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Cryptolaemus
montrouzieri Mealybug
Predator PO Box 1555, Ventura, CA 93002 800-248-2847 *
805-643-5407 * fax 805-643-6267 questions
bugnet@rinconvitova.com orders
orderdesk@rinconvitova.com web www.rinconvitova.com |
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Target pests
Citrus
mealybug (Planococcus citri); other
related mealybugs
Description
‘Cryptolaemus’ is the most commonly used biological control
for mealybugs.
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Adult beetles are dark brown with orange heads and tails, 4
mm (1/6 inch) long.
·
Larvae are alligators shaped, up to 1.3 cm (1/2 inch) long,
and covered with white waxy hairs that make them resemble mealybugs.
·
The adults can fly and cover large areas to search for food.
Use in
Biological Control
·
Cryptolaemus is used to control mealybugs mainly in interior
plantscapes in Canada. They can be used outdoors, but will not survive
sub-freezing temperatures.
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They are less effective on longtailed mealybug (Pseudococcus longispinus) because this
species lacks the cottony masses Cryptolaemus requires for egg-laying.
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Optimum conditions are 28°C (82°F) with relative humidity
70-80%, but they can be used between 16-33 °C (61-91 °F). Below 9°C (48°F) they
are completely inactive, while above 33°C (61-91°F) they stop searching. They
are most active in sunlight, therefore are not as effective during dull winter
months.
·
For control of citrus mealybug, Cryptolaemus can be used
along with the parasitic wasp Leptomastix
dactylopii.
The complete life cycle takes about 31 days at 27°C (81°F)
and 45 days at 21°C (70°F).
·
Sex ratio in the population is about equal, with somewhat
fewer females than males (40% females).
·
Eggs are laid among the cottony egg masses of mealybugs;
they hatch in 5-6 days at 27°C (81°F). Females lay 5-10 eggs per day, for a
total of 400-500 eggs in their 50-day life time.
·
Larvae feed on mealybugs for 12-17 days, then pupate in
sheltered places on stems or on the greenhouse structures. A single larva can
consume 250 small mealybugs. Immature “Crypt” beetle larvae look like large
mealybugs with a similar white, waxy coating – keep an eye for them as this is
a good sign of a growing predator population.
·
Adults emerge in 7-10 days, mate and females begin laying
eggs in 5 days.
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Adults and young larvae prefer to eat mealybug eggs, but
older larvae will feed on all stages of mealybugs. If food is scarce they will
also eat soft scales and aphids.
Cryptolaemus are sold as adults and are often shipped with
shredded wood or paper to protect them en route.
Do not chill the beetles below 10°C (50°F).
Cryptolaemus
are most effective when mealybug populations are high. Repeated releases are
advisable if mealybug populations are low.
General
introduction rates
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Interior plantscapes & greenhouses – 5 beetles/infested plant, or 2-5/m² (yd²).
·
Outdoors – 1250-12,500 beetles/hectare (500-5,000/acre),
near the mealybug infestation. First releases outdoors should be in early
spring.
·
Orchards –
2,500-5,000 beetles/hectare (1,000-2,000/acre) for mature fruit trees. Repeat
as needed.
Because many
foliage plants grow very slowly, it may take 2-4 months before results of
mealybug control programs are apparent. Uninfested new growth is a sign of
control.
For Best
Results
·
Control ants! They
are most likely feeding on the honeydew and guarding the mealybug. Use barriers (i.e. Tanglefoot, Stikem),
baits and disruption of ant mounds.
·
Release in early morning or late evening, and do not wear
light colored clothing because this predator is attracted to light colors.
·
Screen vents and windows to prevent escape of Cryptolaemus.
·
To keep mealybug populations down to acceptable levels in
greenhouses, several releases of Cryptolaemus may be necessary, particularly
during winter months.
Most pesticides
are not compatible with Cryptolaemus, check before using.
Most fungicides
should be safe to use.
Spreader
stickers may be harmful to Cryptolaemus.