Monthly Archives: February 2013

Earthling Bulletin #14

by Piter Kehoma Boll

You have sex, loose your penis and it grows back the day after. That happens with this sea slug. Photo by Matthew Oldfield, extracted from nature.com

You have sex, lose your penis and it grows back the day after. That happens with this sea slug. Photo by Matthew Oldfield, extracted from nature.com

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Friday Fellow: Violaceous Longhorned Beetle

by Piter Kehoma Boll

ResearchBlogging.org Beetles are the most species-rich group of living beings on our planet, so it’s time for Friday Fellow bring you a representative of them. I’ve chosen my favorite species, the violaceous longhorned borer Compsocerus violaceus (White, 1853).

Isn't it a beautiful creature? Photo by Silvio Tanaka*. Extracted from flickr.com/photos/tanaka/87228732/

Isn’t it a beautiful creature? Photo by Silvio Tanaka*. Extracted from flickr.com/photos/tanaka/87228732/

With a beautiful pair of metallic blue elythra and an orange body with long antennae bearing a black tuft, this species is very charismatic and appears during spring and summer here in southern Brazil, being usually seen on trees, especially from November to January. When grabbed or let inside a closed hand, it uses to emit a sound like consecutive short squeaks, which may be the reason why it is also called “besouro guitarrista” (guitarist beetle).

Despite its cuteness, however, it is considered an agricultural pest, attacking trees from different species, including acacias, eucalypts, willows, fig trees, citrus trees and peach trees.

Adults feed on fruits and sap leaking from injured trunks, while larvae feed on the wood itself, constructing galleries in it.

When ready to make the posture, females walk over branches searching for cracks in the bark to lay the eggs, sometimes making small transversal cuts for the same purpose. They use to lay eggs on the same tree where they emerged. Eggs are laid isolated, but many of them can be left on the same branch. Each female lays about 60 to 130 eggs.

As the larvae grow and increase their gallery inside the wood, the branch shows significant changes in aspect, with the bark becoming darker and leaves yellower.

In cases where too many larvae are present in a branch, it usually dies and may even break off the tree due to the damage caused.

Who has the responsability for turning this lovely species into a pest? We, humans, of course. Since we plant hundreds of trees together in large orchards, we are kind of advertising “tons of food here”. And when they come, we blame it on them.


References:

Garcia, H. A. 1994. Ocorrência e danos de Compsocerus violaceus (White, 1853) (Coleoptera, Cerambycidae) em pomar de citros. Anais das Escolas de Agronomia e Veterinária, 24 (1), 148-153

Garcia, A. H., & Cunha, M. G. 1994. Comportamento da população de Compsocerus violaceus (White, 1853) (Coleoptera, Cerambycidae) em relação a fauna de cerambicídeos coletados em pomares de citros. Anais das Escolas de Agronomia e Veterinária, 24 (1), 154-163

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A tree is more than just a tree

by Piter Kehoma Boll

ResearchBlogging.org Most ordinary people think of a tree as just that, a tree, a big plant with a hard tall stem which provides shade and oxygen and sometimes beautiful flowers or delicious fruits. So, it may not seem such a big issue to cut a tree and plant another to compensate that. After all, in some years that seedling will grow and replace completely the role of its precursor.

However, if you look closer, you’ll find that a tree is so much more than just a tree. You may see that there are other things growing on it, like epiphytic ferns, bromeliads, orchids, mosses, mushrooms, lichens, and mistletoes. And you can also find many animals eating or living on it as well, for example birds, spiders, harvestmen, insects, tree frogs, and even land planarians!

Moss and fungi growing over an orange tree. You can see some (out of focus) oranges in the background.

Moss and fungi growing on an orange tree. You can see some (out of focus) oranges in the background. Photo by Piter Kehoma Boll.*

Many invertebrate and epiphytic plant communities are highly dependent on the age of the trees, as well as on the tree species richness in forests. Saproxylic insects, i.e., those that live on dead wood, such as fungus gnats and beetles, are common in old forests. The same happens to lichens and, as they become established, they offer a range of food and nesting habitats for a lot of invertebrates.

An epiphytic fern over the same orange tree. Photo by Piter Kehoma Boll.

An epiphytic fern over the same orange tree. Photo by Piter Kehoma Boll.*

As many invertebrates associated to old-growth forest are highly specialized, having a strong link with their host tree, they are very susceptible to forest fragmentation. That’s one of the reasons why a seedling cannot replace the ecological role of an old tree.

This feather tells us a bird has passed around here.

This feather tells us a bird has passed around here. Photo by Piter Kehoma Boll.*

Some studies have also shown that the whole community of organisms associated to trees, including epiphytic plants and invertebrates from the canopy and the leaf litter around it, can be influenced by intraspecific genetic variation of trees, i.e., even trees from the same species can have different organisms on and around them depending on their individual set of genes. This has implications for the whole ecosystem, since genetic diversity of trees influence the species diversity of the community.

So the next time you see a tree being cut, remember that it’s not just a tree being cut, but a whole community being put to death. And I hope that it will make you and other people to think a little bit more before doing something that looks far more trivial than it really is.

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References:

Moeed, A., & Meads, M. J. 1983. Invertebrate fauna of four tree species in Orongorongo Valley, New Zealand, as revealed by trunk traps. New Zealand Journal of Ecology, 6, 39-53

Walsh, N. 2012. A preliminary study into the use of canopy invertebrates and sampling techniques in relation to forest indicators in a fragmented Scottish woodland – application and management. The Plymouth Student Scientist, 5 (2), 44-79

Zytynska, S., Fay, M., Penney, D., & Preziosi, R. (2011). Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem. Philosophical Transactions of the Royal Society B: Biological Sciences, 366 (1569), 1329-1336 DOI: 10.1098/rstb.2010.0183

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Friday Fellow: Corpse Flower

by Piter Kehoma Boll

ResearchBlogging.org I guess most of you already know Rafflesia arnoldii, the corpse flower, as it is quite popular for a lot of reasons. But sometimes it’s nice to show the classics too, right?

Described in 1822 by Robert Brown, the corpse flower is remarkable for having the largest flower among all flowering (and non-flowering too) plants. Its name honors its two discoverers, the statesman Sir Thomas Stamford Bingley Raffles and the botanist Joseph Arnold, who collected the first specimen in 1818. It is known from the Indonesian islands of Sumatra and Borneo, ocurring in secondary and primary forests. It is one of the three national flowers of Indonesia.

Rafflesia arnoldii. Photo by Henrik Hansson*

Rafflesia arnoldii. Photo by Henrik Hansson*

There’s a lot of other weird things about it yet to be mentioned. Its common name, corpse flower, is due to the fact that the flowers smell like rotten flesh to attract carrion flies from genera Lucilia and Sarcophaga that pollinate them. Besides that, Rafflesia arnoldii is also a parasitic plant, extracting all the nutrients it needs from the roots or stems of vines of the genus Tetrastigma, so that it doesn’t have neither roots nor leaves and passes most of its life hidden inside the parasitized plant. The only visible structure is the flower, which takes months to grow, but remains open only for a few days.

Currently, the corpse flower is not evaluated by IUCN, so that it is not labelled as threatened, but human disturbance in its natural habitat, including ecoturism, seems to be decreasing the number of flowers opening per year.

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References:

Brown, R. 1821. XV. An Account of a new Genus of Plants, named Rafflesia. Transactions of the Linnean Society of London, 13 (1), 201-234 DOI: 10.1111/j.1095-8339.1821.tb00062.x

KEW Royal Botanic Gardens: Rafflesia arnoldii (corpse flower). Available at: <http://www.kew.org/plants-fungi/Rafflesia-arnoldii.htm > Access on February 8, 2013.
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