What is an Invertebrate:
Many
members of the general public feel that any 'creepy crawly'
is an insect or a bug but very few understand what an invertebrate
is and how many different forms there are.
An invertebrate is literally an 'animal without a backbone'.
Invertebrates, which includes insects, bugs and many other forms
of creepy crawly, do not have bones inside their bodies like
humans and other mammals; they have no solid internal structure
on which to hang their soft bits. Instead, they have a hard
outer shell made of a substance called 'chitin', a brown, hard,
organic compound, inside which their soft bits are either hung
from pegs and protuberances or else 'slosh around' like beans
in a can. This means that instead of lots of blood vessels (arteries,
veins and capillaries) to transport oxygen and food to the organs
in their bodies most of their organs are awash in a sea of their
blood (called haemocele) and consequently their hearts are small
and relatively weak as they only need to 'stir' the blood pool
rather than 'pump' it around a large body.
Invertebrates, apart from the lack of a backbone, have many
differing lifestyles and have evolved body structures to cope
with those lifestyles This can range from many hundreds of legs
to no legs at all; from being winged to having no wings or having
lost wings; from having a shell to not having a shell; from
being herbivorous (plant-eating) through being omnivorous (eating
plants and animals) to being carnivorous (meat eating) and many
other differences as well.
Different Types of 'Other' Invertebrate:
The invertebrates most often studied are insects; these have
six legs and three body parts (head, thorax and abdomen) with
the legs always being attached to the thorax. However there
are many other forms of invertebrate. For example:
- Insects:
- Bees, Wasps, Ants, Ichneumons, and Sawflies - (Hymenoptera)
- Beetles (e.g. ladybirds, ground beetles, etc.) - (Coleoptera)
- Flies (e.g. hoverflies, craneflies, robber-flies, horseflies,
midges, etc.) - (Diptera)
- Bugs (e.g. shield-bugs, aphids, frog-hoppers, etc.)
- (Heteroptera)
- Dragonflies and Damselflies - (Odonata)
- Lacewings, Scorpionflies, Snakeflies and Alder Flies
- (Neuroptera)
- Moths and Butterflies - (Lepidoptera)
- Earwigs - (Dermaptera)
- Grasshoppers and Crickets - (Orthoptera)
- Springtails - (Collembola)
- Stoneflies - (Plecoptera)
- Caddis-flies - (Trichoptera)
- Mayflies - (Ephemeroptera)
- Book-lice - (Psocoptera)
- Bristle-tails (e.g. Silverfish) - (Thysanoptera)
- Fleas - (Siphonaptera)
- Arachnids:
- Spiders
- Mites - (Acari)
- Pseudo-Scorpions
- Harvestmen
- Molluscs:
- Snails
- Slugs
- Bivalves (e.g. mussels)
- Annelida:
- Worms (e.g. earthworms)
- Flatworms (e.g. New Zealand Flatworm)
- Leeches - (Hirudinae)
- Crustacea:
- Woodlice - (Isopoda)
- Freshwater Shrimps - (Amphipoda)
- Myriapods:
- Centipedes - (Chilopoda)
- Millipedes - (Diplopoda)
Many
more types of very small invertebrates exist (such as the copepods
which swim in ponds and streams) but study of these is beyond
the scope of this web-site being more allied to microscopy workers
using compound microscopes rather than the stereo microscopes
used by entomologists. A great deal of assistance with the study
of insects and other invertebrates can be obtained by joining
a regional/local entomological group such as the Lancashire
and Cheshire Entomological Society (LCES) or a national
entomological group such as the British
Entomological and Natural History Society and/or the Amateur
Entomologists' Society, or by contacting your Local Record
Centre (e.g. rECOrd
- The Cheshire LRC)
Invertebrates Within Cheshire:
Cheshire as both a Modern (post-1974) Authority structured
county including the areas of Halton and Warrington above the
River Mersey in what used to be South Lancashire and also as
the much larger Watsonian Vice-County (VC-58 - Cheshire) which
includes the Wirral and the 'pan-handle' around Stockport and
Tameside has examples of all of the above types of invertebrate
within its borders. Some of the groups such as the Lepidoptera
(Butterflies and Moths), and the Odonata (dragonflies and Damselflies)
are very well studied indeed and the distributions and life-cycles
of the species within the county are well understood. However,
other groups such as the mites (Acari), the worms (Annelida)
and the Book-lice (Psocoptera), amongst many others, are very
little known at all.
Should you study any group of invertebrates within the Cheshire
and South Lancashire areas I would be very pleased to hear from
you and to aggregate your observation records to enable us to
better understand the distribution and biology of invertebrates
within the region. Many thanks for your help.
NEW: Cheshire Moth Group:
Towards the end of 2001 a new Cheshire Moth Group came into
formation to progress the recording of all moths within the
Cheshire region and to work towards an atlas covering both macros
and micros within approximately five years from 2002. Another
aspect of this group will be the formation of a Moth Panel to
vet records from recorders each year in a similar vein to the
panels which have been run by bird-watchers (ornithologists)
for the past ten years or so.
Currently the people involved are Adrian Wander, Paul Hill,
Steve McWilliam, Steve Hind, Shane Farrell, Eric Kearns, Kevin
McCabe, Jeff Clarke and Phil Rees.
For further details please contact Adrian
Wander.
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