This month's features in our summer
The author of these walks regularly suggests that readers carry a 10X hand lens on a walk to admire nature in close-up...... particularly at this time of year, when the countryside is full of flowers in bloom and insects to study.
This month, none of the subjects studied in close-up require a microscope at all, just that 10X hand lens ...... and if you have a camcorder or still camera with a rarely used 5-10X macro capability why not take it with you on a walk and take some close-ups! Two articles in 'Further Reading' provide more information on buying and using a hand lens.
Please read the important notes on collecting.
Everyone admires flowers, whether in the garden, ornamental park or in the wild. The beauty of the larger flowers such as roses and tulips can be appreciated without any magnification aid. But those smaller flowers that are barely 5-10mm across often have wonderful shapes, colours and textures that can be overlooked unless you look closely with a lens.
For example, the Forgetmenot (Myosotis) shown at the top of the page is a common flower in both wild and urban areas, and is in flower around the author's garden pond at the moment. The flowers are only 8mm across, but in close-up they are beautiful! A 10X lens will reveal the wonderful detail shown left (note the aphid on the flower).
Another small flower that is attractive in close-up is the Speedwell (Veronica). There are a number of wild species with delicate blue flowers, but the garden varieties such as the one right from the author's garden are also worth studying. Note that whereas the anthers of the forgetmenot are almost enclosed within a tube formed by the fused petals, the speedwell's anthers are not enclosed. (The anthers are the pollen- bearing structures on the stamen, the stalk which carries them).
Many larger flowers also have easily overlooked detail in their flower structure. The Foxglove (Digitalis) for example, which is in flower in the author's area at the moment, is a tall plant with spikes of pink-purple bell-shaped flowers 4-5cm long. If a flower is split open, the patterning on the inside of the flower (right) and the detail on the unopened anthers which carry the pollen can be seen (left).
Studying the structure of flowers can give you a valuable insight into the botanical distinctions between plants of different families, and may create an interest in identifying wild flowers. For example, the clover (Trifolium) the low growing flower in grassland and the lupin (Lupinus) a tall plant with spikes of typically blue flowers, bear no obvious resemblance. However, inspection of the flowers with and without a lens will show that they have a similar structure, because they are both members of the pea family (Leguminosae).
At this time of year the larvae of butterflies and moths can be seen on their respective food plants. The larvae are often attractive and worth studying in close-up. Hundreds of the larvae (caterpillar) shown left were eating their way through the leaves of the dwarf willow (Salix sp) in the author's garden. Only the midribs of the leaves were left by the time they had finished!
A typical caterpillar has three pairs of true legs at the front, which are just visible in the image, and five pairs of stumpy or fleshy prolegs at the back. The last pair are known as claspers. All the prolegs have numerous minute hooks, with which the caterpillar keeps a firm hold on the food plant.
Another common sight in the author's area at this time of the year is frothy masses on the stems of plants. You may have noticed them many times yourself, but have you ever stopped to examine what is inside this froth? It is produced by the nymph (see Footnote 1) of the froghopper which is also known as the spittlebug or cuckoo spit. The nymph can be seen in the froth on the image right. It is facing downwards, and the yellow abdomen and one of the two reddish eyespots on the head are visible.
The nymph produces the froth by secreting a fluid through the anus that is mixed with a secretion from the abdominal glands. Air bubbles are introduced through a special valve on the abdomen to create the froth (or spittle) that protects the larva from predators and desiccation.
Froghoppers are bugs, and the adults which are less than 15mm long, have some resemblance to a frog and are powerful leapers. Although 'bug' is often used loosely to describe any insect, it more correctly describes a distinct order of insects (see Footnote 2) whose characters include piercing mouthparts through which the insect sucks juices from the plants or animals on which the bug feeds.
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Footnotes on the froghopper section
1) A nymph is a sexually immature form usually similar to the adult and occurs in a number of insect groups. In contrast, a larva is also an immature stage before the adult (not just in insects) but it bears no resemblance to the adult. For example, the caterpillar is the larva of the butterfly and moth.
2) Froghoppers belong to the insect order Homoptera. This order is considered by some taxonomists a sub-order of the order Hemiptera and a separate order by others. The family to which the froghoppers belong, the Cercopidae, is referred to as the Aphrophoridae in some older textbooks. Confused? .... so is the author!
Read an article 8X Everything in the July issue of Micscape by Maurice Smith. This illustrated article gives advice on what hand lens to buy, what to look at and even how to take video or still pictures through it!
Read an article in the Micscape library on Using your camcorder as a microscope by Maurice Smith. This provides an illustrated introduction on how to use your camcorder for close-up filming.
The structure of plants and their flowers should be covered in an introductory guide to botany or a good illustrated identification guide to wild flowers of your region. Encyclopaedias should also give a good introduction to the structure of flowering plants.
There are a wide range of books on insects, particularly the more popular groups like butterflies and moths. A good example of a general guide is Collins Guide to the Insects of Britain and Western Europe by M Chinery. ISBN 0 00 219137-7.
Note that general guides of this type only indicate representative species or those most likely to be found for groups such as beetles and flies, because of the large number of species in some insect groups.
The flower images were taken using a CCD camera with a 50mm
SLR camera lens and extension tubes attached and the screen
magnifications are between 5-7X . The close-up of the Myosotis
is magnified 20X and was taken with the CCD camera attached to a
stereo microscope with no eyepiece using a 1X objective.
Camera images were transferred to the PC using a Creative Video Spigot capture card.
Image manipulation using Photostyler v2.0 software.
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The author Dave Walker
is a UK based amateur naturalist keen to encourage people to
explore nature in close-up.