It was peak of monsoon. Rain was pouring outside The weather was hot and humid. My daughter noticed some very small white bugs all over our bed room wall. They were very very tiny less than 1 mm in size. At first I thought it was a fungus growth as the weather was humid and we had left the windows and doors open for fresh breeze of air. But soon we realized that these tiny white objects started moving. I took out a magnifying glass and when looked under that I realized that we were invaded by these small insects. There were thousands of these small insects all over the wall laying eggs, some of them hatching, few in their very young nymph state and few just started to sprout wings.
I took my Canon EOS 5D Mark III and tried to take the picture using Canon EF 100mm f/2.8L Macro IS USM. Even at 1:1 resolution I found the picture too small as the insects were so tiny. Just to make you aware of their size just have a look at the last picture on this page that was clicked using 100mm f/2.8L Macro IS USM at minimum focus distance thus yielding 1:1 magnification. When I zoomed in using Live view I saw to my horror a female insect freshly laying her eggs on the wall. I wanted top capture them in full magnification. SO I took out my Canon MP-E 65mm f/2.8 1-5x Macro and fitted it in 5D mark III. For illumination I used Canon MT-24EX macro twin light flash which was the only way to illuminate for that lens. I was using my LED headlights to focus and photograph these tiny critters. All the bigger photos of the Bark Lice here are taken at 4X (1:4) magnification.
The Canon MP-E 65mm Macro Lens is an extreme macro lens unlike any other lens. This lens starts where typical macro lenses stop. Canon MP-E 65mm Macro Lens is a manual focus lens. Turning the focus ring does indeed bring the subject into focus, but this effect zooms in and out on the subject. You can either set the magnification you desire and move closer/farther away to focus (magnification priority), or you can change the magnification by turning the ring until your subject is in focus.
Well, it will focus on your subject as long as you are within the Canon MP-E 65mm Macro Lens’ tiny focus distance range. Starting at 1x, the MP-E subject is in focus at a slightly more than a 100mm working distance. By 2x, the working distance drops to 63mm. Continuing on a distance curve, the MP-E allows only 41mm of working distance at 5x. DOF on the Canon MP-E 65mm Macro Lens ranges from 2.240mm (1x, f/16) to .048 (5x, f/2.8). At 5x and f/16, the MP-E gives a minute .269mm DOF. This sounds worse than it really is as a grain of rice (says Canon) can fill the viewfinder. Subjects this tiny generally do not need as much DOF as something like a flower.
The Canon MP-E 65mm Macro Lens is advertised as an f/2.8 lens. And it can be set down to f/16. F/2.8 is fast, but many lenses can be stopped down well beyond f/16. Well, truth is, the manual gives a chart of the “Effective” apertures for this lens. To calculate these, use this formula – Effective Aperture = (Aperture Setting) + (Aperture Setting x Magnification) So, even selecting f/2.8 at 1x magnification results in an effective f/5.6. Selecting f/16 at 5x results in an effective f/96. Selecting f/5.6 at 3x results in an effective f/22.4. Get it? In reality, the camera takes care of this effective aperture change with its auto exposure. What you will notice is that the viewfinder gets very, very dark by 5x magnification. To make this worse, you are often shading the subject with the very-short working distance setup. With effective apertures this tiny, a huge amount of light and/or a long shutter speed is required for adequate exposure. Another issue is the jitteryness of the camera at these magnifications. Basically, you will need an very stable tripod and a motionless subject – or you need a flash.
The insect which was on the wall was Bark Lice or otherwise called Psocids. It belongs to Psocoptera order of insects. This particalr Bark Lice belongs to Caeciliusidae Family which is commonly know as Lizard Bark Lice. Psocids are small, scavenging insects with a relatively generalized body plan. They feed primarily on fungi, algae, lichen, and organic detritus. They have chewing mandibles, and the central lobe of the maxilla is modified into a slender rod. This rod is used to brace the insect while it scrapes up detritus with its mandibles. They also have a swollen forehead, large compound eyes, and three ocelli. Some species can spin silk from glands in their mouth.
The forewings are up to 1.5 times as long as the hindwings, and all four wings have a relatively simple venation pattern, with few cross-veins. The legs are slender and adapted for walking, rather than gripping, as in the true lice. The abdomen has nine segments, and no cerci. The young are born as miniature, wingless versions of the adult. These nymphs typically molt six times before reaching full adulthood. The total lifespan of a psocid is rarely more than a few months.
Most psocids live outdoors and have wings. They can be found on tree bark, tree and shrub foliage, or under stones. They sometimes can become quite conspicuous when they congregate in large groups. Bark lice feed on fungi, lichen, pollen, decaying plants, and other organic material. They are harmless to plants and no control is necessary. The most effective method for controlling is to reduce moisture. Most psocids do not survive when humidity falls below 50%. A dehumidifier or fan is effective in reducing moisture. Sometimes airing out a room to keep the air moving may be sufficient. As soon as I closed the room and used air conditioner to decrease the humidity they started moving out of the room and went away.