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We had a short visit recently to one of the waterways that runs through Styx Mill Reserve, in Christchurch. The ~60 ha site has an interesting mix of vegetation types (mainly wetland and riparian areas), and even some locally rare plants. But on this occasion we went to look for arthropods – both in and around the water.

Below are a few of our finds. Our thanks to the folks at NatureWatch for help with the identifications.

The forest shield bug (Oncacontias vittatus):

 

Another immature shield bug, probably a Rhopalimorpha sp.

CINJAT Rhopalimorpha sp IMG_2680

The New Zealand pond-skater (Microvelia macgregori):

 

The larvae of a mosquito/midge (Family Dixidae)

CINJAT Family Dixidae Aquatic larvae IMG_2670

A longjawed orb weaver spider (genus Tetragnatha):

CINJAT longjawed orbweaver

And this is the same spider making itself as thin as possible, presumably for hiding:

CINJAT Swamp orbweb spider Tetragnatha sp IMG_2714

There is a guide to many of the species in the reserve on the Landcare website here and the reserve is part of the Styx Project. There is also a comprehensive booklet about Christchurch Waterways available from Environment Canterbury here.

 

Gear

Scissor-lift of FischerTechnik, paint brush, shallow glass box, glif attachment, olloclip lens, iPhone, tripod, LED torch

We have been working on ways to take photographs of insects at home. Here are some of the tools and techniques we have found useful:

Camera

We have been using an iPhone 5 with the OlloClip 4-in-1 macro lens. This gives us a magnification of 15 x – which is better than many hand lenses.

Magnification inevitably results in a shallow depth of field, so achieving a clear focus requires care. The iPhone camera software allows you to lock the focus, if you tap and hold until the square yellow box flashes around your finger. The Olloclip software doesn’t appear to allow this, although it does allow you to set the focus and exposure on separate parts of the image, which is sometimes useful too.

To keep it steady, the camera is held on a tripod with a glif attachment to hold the phone on.

Photography setup

Photography setup

 

Scissor-lift

C has made a scissor-lift (out of FischerTechnik) to enable us to do fine height adjustments of the subject, relative to the camera. The lift has a threaded rod, and turning a handle moves the platform up and down relative to the camera. This degree of fine control was not possible with our tripod, but the lift ensures it is easy to make frequent small adjustments.

We have a piece of plain paper on top of the platform to give a neutral background.

Scissor-lift made from FischerTechnik

Scissor-lift made from FischerTechnik

 

Glass box

J has built a small glass container, approx. 80 x 50 mm, which stops any live subjects from roaming too far. They can still wander/skitter out of view, but it increases the chances of capturing a photograph. The box is made of 3 mm picture glass, glued together with a silicone glue (RTV). You can often get glass off cuts from a picture framer.

The sides of the box are only 11 mm high (with a glass lid on top of that) which enables us to get sufficiently close with the camera. For some creatures you can take the lid off – but for the more mobile individuals, that is not an option.

The flat sides also mean we can get clear photos from the side – unlike the distortions you get with a petri dish or a plastic container.

Any moving of the insects that is required is done with a fine paint brush.

 

Glass box

Glass box

 

Lighting

Lighting is also important. Natural light (although not direct sunlight) is sometimes sufficient, since we are using a tripod. When it isn’t, we use an LED torch.
The reason for using LED’s is that (unlike a tungsten bulb) it doesn’t produce much heat, so it doesn’t overheat the creature below.

Examples

Here are some examples of our results so far, of insects found in several Christchurch gardens:

 

'Golden green' fly

‘Golden green’ fly

Weevil

Weevil

Another flying insect

A flying insect

Praying mantis exoskeleton

Praying mantis exoskeleton

Drosophila (fruit fly)

Drosophila (fruit fly)

Monarch butterfly wing detail

Monarch butterfly wing detail

Aphids, and eggs of something

Aphids, and eggs of something

A stripy flying insect

A stripy flying insect

Lady beetle

Lady beetle

 

Other subjects

This same general setup is also useful for photographing other subjects, such as the details of plants, rocks, shells etc.

Dock (Rumex) seed capsules

Dock (Rumex sp.) seed capsules

 

Next

Some ideas we have yet to try include:

  • Try some focus-stacking software – this involves taking a series of images, each focusing on a different plane, and then the software stitches them together into a single clear photo.
  • Find some way of aligning the camera to the eyepiece of our stereo microscope, that provides 40x magnification.
  • Perfect a cooling box which will slowly cool an insect just enough to slow it down for photography, but that will also allow it to subsequently warm up and recover.
  • Build a tall narrow (approx. 11mm wide) aquatic observation tank, for photographing more of the small creatures from ponds and aquariums – something like this. And find a suitable lighting method for aquatic subjects.
Spider photographed via stereo microscope

Spider photographed via stereo microscope

 

Do you have any tools/techniques you can recommend?

 

This is Diplora, our pet praying mantis.

Diplora, with (another) meal

Diplora, with (another) meal

Exoskeletons

We have kept praying mantis’ before. Diplora joined the team when she was still very small – to start with we fed her Drosophila (fruit flies) from our compost bin.

Diplora consuming a fruit fly

Diplora consuming a fruit fly (while upside down on the roof of a glass box)

Like other insects, praying mantis’s get their shape from a stiff exoskeleton, so to get larger they shed this outer layer from time to time.

Diplora in the process of moulting

Diplora in the process of moulting

Diplora has done this 3 times since we got her and we suspect she only has one more moult to go before she (or he) becomes fully adult.

Several exoskeletons from one mantid as it grew larger

Several exoskeletons from one mantid as it grew larger

One of the interesting things about this process (ecdysis) is that the exoskeleton retains a lot of the fine detail of the mantid, but with the advantage that we are able to examine it in detail – because unlike Diplora, the exoskeleton stays still while you have a good look at it.

Exoskeleton showing the compound eyes

Exoskeleton showing the compound eyes

We have enjoyed looking at details such as the compound eyes, the spikes on the forelegs, mouthparts (mandibles) and their fine antennae.

Exeskeleton showing antennae and the eyespots on the arms

Exeskeleton showing antennae and the eyespots on the arms

Exoskeleton showing detail of forearms and an eyespot on the arm

Exoskeleton showing detail of forearms and an eyespot on the arm

Detail of abdomen

Detail of abdomen

We have not yet fully captured the process on video, but here is some footage from someone who has (for a different species of mantid).

Compound eyes and pseudopupils

One thing that puzzled us with our mantids was the appearance of black dot in each eye – which isn’t always there, depending on the light. You can see it in the photos above, especially the one at the top. This is known as a “pseudopupil” and is essentially an artefact of the viewer. The compound eyes are made of many cones, with lenses over each. The lenses reflect some light, but in one position, relative to the viewer, no light is reflected, and so a dark spot appears.

This site has a series of photos of all kinds of insects showing this effect.