Posts Tagged ‘PSG’

Cheap Digital Microscopy

Thursday, April 23rd, 2009

Whilst most of the specimens I photograph are over 5mm long, I am finding that anything smaller does not have enough detail when I use my macro lens. My subjects are small insects in the field and small parts of (sometimes small) museum specimens. I am fairly certain that extension tubes will do the job for the leafhopper-sized insects and probably Collembola, but my museum work seems to be heading towards getting a digital microscope.

My supervisor and I have been looking at reasonably priced attachments and whole systems, but have yet to come close to reaching a decision. Unexpectedly, there was an article in The Phasmid Study Group newsletter (which arrived today along with the British Dragonfly Society newsletter and journal) about a cheap USB microscope. The model featured was a Summit Microfix Digital USB Microscope which can be purchased for <£50 on Amazon.

Although it is hard to see exactly how good the images produced by the microscope are, I can make out stick insect individual ocelli and fine hairs on the antennae. Whilst I think the image quality looks good enough, I am uncertain how easy it would be to increase the limited depth of field by “stacking” multiple images. From the photos of the microscope, it does not look like it comes with a stand. Amazon reviews of other microscopes made by what looks like the same company are not entirely favourable, with some potential driver issues for Mac and some XP users.

I will try and contact the author to see if it would be easy to attempt depth stacking and to have a look at her images in more detail.

Mnesilochus sp. & Two News Stories

Tuesday, January 27th, 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)

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

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.

Phasmid Study Group: Summary of Winter Meeting

Monday, January 19th, 2009

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.

PSG: AGM & Winter Meeting

Sunday, November 30th, 2008

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

See Phasmid Study Group for more details.


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