CHRYSOforce™ R – general predator
Green lacewings — known scientifically as the Chrysoperla rufilabris — are aggressive aphid predators that have an appetite for other soft-bodied pests as well. 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 aphids and other 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 the green lacewing, but they’re very opportunistic. The green lacewing can tackle a great number of aphid species. and, 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. The eggs of the green lacewing are 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 green lacewing adults come in a tube screened at both ends. Often-times they are already laying eggs inside their packaging.
The 2 cm. green lacewing female adults, being nomadic, actively seek out colonizations of aphids. Mated females, when they find these groupings, will lay up to 200 of their 1 mm light green eggs perched atop 1 cm long filaments, among the aphids. The eggs hatch into tan-colored, alligator-like larvae that will grow to 8 mms. They will become extremely voracious feeders that will go right to work on the aphid control — and each other. They can consume 100 aphids or more! The lifespan of these predators is roughly 30 days in their immature stages, then less than 2 months as adults. The predacious larval stage of the green lacewing lasts roughly 15–20 days. The conditions for optimum natural aphid control performance will be between 67–89°F with a relative humidity of 30% or greater. These are optimum conditions and not necessarily essential for successful implementation. Please note, however, significantly cooler or warmer temperatures and humidity fluctuations may hamper reproduction and development to a certain degree.
The biggest benefit of using green lacewings for aphid control has to be the cost. The eggs are a fairly economical method, 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 as they’re nomadic.
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 and don’t worry, it’s insignificant compared to the benefits. We have yet to hear negative comments about 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 complained to one of my interiorscaper-contractor-contact of multiple adult sightings. The problem was short-lived, though. Another drawback is that the green lacewing is difficult to scout.
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 as well as looking for the eggs as they’re usually on the top surfaces of the leaves. Decimated or sucked-dry-looking aphids are another scouting sign.
Ants, if present, should be controlled. They will eat lacewing eggs and defend aphids from predators to protect their honeydew food. The ants actually “herd” the aphids in a sense, as they tend to their needs. To control the ants use barrier products like diatomaceous earth or boric acid products to control the ants. Pollen, nectar, and even honeydew will help sustain the green lacewing adults. They are not predacious but do need food so a product such as Wheast may prove useful for green lacewing adults. It is upon this type of formula that lacewing adults are commercially reared.
The eggs and larvae are useful in greenhouses, fields, interiorscapes (though not where the public will be at night), orchards, and gardens. We’ve seen the successful aphid control 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
Release Rates for Chrysoperla rufilabris
|Prevent||2-5 per 10sq.ft. bi-weekly, 2-3 times|
|Low||1-3 per 10sq.ft., monthly, as needed|
|Med||4-8 per 10sq.ft., weekly, 2-4 times|
|High||1 per sq.ft., bi-wkly, 3-5 times|
|Maint||1-2 per 10sq.ft., tri-weekly, indef.|
|Garden||60-90% of rates listed|
|Acre+||20-50% of rates listed.|
|Comments||Rates shown are for larvae. If you’re using eggs, multiply the calculated rate by five (5). If employing adults, divide the calculated rate by four (4).|