is in the subfamily Banchinae of the family Ichneumonidae, which is not only one of the major wasp families, but is one of the largest families of insects in general. A rare species, it was described from seven species from the total haul of the survey. While the host is not yet known, other species in the same group lay their eggs in caterpillars. One particularly gruesome feature in this instance, is that the caterpillars continue to move, eat and grow despite being inhabited by a parasitic wasp...

What is particularly interesting about this species of wasp is that it is the first time this subfamily has been found in Fiji. The genus is also known from the Philippines, Central Asia and West Africa, so there's some huge gaps in the distribution of this species. The subfamily has no other representatives in the South Pacific, though there are a number in Australia and New Zealand, so it may well be that people haven't looked for them rather than that there are none there.

This is not surprising, as the Ichneumonidae has been very poorly worked on despite (or perhaps because of?) it's size and economic importance. A great thing about this paper is that it not only starts to reveal some of the ichnemonid diversity of the South Pacific, but it also provides a useful entry into the fascinating world of Ichneumonidae taxonomy in general. A very interesting and worthwhile publication.

References:
Bennett AMR. 2009. The Ichneumonidae (Hymenoptera) of Fiji: keys to subfamilies and genera with a review of the species of Anomaloninae, Banchinae, Brachycyrtinbae and Diplazontinae. In: Evenhuis, N.L. & Bickel, D.J. (eds.), Fiji Arthropods XIV. Bishop Museum Occasional Papers 105: 3-68.

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)

Featured insect: Gymnopholus weiskei Heller 1901 (Coleoptera: Curculionidae)

Today is the first of what I hope will become a relatively regular thing - a feature on various South Pacific insects. The lucky candidate, by virtue of being able to source a cool picture, and having found a paper on the genus Gynmopholus....

Gymnopholus weiskei is a large beetle, around 3cm long. It is found in the Morobe province of Papua New Guinea, and feeds on a range of host plants including yams (Dioscorea spp.), brambles (Rubus archboldianus) and chinaberry (Melia azedarach)

Gymnopholus weiskei was first described by Dr K. M. Heller in 1901 and is the type species for the genus. This means that for a weevil to be named in the genus Gymnopholus, it must have several key similarities with G. weiskei.

There is another very cool photo of G. weiskei here.

References:

Marshall, GAK. (1959). Curculionid genus Gymnopholus (Coleoptera).

Occasional papers of the Bernice P Bishop Museum. 22(7):71-81

Szent-Ivany, JJH. (1970).
Ethological and ecological observations on Gymnopholus spp. mainly G. (S.) lichenifer Gress. (March-April 1967).

Pacific Insects 12(4): 763-768

Photo courtesy of bugsbynature.com