Physical Description

Micromus variegatus, commonly known as the Brown Lacewing, is predatory during its larval and adult life stages.

• Adults are approximately 8 mm (0.3 inches) in length. They are pale brown in colour, with long antennae and oval-shaped wings that are covered in small hairs. 

• The eggs are pale brown and are typically laid at the base of plants or on foliage.

• Larvae of Micromus variegatus are approximately 10 mm (0.4 inches) long. They have large, forwardly projecting jaws and well-developed legs. 

• Pupae are usually separate from each other, but sometimes appear in groups in areas of high aphid population density. 

Life Cycle

Micromus variegatus completes its life cycle within 25 to 30 days at temperatures around 24°C (75°F), through four stages: egg, larva, pupa, and adult. This species is adaptable and can remain active at temperatures as low as 4°C (39°F), making it effective in cooler environments.

• Eggs hatch after approximately 7 days.

• Newly hatched larvae are cream, gray, or white-coloured, with two lengthwise brown or reddish stripes or rows of spots. Each larva can consume a significant number of aphids and other soft-bodied insects during its development, through three instar stages over approximately 2 to 3 weeks. 

• The pupal stage lasts about 10 to 14 days, after full-size larvae spin round, silk-like cocoons in the canopy.

• Adults females begin laying eggs around the 5th day after emergence, with peak egg-laying occurring between 9 to 23 days post-emergence. Females may lay up to 100-150 eggs during their lifetime.

Mode of Action

Micromus variegatus larvae and adults are voracious, nocturnal predators that search for prey. The larvae and adults grasp their prey from below and lift them in their jaws, injecting the prey with a salivary fluid that digests the body contents, which are then sucked out. Adults can consume up to 100 aphids per day, and larvae can consume between 5-80 aphids per day during its development. 

Target Pests

Aphids including

• Potato Aphids Macrosiphum euphorbiae

• Foxglove Aphids Aulacorthum solani

• Green Peach Aphids Myzus persicae

• Cotton-Melon Aphids Aphis gossypii

• Strawberry Aphid Chaetosiphon fragaefolii

• Cannabis Aphid Phorodon cannabis

• Chrysanthemum Aphid Macrosiphoniella sanborni

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Thrips Larvae & Adults including:

• Western Flower Thrips Frankliniella occidentalis

• Pepper Thrips Thrips parvispinus

• Onion Thrips Thrips tabaci

• Impatiens Thrips Echinothrips americanus
   

Whitefly Eggs & Larvae including: 

• Greenhouse Whitefly Trialeurodes vaporariorum

• Silverleaf Whitefly Bemisia tabaci

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Spider Mites including:

• Two-Spotted Spider Mites Tetranychus urticae