The Other Beneficial Insects – April, 2014

This month we’re looking beyond the pollinator garden, to that other garden many of us are feverishly planting this time of year: the vegetable plot.

Even as we start dreaming of giant pumpkins and heirloom tomatoes, we know the pests of those plants are looking forward to the harvest as much as we are. And because we care about protecting pollinators, we loathe using insecticides.

One strategy for tipping the odds back in our favor is attracting the predators and parasites of those pests—the other beneficial insects. Lacewings, flower flies, and tiny solitary wasps are just a few of the common beneficial insects that can be easily drawn to almost any vegetable garden, making a huge contribution to the natural control of pests.

The most important step you can take to attract these other beneficial insects and grow their populations is to provide them with food even when their prey are scarce. In many cases the food these insects depend upon when not attacking pests is the same food that bees use: nectar, and occasionally pollen.

Unlike bees, however, many of these other beneficial insects have tiny mouths and need special flowers from which they can successfully feed. In general, shallow disk-shaped flowers and open umbrella-shaped inflorescences made up of many tiny flowers are the most attractive to garden predators and parasitoids. With this in mind, native wildflowers in the sunflower, carrot, and mint families are good bets for planting in border areas around the vegetable garden to attract these helpers.

In the garden itself, we encourage companion plantings with herbs in the carrot family like dill, fennel, cilantro, anise, caraway, lovage, and others. Planting these species directly in rows with other vegetables and letting them flower is typically a very successful way to attract large numbers of beneficial insects. One final tip: by starting some of these herbs earlier than your vegetables, you can have a few flowering early in the season and already attracting beneficial insects before the pests arrive!

Be on the lookout for Xerces’ upcoming book, Farming with Native Beneficial Insects, which you’ll be able to buy in August.

To read previous months’ tips, please click here.