Invertebrates Print E-mail

Of the million or more animal species in the world, more than 98% are invertebrates. Invertebrates do not have an internal skeleton made of bone. Many invertebrates have a fluid-filled, hydrostatic skeleton, like the jellyfish or worm. Others have a hard outer shell, like insects and crustaceans. The most common invertebrates include the protozoa, annelids, echinoderms, molluscs and arthropods.

Azure Damselfly (Coenagrion puella)

Adult male Azure damselflies have a head and thorax patterned with blue and black. They have an azure blue abdomen patterned with black markings.  Adult female Azure Damselflies have a head and thorax pattern similar to that of the male, but with dull green replacing the blue colour.

Habitat
Freshwater, small ponds and rivers

Size
2-5cm

Diet
Predators, insects

Status
Frequent

Similar Species
Common Blue Damselfly (Enallagma cyathigerum)

Common Earwig (Forficulidae)

The common earwig is predominately nocturnal in its search for food.  Though they are omnivorous, are considered scavengers rather than predators.  The forceps or cerci are used during mating, feeding and self-defence.  The females lay a clutch of 50 eggs in underground nests taking care of her young until maturity.

Habitat
Soil, leaf-litter, crevices in rocks or under bark

Size
1-1.5cm

Diet
Omnivorous, plant matter, insects, carrion

Status
Abundant

Similar Species
Little earwigs (Labiidae)

 

Common Green Grasshopper (Omocestus viridulus)

These insects are active during the day and prefer hot, sunny conditions.  The hind legs are greatly enlarged for jumping.  The jump is an escape response.  Females are larger than males, which sing by rubbing a row of small pegs on the inside of their hind femora against a hard vein on the front wings.

Habitat
Meadows, fields, heaths and in hedgerows

Size
1-6cm

Diet
Herbivores, leaves and foliage

Status
Abundant

Similar Species
Stripe-winged grasshopper (Stenobothrus lineatus)

Common Woodlouse (Oniscus asellus)

The species is nocturnal, particularly fond of rotting wood and are one of the commonest species found under garden logs and stones.  On meeting, these woodlice tap each otherís antenna as if swapping messages.  Oniscus asellus can reproduce both sexually and asexually.

Habitat
Leaf litter, compost heaps, under stones and rotting wood

Size
1-1.8cm

Diet
Scavengers, dead plant and animal matter

Status
Abundant

Similar species
Porcellionid woodlice, Pill woodlice

Earthworm (Lumbricus terrestris)

Lumbricus terrestris forms permanent deep burrows in the soil and comes to the surface to feed, unlike most earthworms, which burrow through the ground for food.  This species pull leaves into the mouth of its burrow where they partially decay before being eaten.  This aerates the soil making them a "gardener's best friend".

Habitat
Soil

Size
Up to 30cm long

Diet
Herbivore and decomposer, mainly plant matter and occasionally animal matter

Status
Frequent

Similar Species
350 species in family

 

Garden Cross Spider (Araneus diadematus)

The garden cross spider is very variable in colour, but always seems to have a cross-shaped mark on its abdomen.  The webs are built by the larger who he waiting for prey to be entangled in the web.  The prey is then captured and wrapped in silk before being eaten.

Habitat
Heath land, woodland, gardens and meadows

Size
3-16mm

Diet
Insects

Status
Abundant

Similar Species
Larinioides cornutus, Agalenatea redii

 

Garden Snail (Helix aspersa)

The adult snail bears a hard, thin shell with four or five whorls.  When active the head and foot emerge, the head has four tentacles, the upper two have eyelike light sensors and the lower are smaller sensory structures.  The muscular foot contracts to move the animal and secretes mucus to facilitate locomotion by reducing friction.

Habitat
Wide range from sand dunes, mountains, meadows and woodlands

Size
Up to 5cm

Diet
Herbivores, fruit, flowers, vegetable and cereal crops

Status
Abundant

Similar Species
350 in family

 

Five-spot Burnet (Zygaena trifolii)

The Five-spot burnet is a day-flying moth attracted to wild flowers such as knapweed.  The forewings are dark metallic green with six vivid red spots, warning predators they are toxic.  Sometimes the spots merge causing confusion with other species.  The larva is plump and hairy with variable markings, usually pale green with rows of black spots.

Habitat
Downland, meadows, woodland clearings, sand hills and cliff tops

Size
2.5-4cm

Flight Period
June-August

Larval Diet
Bird's foot trefoil and clover

Status
Often

Similar Species
Six-spot Burnet (Zygaena filipendulae) Cinnabar moth (Tyria jacobaeae)

 

Seven-spot Ladybird (Coccinella septempunctata)

The seven-spot ladybird has a broad ecological range; living almost anywhere it can find food.  The bright colours and markings are to warn predators of their poisonous or distasteful nature.  The larvae are warty with spots and moult four times before adulthood.

Habitat
Woodlands, heathland, gardens and parks

Size
1-10mm

Diet
Predators, aphis (both larvae and adults)

Status
Often (there are fears its being out competed by harlequin ladybirds)

Similar Species
5000 in family

 

Speckled Wood (Pararge aegeria)

This butterfly is characterised by a dark upper wing surface, marked with yellowish blocks and spots, some with pale centres.  The protective male will aggressively defend its territories against intruding males.

Habitat
Woodland edges and sunny clearings

Size
4-5cm (wingspan)

Flight Period
March-October in successive broods

Larval Diet
Woodland grasses

Status
Frequent

Similar Species
Wall brown (Pararge megera)