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Aphytis
melinus
The Golden Chalcid
Armored Scale
Parasite PO
Box 1555, Ventura, CA 93002 800-248-2847 *
805-643-5407 * fax 805-643-6267 questions bugnet@rinconvitova.com orders orderdesk@rinconvitova.com www.rinconvitova.com |
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Contents 5k, 10k, 20k or 30k adults for immediate release. Check contents
and report any problems at time of delivery.
Target pests (in order of preference)
California red scale, Aonidiella
aurantii, on citrus, roses and ornamentals
Ivy or oleander scale, Aspidiotus
nerii, on a wide range of hosts including palm and cycads
San Jose scale, Quadraspidiotus
perniciosus, and Walnut scale, Q.
juglanregiae
Dyctyospermum scale, Chrysomphalus
dictyospermi, on a wide range of hosts
Biology
Aphytis melinus is a small (1 mm) yellow wasp that
parasitizes various types of armoured scales by laying eggs under the waxy
scale covering. Parasite larvae develop under the scale covering. Only 2nd
and 3rd instar of female scales and 2nd instar and
pre-pupae male scales are parasitized. Many other stages of scales are killed
by adults host feeding on them. Parasitized scales look dried out and may have
dark spots when examined closely. Rubbing infested fruit and noting the amount
of dead scales removed can give a quick assessment of parasitism. Scale with
young parasites and no parasites will stay on the fruit. At 80° F, A. melinus takes 13-17 days to develop
from egg to adult. Adults live about 10-15 days (up to 24 days), depositing 6-7
eggs/day. Optimal release conditions are between 60-85° F, at least
50% RH and in areas with scales of suitable stages for parasitism. Minimum
temperature for release is 40° night and 60° day. They
start flying at 50° and you need several hours above that
for them do lay eggs.
Aphytis melinus are available in plastic cups of
5,000-30,000. In general they should be released regularly (1-3 week intervals)
at the first sign of scale in the spring until low scale populations are
maintained.
¨ To build an established population in
orchards, 1-2 cups/acre should be released every other week until the scale
population is reduced to a low level. Release on the shaded side of the trees
at temperatures below 90° F. Release some parasites every sixth
tree every sixth row starting at a different row each week to assure even
distribution (~175/tree). The parasites can be released either by leaving an
opened cup in a tree infested with scales or by walking though the orchard with
an opened cup for more rapid dispersal. Afterwards an annual release of ½ -1
cup/acre is recommended in the spring. Use a summer oil spray to reduce high
number of scales 2-3 weeks before releasing parasites.
¨ For interior plantings, regular
releases of A. melinus work best and
can control infestations in 2-3 months. Afterwards 1-3 releases/year should be
sufficient to maintain control. The release rate depends on the suitability of
the scale host. A guideline rate is 5-10 parasitoids/ infested plant or 10/sq
yard. Release parasites by waving an opened cup around infested plants 2-3
times at 2-3 week intervals. Release at dusk or with the windows shaded so the
Aphytis will find infested plants quicker. If initial scale populations are
high, apply insecticidal soap 2-3 weeks before 1st release. Wash off
honeydew accumulations off plants just before release.
Use parasites same day of arrival. If necessary to hold,
keep cool (approx. 60° F) and dark until use. Do not
refrigerate or place insects directly next to cold packs. Viability decreases
rapidly with prolonged storage.
Pesticide
compatibility
Oil sprays, insecticidal soaps, Bacillus thuringiensis and Sabadilla. If more toxic pesticides must
be used, Aphytis should be released again about 4 weeks after application.