Watch YouTube Video on a Biological Control Agent: Green lacewing
Role of Green Lacewings in Biological Control
Green lacewings (Photo 1) are among the most beneficial insects in agro-ecosystems and gardens. Chrysoperla rufilabris, commonly known species of the predatory green lacewing, is widely used in biological control programs because of its voracious appetite for soft-bodied insect pests. Understanding its biology and predatory behavior helps growers, landscapers, and gardeners use this natural enemy more effectively.
Identification and Taxonomy
Adults are delicate, pale green insects with long (Photo 1), slender bodies, golden compound eyes, and transparent, lace-like wings held roof-like over the body. Eggs are distinctive and laid singly at the tip of long, hair- like stalks (Photo 2) that reduce cannibalism among newly hatched larvae.
- Order: Neuroptera
- Family: Chrysopidae
- Species: Chrysoperla rufilabris
Life Cycle and Biology
Chrysoperla rufilabris undergoes complete metamorphosis with four life stages:
- Egg: Eggs hatch in 3–5 days under warm conditions (Photo 2).
- Larva: The larval stage, often called the “aphid lion,” is the primary predatory stage. Larvae are elongated, mottled brown, and equipped with sickle-shaped mandibles for piercing prey and sucking out body fluids (Photo 3).
- Pupa: After 2–3 weeks of feeding, larvae spin a silken cocoon and pupate.
- Adult: Adults live several weeks, feeding mainly on nectar, pollen, and honeydew (Photo 4). Females lay hundreds of eggs during their lifetime.
Development time varies with temperature, allowing multiple generations per year in warm climates or protected environments such as greenhouses.
Feeding Behavior and Target Pests
Green lacewing larvae are generalist predators that attack a wide range of soft-bodied pests, including:
- Aphids (Photo 2)
- Whiteflies (Photo 5)
- Thrips
- Mealybugs (Photo 3)
- Spider mites
- Small caterpillars
- Insect eggs
A single larva can consume hundreds of aphids during its development, making Chrysoperla rufilabris highly effective in suppressing pest populations before they reach damaging levels.
Role as a Biological Control Agent
Chrysoperla rufilabris is commonly mass-reared and released in:
- Greenhouses
- Field crops (vegetables, cotton, corn)
- Orchards and vineyards
- Ornamental plantings and home gardens
Its advantages as a biological control agent include:
- Broad prey range
- High predation rates
- Compatibility with integrated pest management programs
- Reduced reliance on chemical insecticides
However, because adults are not predatory, maintaining flowering plants that provide nectar and pollen can enhance adult survival and reproduction in the field.