As Halloween approaches, spiders, cobwebs, bats, pumpkins and all things spooky will be taking centre stage! The autumnal months are certainly the best time to spot spiders, as late summer and early autumn are mating season for spiders.
But how much do you know about the spiders we might find in our homes and gardens? This week we take a closer look at just a couple of the approximately 650 species of spider in the UK. Despite their feared reputation, only around 12 of these UK species bite, and only 2 or 3 can cause any significant harm. Our most harmful species is the noble false widow - a new arrival in the south, probably as a result of climate change. This species can cause a painful bite and flu-like symptoms, but rest assured that such cases are extremely rare indeed!
A species commonly found in gardens is araneus diadematus, known by many names such as garden spider, European garden spider, cross spider or cross orb-weaver spider. As these last names suggest, it spins large orb shaped webs (what we would think of as a typical spider's web), up to 40 cm across. This spider is mature from summer to autumn. If you spot a female around now, it is likely to look particularly large and bulbous! This is because in late autumn they are at their oldest and are often full of eggs. After laying their eggs the females die and only the eggs and the spiders that hatched in the spring of the year will overwinter. This spider can be identified by a distinctive white cross on the abdomen, although its overall colour can vary, ranging from red-orange to almost black.
Female Araneus diadematus, full of eggs. Spotted this week by a pupil at a primary school local to Flatford.
Photo: Sarah Kent
Another orb spider that spins a big, cartoon style spider's web is the wasp spider. This spider is a recent arrival from the continent, but has now spread across much of southern England. The female's wasp like appearance deters predators, while the male is smaller and less showy. In the middle of the wasp spider's web is a mysterious zig zig called a stabilimentum. The function of this zigzag is uncertain, but may reflect UV light and attract pollinating insects such as flies, bees and moths. Another theory is that it helps to camouflage the spider.
Life for the male wasp spider is a risky business, as they often get eaten by the females after mating! The males wait at the edge of the web until the female has moulted into a mature form, then take advantage of her jaws being soft and rush in to mate. Unfortunately this cunning plan often fails and the males are frequently eaten anyway. The body provides valuable protein for the female, who will then produce eggs. Once mated, the female lays her eggs and then spins a large, flask-shaped, brown egg-sac, somewhat resembling an upturned Greek urn. This is generally hung in or near her web. Females die in the autumn. Young hatch from the eggs before winter, but do not emerge from the egg-sac until spring. The young spiderlings then grow and mature throughout the spring and summer.
This female wasp spider Argiope bruennichi spun a web across a trampoline handle in our garden in September. Note the egg sac and the stabilimentum zig zag.
Photo: Julia Walshaw
As well as spotting fascinating spiders, there are plenty of nature-based activities to keep the family busy this half-term and Halloween. Flatford Autumn Nature Day, a joint collaboration between the organisations that call Flatford home, is on October 24th. And at Flatford Wildlife Garden, children can find out all about Bewitching Bats! Follow the garden trail to find out about brilliant bats, then craft your own flying bat to take home. The cost is £2 per child, plus a £5 parking charge if you're not a National Trust member.
Sadly the end of the season is approaching as Flatford Wildlife Garden prepares to close its gates for the winter (with the exception of a few special events...) So make the most of these last opportunities to enjoy the sights, sounds and smells of autumn in the garden. Open every day until 30th October, 10:30-4:30.