Citrus mealybug parasitoid
An orangish to yellow-brown wasp about 2–3 mm (1/12–1/8 inch) long that lays its eggs in citrus mealybugs. The larva eats the mealybug from inside and turns it into an oblong, crusty, barrel-shaped mummy, from which the adult cuts its way out. UC credits it with controlling citrus mealybug in greenhouses, often alongside the mealybug destroyer. It is hard to buy now. Koppert, Biobest, BioBee and Arbico do not list it, and Rincon-Vitova still has a bulletin and catalogue entry but leaves it off its regular shipping list. Learn to recognise it and protect it rather than planning to order it.
At a glance
- Kind
- Wild — rarely sold now
- Adult
- 2–3 mm, orangish to yellow-brown; males smaller
- Lays in
- Last-instar nymphs, young adult females
- Egg to adult
- About 3 weeks when warm (UC)
- Kills
- About 60–100 mealybugs per female (UC)
- Sign
- Barrel-shaped mummies with an exit hole
How it works
The female lays in third (last) instar nymphs and young adult female mealybugs. The larva, a pale maggot with one to each host, feeds inside through four instars, and the mealybug hardens into an oblong, crusty, barrel-shaped mummy. The adult leaves through a hole or a hinged cap at one end. Each female parasitises about 60–100 mealybugs in a life of several weeks. Rincon-Vitova says adults feed on mealybug honeydew or nectar and live longer when they have it.
Rincon-Vitova's bulletin gives the life cycle as about 25 days at 72 °F (22 °C) and 18 days at 80 °F (27 °C), with the first mummies showing about two weeks after a release. The bulletin says other mealybugs are not parasitised, and UC Pest Notes say it kills only citrus mealybug. UC's natural enemies gallery, however, records it from at least 50 mealybug species, including long-tailed, Comstock and grape mealybugs. In practice it is used for citrus mealybug, so expect little from it on anything else.
What it is confused with
Several small wasps work in mealybug colonies, and their mummies look much alike. The adult, or how many wasps leave one mummy, tells them apart.
- Also goodAnagyrus wasps — Also leave a crusty, puffy, orange mummy with an exit hole, so the mummies alone will not separate them. Females are smaller (1.5–2 mm) and brown with distinctive black-and-white banded antennae; males are mostly black.
- Also goodAcerophagus wasps — Several tiny wasps can come out of one mummy (UC shows five from a grape mealybug). Leptomastix raises one wasp per mealybug.
- Also goodMealybug destroyer larva — White and waxy like an oversized mealybug, but fast-moving and up to 1/2 inch long. It eats mealybugs from outside and leaves no mummies.
How to keep it around
Adults live longer with honeydew or nectar to feed on. UC's advice for keeping mealybug parasitoids working applies to this one:
- Keep ants off infested plants, because they protect mealybugs from their natural enemies
- Avoid broad-spectrum insecticides for any pest in the area
- Look for gold pupae and mummies with emergence holes before treating a colony. If you find them, the wasps are already working
- Outdoors, grow flowering plants near mealybug-prone plants so the adults have nectar
- If you do find a seller, leave 2–4 weeks between a pesticide and a release (Rincon-Vitova)
Pesticide sensitivity
Rincon-Vitova says it is susceptible to many of the pesticides mealybugs have become resistant to, and that 2–4 weeks are generally needed between a pesticide application and a release. Open the compatibility matrix →
When to choose something else
Leptomastix was the specialist partner to the mealybug destroyer on citrus mealybug. Because it is hard to buy now:
- If you need something to release, the mealybug destroyer is widely sold and works on breeding colonies of citrus mealybug
- If you want a parasitoid, Koppert sells Anagyrus vladimiri (Citripar) for citrus mealybug, and Biobest sells the same wasp for mealybugs
- If the mealybug is long-tailed, do not count on Leptomastix: Rincon-Vitova and UC Pest Notes say it attacks only citrus mealybug, although the UC gallery lists long-tailed among its hosts
Citrus mealybug parasitoid by target
What it eats and when it turns up differ by pest. Each page below is the picture for one target.