Thursday, 22 July 2010
So when a scale insect that apparently is specific to the plant is found in Italy and Corsica in 2004 and 2006, one would imagine that it came from New Zealand or Australia right?
Acanthococcus mariannae was described yesterday in a Zootaxa paper by Giuseppina Pellizzari and Jean-François Germain. The 30 or so specimens that went into the description were all collected from manuka from Italy and France. Surprisingly though, despite the author's (reasonable) assumption that the insect was introduced to these countries on the plants, this species has not (yet?) been found in either New Zealand or Australia. Moreover, specialists familiar with scale insects in these countries had not noticed it before. While it is likely that further searching will reveal it on manuka in NZ or Australia. However there is the lingering question: if it's not, where did it come from and how has it started attacking manuka?
Scale insects aren't glamorous. They are little more than a bag of fluid that get sap pumped into them. But they are important in a properly functioning ecosystem; and when they get out of control the consequences can be severe. This can be illustrated by an example that also involves manuka: the incidence of manuka blight in New Zealand in the 1940s and 1960s.
Manuka naturally harbours large numbers of the scale insect Coelostomidia wairoensis which produces a lot of honeydew. This in turn provides a food source for the sooty mould Capnodium walteri which covers the branches of manuka forming thick, black deposits.
In the late 1930s manuka in Canterbury (South Island of New Zealand) started to grow sick and die. By the late 1940s it was reported that it was hard to find living manuka in the region. Farmers assisted in the spread by moving infected manuka around the country to control what they viewed as a weed. The culprits were found to be two species of Eriococcus scale insect that presumably had been introduced from Australia. The effect on the plant appears to be due to nutrient stress from having large numbers of scale insects sucking on it as opposed to being a disease transmitted by the insects.
In 1957 it was discovered that a fungus was killing E. orariensis, the species that damaged manuka most severely. Subsequently, the numbers of this scale insect declined dramatically with a corresponding increase in manuka numbers. Manuka has also seen a rise in popularity and is no longer viewed as being as significant a weed.
Monday, 19 July 2010
Friday, 16 July 2010
In a paper by Farah Ishtiaq and coauthors, the birds themselves are not so much of interest. Rather, it's the prevalence of parasites in the blood of the birds found in Vanuatu and New Caledonia. More specifically, they look at the protozoans Plasmodium (more commonly known as avian malaria) and Haemoproteus that are spread from bird to bird by blood-sucking flies and mosquitoes. They took blood samples from a number of specimens, comprehensively sampling five different species of white-eye from Vanuatu (13 islands represented), mainland New Caledonia and the Loyalty Islands. Within these, they found seven different lineages of Haemoproteus and 14 lineages of Plasmodium. Most lineages were fairly scarce, with one lineage of each parasite genus being the most common and widespread.
When they looked at the number of parasite lineages on each island, they found that the larger islands had more lineages of Plasmodium than smaller islands. This trend was much less evident in Haemoproteus, being not statistically significant. The pattern of increasing numbers of lineages or species with increasing island area is a very well-known relationship that forms the basis of the Theory of Island Biogeography, first postulated by Robert MacArthur and EO Wilson in the 1960s. It is interesting that these parasites show the pattern also, despite the additional variables of requiring a host and a vector insect to be present.
Why is this of interest? Parasites have a huge effect on their hosts which is often invisible. They are also a part of the natural heritage of this world and so are worthy of study in their own right. These findings share a small glimpse into a world that is usually hidden, and increases our awareness of the biota of the Melanesian region. As with a lot of scientific research, progress is incremental with many small, initially insignificant findings building into a body of knowledge that can be extremely important for health, conservation, or technological impact.
Ishtiaq F, Clegg SM, Phillimore AB, Black RA, Owens PF, Sheldon BC. 2010. Biogeographical patterns of blood parasite lineage diversity in avian hosts from southern Melanesian islands. Journal of Biogeography 37: 120-132.
Thursday, 15 July 2010
Despite the legendary efforts of Elwood Zimmerman, our knowledge of the weevil fauna of Australia remains rudimentary. Guides to the identification of most species are non-existent and accordingly, very little is known about the life history of a vast proportion of the fauna. What's also interesting is how few people have become involved in the effort to discover more about them. It's not like they're unattractive either. Peter Lang has a number of photos of weevils, particularly the a number of South Australian representatives of the Belidae (including the unidentified specimen here).
There are also a number of photos of the weevils from Brisbane on this site. Take the identifications with a grain of salt though. The "attelabid" is a broad-nosed weevil of some sort, and the latter two species on the Apionidae page appear to be a cryptorhynchine and an attelabid respectively.
Terracircle is an NGO that works primarily in Melanesia promoting sustainable agriculture through technical training, publications, consultancy and the provision of small grants for communities.
Working in close association with Terracircle is the Kastom Gaden Association (another website is under construction here) and the Planting Material Network, both based in the Solomon Islands. Both these organisations operate much more on the grass-roots level, connecting farmers within the Solomons to each other and encouraging communication at that level.
The Melanesian Farmer First Network is broader in scope than the two above, supporting farmers throughout PNG, the Solomons and Vanuatu. I liked the Innovations page on their site, though unfortunately it is only very infrequently updated.
OISAT (or the "Online Information Service for Non-Chemical Pest Management in the Tropics" in full) aims to detail control methods for tropical crops and pests. It seems to have more of a focus on Asia, but the information that is here will be of worth in most places with these crops and pests. It is currently fairly incomplete, with few of the insects in the Pest Management strategy having any information beyond a picture. However, there was a note saying the page had been updated in some form a day ago, so there is hope that this will change in the future.
Monday, 12 July 2010
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.
Sunday, 11 July 2010
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.
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).
Friday, 9 July 2010
It's up there though, and this is why. I blog for myself, and am slowly making this site a place that has links to everything that I need. One thing that I need an easy way to read a random bible verse and meditate on it briefly throughout the day. This sort of thing is rooted in a practice followed by Benedictine monks called "statio"; a standing still. I first came across it while reading "Reaching for the Invisible God" by Philip Yancey, but there's an outline of the practise in this article by a doctor. I'm hoping that having this bible verse up here will get me thinking more on Christ and His love and keep my perspective on things that matter.
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.
Wednesday, 7 July 2010
If you want to get still more music and learn about yet more bands, a useful site to keep checking is the Hype Machine, an aggregator of music blogs. Updating frequently, it's a treasure trove of all things musical. If you want to sign up, it promises that you're able to customize what you see, presumably allowing you to keep tabs on the genres that you particularly enjoy. Otherwise, check it frequently to see what people are listening to and what they think of it...