Let’s hear it for hoverflies Helping our pollinators

Hoverflies are frequent visitors to flowers in sunny Scotland’s pollinators are a vital part of Wasps and places in your garden, hovering around deciding our biodiversity. Species such as bees and which flower to land on. Most hoverflies feed on hoverflies are a familiar sight in our gardens, nectar, but some species such as the common Hoverflies parks and countryside. They play a crucial role marmalade hoverfly also feed on pollen. in our food and farming industries, as well as Hoverflies are the most important pollinators among contributing to our enjoyment of the outdoors flies. and our health and wellbeing

But our wild pollinators are under threat. Faced with pressures that include habitat fragmentation, changes in land use, disease, pesticides and climate change they need our help. The Pollinator Strategy for Scotland is the work of many partners. Delivering a wide range of activities it draws together the expertise and enthusiasm of a wide range of organisations, government agencies and businesses. Our main objectives are to: –– Make Scotland more pollinator-friendly; –– Improve our understanding of these vital insects Hoverfly © Lorne Gill/SNH and the services they provide; –– Raise awareness of and encourage action to help bees and other pollinating insects; and –– Monitor and evaluate whether they are thriving.

We have lots of information on how to help pollinators on our website @ www.nature.scot/scotlands- biodiversity/helping-scotlands-pollinators. Follow us on twitter @ScotPollinators And read our regular blogs @ scottishpollinators.wordpress.com/

Hoverfly © Lorne Gill/SNH Cover image: Hoverfly © Caroline Anderson nature.scot Misunderstood? Whose picnic is it?

The common wasp (Vespula vulgaris) and its close relative, Wasps may threaten to spoil your picnic, but without the German wasp (Vespula germanica), feed mostly on them, your party could have been deprived of bread, beer high-energy sugars and carbohydrates from foods such as and wine. Yeast (specifically,Saccharomyces cerevisiae) nectar and fruit. has been fundamental to baking, brewing and winemaking throughout human history. In nature, yeast cells are found The adult wasps take caterpillars, flies, spiders and beetles primarily on ripe fruits during the summer months. Since to their young, acting as a natural pest control agent and yeast is not airborne, it must rely on vectors to move from giving gardeners a helping hand. plant to plant.

When wasps hover over your lemonade or sandwich, they For years it has been assumed that birds or bees were are only interested in the food and will not deliberately responsible for transporting yeast cells, but nobody could attack you. To avoid close encounters keep food in sealed explain how they survived the winter. Italian researchers containers and put rubbish into bins. Flailing your arms Wasp © Lorne Gill/SNH suspected that wasps were involved since they feed on increases the chances of entrapping the wasp, which yeast-harbouring grapes. could then sting you. The research team analysed samples from vineyards Some people confuse hoverflies with wasps. around Italy to find several species and hundreds of Hoverflies can look like wasps or bees. This helps them strains of yeast in the wasps’ guts. Also, yeast survived avoid the interest of predators. There are over 250 species the winter in the insects’ guts, and was transferred to the of hoverfly in Britain. They can be a great ally in the garden larvae via the food regurgitated by the queen. The team as many of them feed on pests, such as aphids. believed that birds too are involved in the life cycle of yeasts, but wasps seem to be especially important.

Master engineers

Wasps build their nest with a strong, lightweight paper- like material produced by a mix of saliva and scraped wood, which is chewed up to a pulp. Hoverfly © Lorne Gill/SNH The queen kick-starts it by building a column and coating it with a chemical that repels ants. Then she builds cells around it, all in clusters of hexagonal units. Workers expand the nest by building more cells, ventilating them by vibrating their wings. The cells’ hexagonal configuration maximises strength and efficiency, as they demand the least amount of energy and building material.

Wasps are not aggressive outside the nest, however they may defend their nest if it is disturbed or threatened. If you find yourself near a nest, retreat without producing Hoverfly © Caroline Anderson Wasp © Caroline Anderson Wasp nest © Lorne Gill/SNH much vibration or noise.