What do they look like?
This is an immature lady beetle called a larva. It doesn’t look like a beetle, but it is a valuable aphid predator. Many, but not all, species of lady beetles are orange with black spots—some are solid black or yellow with black spots.
If you see these tiny orange maggots among aphids, you know the aphid colony is doomed. These are the immature stages of a tiny midge. They are one of our most effective aphid predators.
You have to look fast to find this quick, voracious larva eating aphids, small caterpillars and other small insects. The adult lacewing is a delicate insect with clear, heavily veined wings.
Hover flies (Syrphid flies)
These light brown, somewhat slug-like larvae are eating large numbers of aphids. Adult hover flies are shiny, yellow and black or white and black striped flies, often seen hovering like humming birds over flowers.
Aphid parasitic wasps
The rigid, pearl-like aphids in the photo above have been parasitized by tiny wasps that lay their eggs inside aphids. As the wasps develop, they kill the aphids. There are many native species of parasitic wasps—some attack aphids, while others attack caterpillars and other insects.
Minute Pirate Bugs
This is one of the many species of large and small predatory bugs. They attack flower thrips, mites, aphids and other small insects, especially in flowers.
Several species of these quick, large, purplish-black ground beetles live in local gardens. They lurk under debris and mulches, where they eat slugs, cutworms, fly maggots, cocoons of winter moths and other soil dwelling insects.
What can I do to attract them?
Even low toxicity sprays, such as soap, kill beneficial insects. To control pests, try non-pesticide methods first. If you really have to spray, minimize the harm to good bugs by spraying only the plants (or parts of plants) that need treatment.
Feed the adults
It is only the immature (larva) stages of most beneficial insects that prey on other insects. The adults feed on nectar or pollen. You benefit from the hungry juveniles when you lure their parents to your garden. Studies show that where the adults find food they stay to lay their eggs among aphids, caterpillars and other hosts. Plants that attract beneficial insects produce a rich supply of pollen or have small flowers full of nectar (see Plants to Attract Insects). Grow a variety of plants so that flowers are available to insects from all seasons. Flowers that bloom early in the spring are the most valuable to beneficial insects. Mingle the insect plants throughout the garden. They can be planted among vegetables, used in borders or in rock walls.
During the driest part of the summer, beneficial insects need a water supply. Use any type of shallow container, but place a few rocks in the water to provide safe islands so that visiting insects won’t drown.
Ground beetles and other soildwelling predators benefit from a stable environment. Cover bare soil with organic mulches or ground covering plants to provide them with a stable home while annual beds are disturbed.
Plants to Attract Beneficial Insects
Sweet alyssum is an example of a plant that is particularly good at attracting aphid predators and parasites. It blooms in as little as 6 weeks from sowing and is widely available at garden centres. Plant a border of alyssum around your rose garden and watch aphids disappear! There are many other attractive plants, including: Carrot family (Umbellifereae): dill and cilantro are quick blooming annuals; parsley flowers all season in their second year; lovage is a perennial. Cabbage family (Brassicaceae): overwintered kale, mustards and other leafy greens flower very early in the spring. Aster family (Asteraceae): calendula, feverfew and daisies of all kinds are rich pollen sources. Mint family (Lamiaceae): thymes, sage, rosemary, lavender, savory and mint flowers are rich in nectar. Other great ornamentals: yarrow, candytuft (Iberis), veronica, goldenrod, stonecrops, verbena, potentilla, heliotrope and alliums.
Tips For A Healthy Garden
© Image courtesy of Molamoni (www.flickr.com)
- Enrich the soil once or twice a year with compost or other organic fertilizers.
- Choose plants adapted to the conditions of sun or shade, moisture and soil acidity. If necessary, correct the drainage and acidity to suit the plants.
- Plant native plants, which are adapted to the local climate. Most are easy to care for and have few pest problems.
- Before buying plants, make sure they are healthy and free of diseases and insect pests.
- Water deeply, but infrequently, to encourage deep rooting.
- Cover the soil between plants and under shrubs with organic mulches. This insulates the soil, keeps in moisture and suppresses weeds.
- Protect and attract native beneficial insect, birds and other animals.