How to Manage Pests
UC Pest Management Guidelines
Green peach aphid: Myzus persicae
Black bean aphid: Aphis fabae
Pea aphid: Acyrtosiphon pisum
In this Guideline:
Several species of aphids may be found on artichoke plants. These
aphid species vary in color (from light green to black), size, and shape. All
are soft-bodied insects. The most important aphid pest is the artichoke aphid,
which is covered separately. Other aphids that may occur include green peach aphid,
black bean aphid,
aphid. They form dense colonies on the undersides of
artichoke leaflets and in some cases on the artichoke petioles. Winged aphids form under specific conditions of overcrowding or plant stress and disperse to
other plants or fields.
The green peach aphid occurs sporadically throughout the year.
Populations start on lower leaves. In heavy infestations, they may be found
throughout the plant. On the central coast, populations peak in spring and fall
and decline in summer and winter. Spring populations generally build up on weed
hosts occurring in the field and in uncultivated areas around the fields and
move to artichokes during March and April. In the southern coastal areas,
populations generally peak in September to November and again in March to
April. In the southern desert area where artichokes are planted as an annual
crop in August, green peach aphids attain peak densities in January and
February when the crop is ready for harvest.
Occasionally pea aphid and black
bean aphid infest artichokes that are located close to other row crops.
Unlike artichoke aphid, green peach aphid does not lower yields or
turn leaves yellow. Damage is more cosmetic in nature when green peach aphid
move into artichoke buds, contaminating the outer bracts. At low to moderate
infestation levels, these aphids can be removed by washing the produce with
water before packing. However, as the growers move towards field packing, these
low infestations may become more economically significant.
Occasionally black bean aphid populations move into developing
floral heads, which can require the heads to be culled. Also, the aphids
produce honeydew, upon which black sooty mold grows and contaminates the artichokes.
Normally these aphids do not warrant control unless contamination
is a concern.
Several parasitic wasps
attack aphids in artichoke, most notably
species in the genera Diaeretiella and Lysiphlebus. General predators including lady beetles, syrphids, and lacewings also consume aphids.
In addition, a portion of the population may be killed by a fungal disease caused by Entomophthora aphidis.
However, naturally occurring predators, parasites, and pathogenic fungi rarely
provide timely control because of considerable time lag between the buildup of
the parasite/predator populations and the aphid populations. Preserve
populations of beneficial insects by avoiding unnecessary insecticide
applications and by providing acceptable habitat for these predators and
On artichokes grown in isolated
small areas in the southern deserts where insecticide use is minimum (0-3
applications per year), growers have released convergent lady beetles for aphid
control with some success.
Destroy crop residue immediately after harvest. Avoid other
aphid-favored crops, such as lettuce, in adjacent upwind fields.
Organically Acceptable Methods
Biological controls, cultural controls,
and sprays of neem oil are acceptable for use on organically certified crops.
Monitoring and Management Decisions
Outbreaks of green peach aphid are more
likely to occur during summer and fall.Intensify field monitoring for aphids when adjacent fields with
aphid-favored crops are harvested. Inspect the bottom side of leaves and behind
lower bracts of developing artichoke buds for aphids on a weekly basis. Treat
if significant populations of aphids are present on artichoke buds. Aphids may
be a problem in only one part of a field. Check the entire field carefully to
see if spot treatments of small portions of fields may be sufficient to control
the aphid problem.
Black bean aphid is usually not
abundant enough to warrant treatment. If heavy populations occur in leaves,
treat before they move into the floral buds.
|When choosing a pesticide, consider information relating
on natural enemies and honey bees and to the environment. Not all registered pesticides are listed. Always read label of product being used.
||MODE OF ACTION GROUP NUMBER1: 4A
||COMMENTS: Do not apply more than 40 oz/acre/crop season. Do
not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area.
||MODE OF ACTION GROUP NUMBER1: 3/21
||MODE OF ACTION: Unknown. A botanical insecticide.
||COMMENTS: Thorough coverage is important; apply in a minimum of 75 gal water/acre.
||(Brigade) 2 EC
||6.4 fl oz
||MODE OF ACTION GROUP NUMBER1: 3
||COMMENTS: Do not exceed 16 oz/acre between bud formation and harvest. Do not exceed 80 oz/acre/season.
UC IPM Pest Management Guidelines: Artichoke
UC ANR Publication 3434
M. A. Bari, Artichoke Research Foundation, Salinas
E. T. Natwick, UC Cooperative Extension, Imperial County
Acknowledgment for contributions to Arthropods:
W. E. Chaney, UC Cooperative Extension, Monterey County
W. L. Schrader, UC Cooperative Extension, San Diego County
L. Handel and T. K. Shannon, Kleen Globe, Inc., Castroville, CA
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