Pollinating and predatory insects are an important part of a healthy garden ecosystem. Bees and other pollinating insects like Hoverflies and butterflies promote better harvests of fruiting plants and trees. Vegies like Zucchinis, Cucumbers and Pumpkins, as well as fruit trees like Apples and Oranges, need to be pollinated by the transfer of pollen around and between flowers. Predatory insects like Ladybirds, Wasps and Praying Mantis help reduce the population of damaging insects like aphids and caterpillars. So growing plants that attract pollinating and other beneficial insects in and around vegetable gardens and home orchards boost the harvest as well as help reduce levels of insect pests.
Insects also provide a valuable source of food for other garden visitors like birds and frogs. So, creating a garden that's rich in a wide variety of insect-attracting plants is beneficial for both us and local fauna.