You may have heard, or even noticed, that there is a shortage of wasps about this year. This is thought to be due to the colder and wetter weather we have had this year, along with the ongoing problems caused by climate change. Although they can be really annoying in autumn, they are an important component of our ecosystem and I hope their numbers pick up again next year. When we talk about wasps, we are usually referring to the common social wasps that live communally in large nests containing up to 10,000 individuals. However, these social species represent less than 1% of the total wasp species. I was fortunate to encounter one of the solitary species in my back garden recently, a rare insect known as Lestiphorus bicinctus. These are usually found in the southern counties of the UK and this may be the first one to be seen in Leicestershire. It is a member of the group known as ‘Digger Wasps’, so-called because the female wasp digs a tunnel in soft or sandy soil in which to lay her eggs. The burrow may be up to 30cm in length and may be branched at the end. The female wasp will capture her prey by stinging it and then storing a suitable insect in each of the branches of the nest. The picture here shows a captured bug underneath the wasp. After stocking the nest with suitable food, she will lay an egg in each branch; the egg will hatch and the wasp larva will consume the insect. For many species the single insect will be sufficient for the wasp to grow to full size, but for some species the adult female returns with a further supply of food.

Although the digger wasps are around half of the size of our common social wasps, many solitary wasps are very much smaller – indeed, the world’s smallest insect is a wasp known as the Fairyfly, just 0.14mm long. Too small to see clearly, but often these tiny insects can be found easily as they cause plants to form galls where the eggs are laid. One of these is the Knopper Oak Gall Wasp that can be found commonly on Oak trees. When the wasp lays its egg the tree forms a gall around the egg; these are often red or yellow (as in the example shown here) or may be various shades of green and brown. The wasp larva completes its development within the safety of the gall and the resulting adult burrows its way out. This species arrived in Great Britain in the 1960s and has since spread throughout England and Wales.

Bees and wasps are often confused, particularly when looking at the solitary rather than social species, but generally speaking bees are hairy and wasps are shiny. One species of solitary bee that I see in my garden each year is the European Wool-carder Bee, easily recognised by its pattern of bright yellow spots on the sides and tip of the abdomen. The reason it comes to my garden is to take advantage of a particular plant – Lamb’s Ears (Stachys). Female bees of this species scrape the hair from the woolly leaves of the plant to furnish their nests.

I think that wasps and bees will probably never feature in a list of favourite animals, largely due to unsocial behaviour of our social wasps. However, most will not sting unless their lives are being threatened, and many species do not possess a sting. Bees are widely regarded as useful due to their value as pollinators, but wasps have their uses too. They are predators that are essential to keep other invertebrates in check, such as spiders, insects and woodlice. It has been estimated that each colony of wasps removes at least 250,000 aphids from your garden each year, as well as many other pests. Much better to leave pest control to these guys rather than spraying toxic chemicals everywhere.