How to Manage Pests
UC Pest Management Guidelines
Floriculture and Ornamental Nurseries
Thread-footed (Tarsonemid) Mites
Cyclamen mite: Phytonemus
Broad mite: Polyphagotarsonemus latus
Bulb scale mite: Stenotarsonemus laticeps
In this Guideline:
Thread-footed mites are tiny and cannot be readily seen without
magnification (20X to 40X). The life stages of these thread-footed mites are:
egg, nymph, pseudopupa, and adult (one less stage than for spider mites). Eggs
of the cyclamen mite are one-half the length of the adult and are oval shaped.
Eggs of the closely related broad mite are distinguishable from cyclamen mite
eggs by rows of white pegs on the egg's upper surface. Immature stages of these
mites are white.
These mites get the name "thread-footed" from the
appearance of the hind pair of legs in the adult female, which is threadlike;
adult males, on the other hand, have stout legs for clasping the female. Adult
males carry female pseudopupae on their back. As soon as the adult female
emerges, they mate.
Cyclamen mite is generally found feeding on growing
terminals, in buds, or on unfolding leaflets. Their development is optimal
under moderately warm (60° to 80°F) temperatures and high humidity (80 to 90%).
Broad mite is similar to cyclamen mite, but is generally found mostly on the
undersides of plant leaves. Mites disperse between plants on air currents and
by mechanical transport such as on worker's clothing. These mites can complete
one generation in 7 to 21 days, depending on temperature. Female bulb scale
mites lay up to 28 eggs. Adults are usually found between the scales of the
bulb and the neck region. Bulb mites overwinter in bulbs between the scales,
emerging as the leaves grow. They re-enter bulbs as the bulbs dry in the field.
One generation can be completed in about 7 weeks under field conditions.
Feeding by cyclamen and broad mites is easily recognized on all
hosts because affected leaves become characteristically cupped, dwarfed and
thickened, and the internodes are greatly shortened. Broad mite damage occurs
more generally over the plant than cyclamen mite damage. Bulb scale mites
feeding in developing shoots can cause longitudinal bronze streaks of
discoloration, horizontal cracks, distortion, and death of leaves and flowers.
Neoseiulus californicus and
other species of predatory
have been used for broad mite and cyclamen mite control. For more information,
Because these mites feed on a large variety of plant species, keep
production areas free of weeds that can serve as hosts for mite populations.
Carefully inspect plants being brought in to start a new crop to ensure that
they are free of pests, and disinfest the plants if needed. Disinfestation can
be accomplished by immersing propagation stock in 110.3°F water for 30 minutes,
or treatment at 100% relative humidity and 110.3°F for 1 hour. If hot spots of
these mites are found in production areas, consider roguing affected plants and
treating the surrounding plants.
Monitoring and Treatment Decisions
Visually inspect plants for typical damage symptoms as part of a weekly
Registered for Use on Greenhouse or Nursery Ornamentals
Read and follow the instructions on the label before using any pesticide.
Before using a pesticide for the first time or on a new crop or cultivar, treat
a few plants and check for phytotoxicity. Also consider pesticide resistance
management and environmental impact.
||Mode of action2
||Label permits low-volume application.
hydrophobic extract of neem oil#
not spray plants under stress. Target pest must be completely covered with
spray. Check label for list of plants that can be treated. May cause injury to flowers.
(JMS Stylet Oil)
as above for neem oil. Also, do not use with sulfur fungicides; check label for tank mix restrictions.
local water/runoff restrictions. Some varieties of chrysanthemum exhibit phytotoxicity. Do not apply more than 3 lb a.i./ acre/season.
at least 2 different chemicals between applications of Sanmite. Do not use
fertilizers containing boron or apply through any type of irrigation system. Do not exceed 10.67 oz/acre/application.
contact insect, so thorough coverage is important. Repeat weekly as needed up
to 3 times. Test for phytotoxicity. Do not spray new transplants or newly rooted cuttings. Do not add adjuvants.
UC IPM Pest Management Guidelines: Floriculture and Ornamental Nurseries
UC ANR Publication 3392
Insects and Mites
J. A. Bethke, Entomology, UC Riverside
Acknowledgment for contributions to Insects and Mites:
K. L. Robb, UC Cooperative Extension, San Diego County
H. S. Costa, Entomology, UC Riverside
R. S. Cowles, Connecticut Agricultural Experiment Station, Windsor, CT
M. P. Parrella, Entomology, UC Davis
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