Page Intro: Chrysoperla spp.: C. carnea and C. rufilabris — also known as green lacewings — are aggressive aphid predators that have an appetite for other soft-bodied pests as well. On this page you will find a description, life-cycle info, benefits, drawbacks, scouting info, advisories, usages, beyond the page, and other good stuff such as ordering.
Description
These nocturnal predators come in three major forms: eggs, larvae and adults. The eggs are useful when you’re in no great hurry to get rid of the pests. The larvae are useful for the quick cleanup. And the adults, being nomadic like Aphidoletes aphidimyza, are useful in tree applications. The larvae are the only predatory form of this insect. And what a form they are; very opportunistic. Like the two preceding biocontrol agents, Chrysoperla spp. can tackle a great number of aphid species. Moreover these predators may eat outside of their aphid-preference diet to enjoy other soft-bodied pests: scale insect immature stages, including long-tailed and other mealybug species, whiteflies, and others, especially certain insect eggs. [Intro]
The eggs are normally shipped loose in an inert medium of rice-hulls. The rice-hulls are a distribution carrier to facilitate the proper placement of the eggs. The larvae are very cannibalistic and must be separated in transit. This is accomplished by means of a frame or hexcell unit (though bulk-bottle forms are available which need immediate attention). The hexcell unit is comprised of little compartments which can be opened a-row-at-a-time for predator release. The adults come in a tube screened at both ends or a bag. Often-times they are already laying eggs inside their packaging. [Intro]
Life-style
The 2 cm. Chrysoperla spp. female adults, being nomadic, as mentioned above, actively seek out colonizations of aphids. Mated females, when they find these groupings, will lay their 1 mm. light green eggs which are perched atop 1 cm. long filaments, amongst the aphids — up to 200 of them. The eggs hatch into tan-colored, alligator-like larvae, which grow to 8 mm., and are extremely voracious feeders which will go right to work on the aphids — and each other. They can consume 100 aphids or more! The life-span of these predators is roughly 30 days in their immature stages, then less than 2 months as adults. The predacious larval stage lasts roughly 15-20 days. The conditions for optimum performance will be between 67-89°F with a relative humidity of 30% or greater. But these are optimum conditions and not necessarily a prerequisite of successful implementation. Please note, however, significantly cooler or warmer temperatures and humidity fluctuations may hamper reproduction and development a certain degree. [Intro]
Benefits
Cost. The eggs are a fairly economical method of application. However, with the eggs, you sacrifice some effectiveness and speed. For those traits, the larvae, or “aphid lions” as they’re sometimes called, are the way to go. The larvae are one of the fastest predators available, from release to first meal, anyway. Moreover, because of their opportunistic nature, they are useful for a few pests in addition to aphids. For reliability, though, use them for aphids and, perhaps, scale insect species. The adults are effective when treating orchards and such, even though I prefer A. aphidimyza. The adults are nomadic as explained previously. [Intro]
Drawbacks
Well, for one thing, the larvae, especially the larger ones, can deliver a painful little bite (to people and each other). This is not to scare you. It’s insignificant compared to the benefits. And only once have I had negative feedback regarding this slight drawback. Nor have I heard negative comments regarding the use of this predator in interiorscapes. Except one… The adults, nocturnal as they are, come out at night. Once, in a hospital cafeteria, the night-shift did complain to one of my interiorscaper-contractor-contact of multiple adult sightings. The problem was short-lived, though. Another drawback is that they’re difficult to scout. [Intro]
Scouting
The scout is going to be hard-pressed to find actual larvae or adults by day; they are usually well hidden. If the scout wants to locate larvae and adults, he or she should plan on doing so either in the evening or on an overcast day. Clean new growth is one sign effective as a scouting aid. Another is to look for the eggs. They are usually on the top surfaces of the leaves. Decimated or sucked-dry-looking aphids are another scouting sign. [Intro]
Advisories
Ants, if present, should be controlled. They will eat lacewing eggs and defend aphids from predators to protect their honeydew food. The ants actually sort of “herd” the aphids as they tend to their needs. Use barrier products like diatomaceous earth or boric acid products to control the ants. Pollen, nectar and even honeydew will help sustain the adults. They are not predacious but do need food. A product such as a commercial honeydew substitute may prove useful for green lacewing adults. It is upon this type of formula that lacewing adults are commercially reared. [Intro]
Usages
The eggs and larvae are useful in greenhouses, fields, interiorscapes (though not where the public will be after hours), orchards and gardens. I’ve seen the successful implementation of these species in just about every conceivable situation. The adults should be used only in row crops, trees, orchards and, possibly, tall interior plantings. The adults will lay eggs next to aphid colonies as discussed previously. Therefore, consider using another biocontrol agent like A. aphidimyza for tree pests other than aphids. [Intro]
Beyond the Page
The entomologist for the State of New Hampshire — now retired — once stated that “if lacewings were the size of dogs, all of humanity would be in trouble…” …because of the ferocity of this predator. Well, I don’t know about the humanity angle, but it should be noted that Chrysoperla spp. can have an impact on long-tailed mealybugs. Check out Scale & Mealybugs for more on this pest. [Intro]
Rates, Instructions, and Purchase
Need more information? Check out our release rates or our short-term storage, handling, and release instructions. You may also purchase Chrysoperla spp. eggs (also on cards) or purchase Chrysoperla spp. larvae (also in a bottle). [Intro]
