Observing insects: experiencing biodiversity in your own garden

Key points at a glance

• Observe hoverflies and dragonflies as natural pest controllers.
• Look out for leaf damage from leafcutter bees to identify nesting activity.
• Create food sources for specialised insects by planting native wildflowers such as wild carrot.
• Midsummer is the ideal time to document the high activity density of the insect fauna.

Why your observation counts

Biodiversity in a garden is measured not by the absence of disturbance, but by the functional diversity of the species present. In midsummer, insect activity reaches its peak. By understanding the connections between plants and their visitors, you will see how structural diversity – such as deadwood, areas of bare ground or wildflowers – stabilises the ecological balance.

Every observation is an indicator of the health of your garden. Species such as the hoverfly (Syrphidae) perform a dual function as pollinators and aphid predators, making chemical pesticides unnecessary in a functioning ecosystem.

Summer Safari: Five indicators for your garden

To assess ecological quality, these five animal groups are particularly revealing:

How to observe

1. Look for leaf damage: Check the leaves of roses (Rosa) or lilac (Syringa) for circular holes. This indicates the nesting site selection of the leafcutter bee (Megachile).
2. Use umbellifers: Plants like wild carrot (Daucus carota) are important nectar sources in July. Focus your observations here for hoverflies (Syrphidae).
3. Evening check: Search for insects on dry stems at dusk. Male wild bees (Apiformes) often spend the night motionless outside the nest.
4. Bare ground: The common darter (Sympetrum vulgatum) requires sunny, sparsely vegetated areas for thermoregulation and as a hunting perch.
5. Document structural diversity: Note if you find swallowtail caterpillars (Papilio machaon) on umbellifers. This shows that your garden also supports the larval stage of these butterflies.

Consistently avoid the use of pesticides to ensure these sensitive pollinator and predator populations are not put at risk. Natural control by beneficial insects is the only long-term, stable way to manage a garden.

Frequently asked questions

Why does the leafcutter bee cut holes in my leaves?

It does not eat the leaves; it uses the circular leaf pieces as building material to line its brood cells in the nest.

Are hoverflies dangerous because they look like wasps?

No, hoverflies (Syrphidae) are harmless. They have neither a sting nor mouthparts for biting and are important pollinators.