Page Intro: Leptomastix dactylopii is a citrus mealybug parasitoid. On this page you will find a description, life-cycle info, benefits, drawbacks, scouting info, advisories, usages, and other good stuff such as ordering.
Description
These exceptional-looking, brownish-gold/yellow 3 mm. mini-wasps are best for preventing the establishment of and maintaining populations of the citrus mealybug (Planococcus citri). If established, they can adequately protect a planting for a season or, in certain situations, much longer. They have been known to have staying power. This, of course, adds to their value as a commercial biocontrol agent.
L. dactylopii, which are shipped as pre-emerged, pre-fed adults, are the product of choice when citrus mealybugs are first seen or expected to soon be seen at a given site. [Intro]
Life-style
These parasitoids, which find their hosts with their antennae or feelers, work by laying their eggs directly into the mealybugs they’re after. They do this with great enthusiasm, too, as they are known to lay up to 100 eggs during their life. The eggs hatch and the mini-wasps’ larvae consume their hosts from within (endoparasitism), slowly weakening and then killing them. Adult parasitoids emerge from the cadavers and set out to feed, mate, and repeat the cycle.
The life-span of these parasitoids is just over three weeks in their immature stages, then continue on for almost four weeks as consenting adults. The conditions for optimum performance will be between 68-77°F with relative humidity between 20-90%. 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
These parasitoids are superb biocontrol agents with excellent searching and sustainability characteristics. They’re nearly unstoppable. For example, instead of being disabled or distracted by honeydew or mealybug excrement, they consume it. Not a pleasant thought but it’s good news for the user.
L. dactylopii are excellent preventive agents, thus offering growers a potential money-saving tool. Additionally, they can establish themselves in many situations. Once established, growers might be able to reduce the size of, or even curtail, future releases due to the presence of on-site wasps; another potential money-saver.
Lastly, these parasitoids, being shipped as adults, offer the benefit of fast oviposition or egg-laying, plus a lot of host-feeding. Yes, they do that as well. [Intro]
Drawbacks
These mini-wasps won’t overwinter outdoors in cold climates. Nevertheless, they do a good job in locations where they can establish. They are on the expensive side, but are justifiable from what we’ve come to know.
Availability is hopefully good now that they are back on the market, but in the past there have been issues. This aspect, since they are just coming back onto the market now in the mid summer of 2005, after roughly an eight year absence, remains to be seen. If the past is indicative of the future as historians tell us, occasional problems with supply should be expected (sorry to be negative). [Intro]
Scouting
Reduction of pest numbers is a sure sign of success. The scout can also usually find mealybug cadavers with an exit hole in them, too. This, of course, is a very positive sign.
Prior to emergence, the scout may find mealybugs which are translucent and can see developing a parasitoid in each. Citrus mealybugs are covered with a powdery bloom which conceals their bodies under normal circumstances. If not we could more plainly see their colored translucent bodies and the variety of hues they can show. If parasitized — and in a late enough stage of larval development — this can be enormously helpful in ensuring their activity.
Even though they’re not super-small like some of the wasps discussed on this website, seeing the adults in flight is unlikely, but they can sometimes be seen… [Intro]
Advisories
…on yellow sticky traps. This isn’t a huge problem based on what was learned when they were available before, but the potential exists. Since citrus mealybugs produce a sweet honeydew, ants may be a problem with this parasitoid. Use barrier products or boric acid products to control the ants, if they are giving your “Leptos” are hard time.
If you are using Cryptolaemus montrouzieri for the control of a citrus and long-tailed mealybug (Pseudococcus longispinus) combination, you might want to avoid using L. dactylopii. The C. montrouzieri beetles need the cottony masses of the citrus mealybugs to lay eggs and thus sustain their population. If you introduce these mini-wasps they could eliminate the citrus mealybugs, which could in turn cause a collapse of the beetles’ population. This would effectively remove the long-tailed mealybug control offered by the beetles. You’d have to then supplement the L. dactylopii with Chrysoperla spp., as they are they only other biocontrol capable of the job. [Intro]
Usages
Greenhouses, interiorscapes, botanical gardens, and arboretums, are the settings where these parasitoids are most often employed. However, in the right environment, these wasps can be used with great success outdoors. [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 L. dactylopii. [Intro]
