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I find stick insects and examples of convergent evolution fascinating, so in my opinion a combination of the two makes for good reading. It so happens that such a paper was published last year and was brought to my attention by David Robinson during a recent Phasmid Study Group meeting.

Buckley et al, 2008 did a phylogenic study that involved the endangered Lord Howe Island stick insect, Dryococelus australis (Phasmatodea: Phasmatidae), a species that was previously thought extinct. Dryococelus australis is placed in the subfamily Eurycanthinae, along with the genera Eurycantha,  which has a mostly Australasian distribution around New Guinea and surrounding islands.

The study used two sections of DNA from both nuclear and mitochondrial DNA to compare the relationships between  various subfamilies and genera that were thought to be closely related to D. australis. They found that whilst the genera Eurycantha is morphologically (its body structure) similar to D. australis, they are only distantly related. One of the reasons that Dryococelus and Eurycantha were previously thought to be closely related was that both genera looked very similar and had unusually large spines on their hind legs. Now it seems that these leg spines evolved independently of each other; an example of convergent evolution.

You can read the whole article online with images of the leg spines and a phylogenetic tree.

Reference:

Buckley, T.R., Attanayake, D. and Bradler, S. (2008) Extreme convergence in stick insect evolution: phylogenetic placement of the Lord Howe Island tree lobster. Proceedings of the Royal Society B, 16th December [Online] Available at: http://journals.royalsociety.org/content/g622w01455v03763/ [Accessed 25th Hanuary 2009]

One of the species I took back from the Phasmid Study Group meeting was Mnesilochus sp., originally from Mount Apo in the Philippines. I was looking for species which at privet as I no longer have access to as many food plants as I did last and was informed that Mnesilochus will eat practically anything.

Like most phasmids you can easily see sexual dimorphism: the female is much larger than the male.

Mnesilochus sp. male (left) & female (right)

The female seems especially cryptic as she has a nobbly bit on her abdomen and usually angles her thorax when resting.

Mnesilochus abdominal extrusion

They have already started laying eggs which I shall photograph when I have better light.

Entomology News: Today BBC News had a top story titled ” Liberia worms swarm ‘emergency’ “. For a moment I was really curious, thinking they were talking about annelids before realising they meant army worms, the vernacular for particularly voracious caterpillars! The swarm of caterpillars is the worst Liberia has seen in over 30 years and they are currently undertaking aerial spraying in an attempt to control the insects.

I came across a more positive story from Monash University on some research undertaken by Dr Adrian Dyer on the responses of bees to human faces. They found that the bees could ‘average’ different views of the human face (0° and 60°) to recognise a previously unseen facial angle (30°). The research team think the study may help with the construction of AI facial recognition.

Update: You can read the full research article on bee vision at the PloS ONE website.

On Saturday 17th January the Phasmid Study Group had their winter meeting. Unfortunately I missed the AGM part but I managed to attend the two talks and got some new species to rear: Pseudophasma velutinum, P. rufipes ova and Meuseilochus sp. from Mount Apo. I will upload some photos of them soon.

The first talk was given by Mark Bushell and was a continuation of his Philippines phasmid hunting expedition. He’s a good story teller, so I enjoyed listening to his adventures and seeing the many photographs of foreign fauna. Whilst in the Philippines Mark discovered a new species of phasmid!

The second was given by David Robinson and gave a summary of the typical activities and the purpose of the International Congress of Entomology before covering some research on the phylogenetics of Dryococelus australis, the Lord Howe Island stick insect.

Dryococelus australis has quite an interesting story and I think it’s the only phasmid that has such an extensive breeding program. It used to be found on Lord Howe Island, an island east of mainland Australia. When black rats were introduced to the island, the stick insect was made locally extinct. As this was the only location that D. australis was know to occur, it was thought to be extinct. Sometime in 2001 a small colony was discovered on Ball’s Pyramid, a tiny outcrop of rock over 20km away from Lord Howe Island.

The phylogenetics paper has an example of convergent evolution and deserves its own post, so I’ll try and write a summary later this week.

There was a wonderful photograph of the castes of the ant Camponotus discolor on Myrmecos Blog.

Location: Dorothea Bate Room, Natural History Museum, London (map)
Description: Details will be in December newsletter.

See Phasmid Study Group for more details.