Fieldwork Answers

No. Many are hoverflies, which cannot sting. Hoverflies have one pair of wings, short antennae, large eyes and often hover in place. Wasps have two pairs of wings and longer antennae.

There is no practical benefit to killing them in a garden. Harlequins compete with native ladybirds, but they also eat aphids, and they are easily confused with native species. Recording sightings is more useful.

Stickiness is usually honeydew, the sugary waste of sap-feeding insects such as aphids, whitefly, scale or mealybugs, often feeding on the leaves or branches above. Black sooty mould may grow on it.

Ants rarely damage plants directly, but they farm aphids for honeydew and drive away predators. Gently disrupting ant trails on affected stems can let ladybirds and hoverflies reach the colony.

Well-made ones can help cavity-nesting bees such as mason and leafcutter bees. Choose smooth tubes of varied size, place them in full sun, and clean or replace tubes every couple of years. Most solitary bees nest in the ground, so bare sunny soil matters too.

Protect vulnerable seedlings rather than trying to eliminate slugs. Raise seedlings until they are sturdy, water in the morning, collect slugs by torchlight, and consider Phasmarhabditis hermaphrodita nematodes in moist soil above about 5°C.

Not automatically. They can scorch leaves and kill beneficial insects on contact. Use them, if at all, sparingly on affected plants only, and never on open flowers.

Photograph it from above and from the side with something for scale, note the plant, date, time and location, and share it with community platforms such as iNaturalist or a local recording group. Treat any single answer as provisional.

Seek expert help for suspected notifiable pests or diseases, damage to large trees, structural wood damage, wasp nests near doorways, or if a valuable plant declines quickly without an obvious cause.