Hoverflies, also known as flower flies or syrphid flies, are common insects found in gardens worldwide. While adults hover around flowers, resembling small bees or wasps, their larval stage, the hoverfly maggot, plays a significant role in garden ecosystems. These maggots are beneficial due to their predatory habits, contributing to natural pest control.
Identifying Hoverfly Maggots
Hoverfly maggots range from 4 to 18 mm in length. They are legless, slug-like, and tapered, often appearing wrinkled. Their coloration varies, presenting as yellow, green, white, or brown, and their body wall is often translucent, allowing internal contents to be visible.
These larvae lack a distinct head capsule, with their head region appearing tapered. Their segmented bodies may show lines that resemble small legs. You can locate these maggots directly on plant leaves, particularly where prey like aphids are abundant.
Their Role in Pest Control
The primary benefit of hoverfly maggots stems from their predatory nature. These larvae are voracious eaters of soft-bodied insects, primarily aphids. They can consume hundreds of aphids during their development, making them effective biological control agents.
Beyond aphids, hoverfly maggots also prey on other common garden pests, including scale insects, thrips, mealybugs, and small caterpillars. This broad diet helps reduce pest populations naturally, without the need for chemical interventions.
Distinguishing Them from Other Larvae
Differentiating hoverfly maggots from other larvae is important to avoid harming beneficial insects. Unlike many pest larvae, such as housefly maggots found in decaying organic matter, predatory hoverfly maggots are usually located directly on plant foliage, often near aphid colonies. Their legless, slug-like body distinguishes them from larvae with segmented legs or a distinct head capsule.
Some hoverfly larvae, like the “rat-tailed maggot,” have a long, telescoping breathing siphon at their posterior end, allowing them to live in stagnant water. This helps distinguish them from other aquatic larvae. Unlike some pest caterpillars, hoverfly larvae lack true legs along their body.
Attracting Hoverflies to Your Garden
Encouraging hoverflies in your garden can significantly enhance natural pest control. Adult hoverflies feed on nectar and pollen, so planting a variety of flowers provides necessary food sources. Flowers with small, accessible florets like dill, fennel, cilantro, sweet alyssum, daisies, asters, and yarrow are attractive.
Providing a diverse habitat, including dense patches of flowering plants, offers food and potential nesting sites. Maintaining a continuous supply of blooms from spring through autumn ensures a consistent food source. Avoiding broad-spectrum pesticides is also important, as these can harm hoverflies and other beneficial insects, disrupting the natural balance.