Rosemary Winnall MBE, from Wyre Forest Study Group, gave a fascinating talk in April, all about her fascination with insects! The group is dedicated to surveying, studying and recording the wildlife and ecology of the Wyre Forest, including its insect life.
What are Insects?
Insects are arthropods: invertebrate animals with segmented bodies and jointed limbs. Insects are distinguished from other arthropods (spiders, centipedes etc) by the adult having a separate head, thorax and abdomen and 3 pairs of legs. However, insects have complex life stages before they take on their adult form. Most hatch from eggs and may go through several stages including moulting or pupating before emerging as fully mature adults. Because of this multi-stage life cycle, juvenile insects can look very different from the adults they become.
Despite their small size some insects are diligent parents. Social insects like bees, ants and wasps care for their offspring throughout their development. Other parents may restrict their efforts to finding the best possible spot to lay their eggs. Even among non-social insects there are some that stay by their eggs and young to protect them: earwigs look after their eggs all winter and feed the young just after they hatch; the parent shield bug sits over and protects her eggs and stays close by even after they hatch.
Typical habitats that the Study Group survey for insects include animal dung, dead wood, sandy areas and flower-rich areas. Water is an important habitat for many insects, either as adults or as juveniles. There are also many night-flying insects including moths that the Study Group periodically traps to record species and numbers.
Insect numbers are falling due to loss of habitat and climate change. It is important to keep monitoring the local species as some typical insects disappear from an area while others may arrive. All the Study Group’s findings are updated into iRecord (see Useful Links).
Insect Species
Rosemary described some of the 20,000+ species of insects that can be found in the UK. Worldwide there are millions of insect species, the exact number unknown since many will be undiscovered.
MayFly
The 51 species spend about 2 years in water as nymphs before a two-stage transition to adulthood. Known for their short lives as mature adults, the males have large eyes to help them locate a mate.
Dragonfly & Damselfly
58 (possibly 59) species live for 2 years in ponds or other slow-moving water bodies, The nymphs are voracious predators on aquatic life. The Emperor dragonfly loves new ponds and is quick to colonise them. The adults are often eaten by birds.
Grasshopper and Cricket
The 2 can be distinguished by the length of their antennae: grasshoppers have short ones and crickets have long ones! The Southern Oak Bush Cricket was previously only found in the south but has recently been noted in Shropshire.
Earwig
The male has curved claspers and the female has straight claspers. It is the female that takes such good care of her young. NOTE: Earwigs are beneficial insects used by gardeners to protect fruit trees.
Bugs
There are about 2000 UK species of true bugs.
Shield Bugs moult several times and can look different each time, but distinguished by the triangular shaped “shield” on their back.
Stilt Bugs can be identified by their long slender legs. The Enchanter’s Nightshade Stilt bug is an example of an insect with a very specific food source.
Bark Bugs are extremely flattened bugs, coloured to camouflage themselves on tree bark.
Water Bugs include back swimmers and the predatory Water Scorpion.
Homopteran (hopping) Bugs include Froghoppers, Treehoppers, Leafhoppers and Planthoppers: all jump to avoid predators or to move between plants.
The 630 species of Aphids are often specific to 1 plant (e.g. Giant Willow Aphid, Water Lilly Aphid) and reproduce rapidly in spring. They can then grow wings and fly off to a second host plant. All gardeners are familiar with greenfly, whitefly and blackfly, but help is at hand among the Lacewings and Beetles!
Lacewings and Related Species
There are 70 species of Lacewings as well as similar species of Alderflies, Scorpionflies and Snakeflies. All are beneficial garden insects that eat other (not so beneficial) insects, particularly aphids!
Lacewings lay their eggs on threads underneath leaves. They over-winter as adults. Larvae of some species carry bits of their prey on their backs as camouflage. The Giant Lacewing flies at dusk in the Wyre Forest.
Beetles
There are more than 4,000 UK species of beetles including 55 species of Ladybirds (we’re all hoping for another good year for Ladybirds to keep those pesky aphids in check!).
The beetles also include 613 species of weevils, some of which may be responsible for problems if you grow plants in pots.
Oil beetles – larvae (triungulins) hatch from eggs and climb up plant stems into the flowers. When a solitary bee visits the flower the larvae attach themselves to the bees back and are taken back to the bee’s nest where they feed on the bees eggs.
Butterflies, Moths and Similar Species
There are 72 species of butterfly which includes some of our most beautiful insects (as well as the less-welcome Cabbage White species!).
The Holly Blue Butterfly is unusual in that they alternate the food source for their caterpillars: the first (Spring) brood lay their eggs on Holly flower buds while the second (Summer) brood lay their eggs on Ivy.
There are 887 species of moths and 1500 species of micromoths.
Micromoth larvae are tiny, such as the leaf miners that live between the lower and upper surface of leaves
Not all moths are night-fliers: the Six-spot Burnet is a common daytime flying moth.
The Winter moth is active during the cold months: the female is wingless and releases pheromones to attract males. Caddis Flies are closely related to moths and spend most of their life as aquatic larvae. Some species lay their eggs above water so that the larvae drop into the water once hatched.
True Flies
A large group of insects with only 1 pair of wings. True flies include Midges, Mosquitoes and Horse flies as well as the more harmless Crane flies.
The 283 species of Hoverflies are beneficial in the garden, both for pollination and pest control.
The Bumblebee Mimic and the Hornet Mimic may look like their stinging namesakes, but they are harmless to humans. The Great Pied Hoverfly lays its eggs in wasp nests where the larvae feed on debris.
We’re all familiar with the Blow Flies that annoy us in the summer. Gall flies lay their eggs on specific plants inside protective galls that protect the larvae.
Hymenoptera (Bees, Wasps, SawFlies, Gall Wasps and Ants)
There are 7,760 species of hymenoptera.
Saw flies can be distinguished by having no waist and their larvae have pseudo legs (unlike caterpillars).
Wasps include social species that form large papery nests as well as solitary Digger wasps that live in individual burrows in sandy soil or lawns. Wasps provision their nests with animals, unlike bees that rely on nectar.
There are 259 species of bees including social bees like Honey bees and solitary bees (e.g. Mason bee, Mining bee, Carder bee). Solitary Ivy bees time their emergence to coincide with ivy coming into flower and are extending their range northwards.