Green lacewing

Chrysoperla rufilabris

In addition to the parasitic wasps, several predators are also available for aphid management, including three life stages of the lacewing Chrysoperla rufllabris. Adults of this species are approximately 2 cm in length, bright green in colour, and with delicate, transparent wings with many fine veins. Chrysoperla adults feed on aphid honeydew, nectar and pollen, and lay their eggs on leaves or stems close to aphid colonies. Each egg is supported on a thin ‘stalk’ (approximately 4-5 mm long), and is initially bright green, gradually becoming darker as the larva develops within. 

Lacewing larvae have pronounced curving mandibles which are used to impale their prey and suck out the internal fluids. All three larval stages are predaceous and will feed on a variety of soft-bodied arthropods, including aphids, mites, immature whiteflies, some insect eggs and the smaller larvae of several moth and beetle species. Approximately 70-80% of the total lifetime prey consumption occurs when the insect is in its third (final) larval stage, and each larva may consume approximately 150 final instar aphids during its development. Mature larvae are about 6-7 mm long and pupation takes place within a white oval silken cocoon that is constructed in sheltered sites on the plant, under plant-pot rims, etc.

The optimal temperature for this species is approximately 25°C (77°F), with a relative humidity of 7S% or higher_ Survival and reproduction are reduced at Iower relative
humidities (55% or less), and by temperatures below 20°C (68°F). At 25°C and 75% relative humidity, the life-cycle (egg to adult) is completed in approximately 20-25 days. Under such conditions, adults may live for 4 weeks or more and lay approximately 250 eggs.

Chrysopeda rufilabris is available as eggs, larvae or adults. In choosing between life stages, keep in mind that, while the larvae are good for addressing aphid ‘hot spots’, their Iack of wings limits their dispersal ability and hence they must be released close to prey patches. Adults are better able to locate prey colonies in which to lay their eggs, but pest populations will not be impacted until the eggs hatch and the lacewing larvae start to feed.