|
|
How to Manage Pests
UC Pest Management Guidelines
Artichoke
Artichoke Aphid
Scientific name: Capitophorous elaeagni
(Reviewed 1/07,
updated 4/08)
In this Guideline:
|
|
|
Artichoke aphids are
pale greenish white to yellowish green, almost translucent aphids with pale
appendages. The tips of the very long cornicles (siphunculi) are distinctly
dusky in color. The tubercles (located at the base of the antennae) are diverging in
contrast to those in the green peach aphid, which are converging.
Wingless adults have a long capitate hair on the third and the posterior
abdominal segments; winged adults have an almost rectangular solid black spot
on their abdomen. This aphid overwinters on its primary hosts, Elaeagnus species
(Russian olive, silverberry, and others), migrating in summer to thistles (Circium, Carduus) and to
artichokes where it can cause economic damage.
Large
numbers of these aphids cause artichoke leaves to curl and turn
yellow and the plants to show retarded growth, resulting in the formation of undersize
or deformed artichoke buds. In addition, bud stalks weaken and can no
longer support the weight of developing buds, causing them to droop.
Also, buds that are close to harvest get contaminated with aphid bodies. Besides
this direct-feeding damage, artichoke aphid characteristically secretes copious
amount of honeydew, which is deposited onto leaves and developing artichoke
buds in the lower canopy, giving them a wet and shiny appearance. Honeydew
deposits on the foliage result in the growth of sooty
mold,
which covers the leaf surface and interferes with photosynthesis. It is
estimated that 10-15% of the crop harvested during August-September is lost
because of poor quality that is a result of aphid damage. Also, aphid injury
may delay the fall harvest by several weeks because of retarded plant growth.
Artichoke
aphid is a serious problem on perennial artichokes during summer when the
average humidity and air temperature are in the high range; it is not
a problem in southern California annual artichoke fields. When choosing insecticide treatments to
control other pests, consider the impact of the materials on natural enemies of
this aphid. When conditions are ideal for development of populations, monitor the crop weekly to determine
the need to treat.
Biological
Control
Several parasitic wasps attack aphids in artichoke, most notably
species in the genera Diaeretiella and
Lysiphlebus. General predators
including lady beetles, syrphids fly, 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 parasites.
Cultural Control
Destroy crop residue immediately after harvest.
Organically
Acceptable Methods
Biological controls, cultural controls, and neem oil are acceptable for
use on organically certified crops.
Monitoring
and Management Decisions
An outbreak of artichoke aphids is most likely to occur during periods of high
average daily temperatures coupled with high relative humidity (98–100%).
These conditions generally prevail from June to September. Intensify field
monitoring during this period by making weekly observations.This aphid
remains on the underside of the older leaves when population levels are low; at
higher population levels, aphids spread rapidly throughout the plant. A population
density of an average of 3 aphids per leaflet is considered a treatment
threshold. At this population level, isolated plants will start to show the
sooty mold on the foliage. Within a few days, the infestation becomes more
conspicuous as large contiguous areas start turning black from the growth of
sooty mold.
| Common name |
Amount/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
|
| When choosing a
pesticide, consider information relating to impact on natural enemies and
honey bees and to the environment.
|
| |
| A. |
IMIDACLOPRID |
| |
(Provado) 1.6F |
4-10 oz |
12 |
7 |
| |
MODE OF ACTION: A
neonicotinoid (Group 4A)1 insecticide.
|
| |
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. |
| |
| B. |
CARBOFURAN* |
| |
(Furadan) 4F |
0.5 pt |
48 |
see comments |
| |
MODE OF ACTION: A
carbamate (Group 1A)1 insecticide.
|
| |
COMMENTS: Use allowed
under a 24(c) registration, which limits total applications of this product
to 2 per season. The preharvest
interval is 10 days for 0.5pt/acre and 21 days for 1-2 pt/acre. For artichoke aphid, do not exceed 1
application (0.5 pt or 0.25 lb a.i./acre/season). The 24(c) allows two
applications/season for cribrate weevil; however, applications for artichoke
aphid are not allowed if a second application for cribrate weevil was
made. This material also gives
good control of proba bug. If
treating for cribrate weevil, do not make a second application for cribrate
weevil if an application for proba bug, lygus bug, artichoke aphid, or other
aphids is planned. Do not apply
through any type of irrigation system.
Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. |
| |
| C. |
BIFENTHRIN* |
| |
(Brigade) WSB |
16 oz |
12 |
5 |
| |
MODE OF ACTION: A
pyrethroid (Group 3)1 insecticide.
|
| |
COMMENTS: Do not
exceed 16 oz/acre between bud formation and harvest. Do not exceed 80
oz/acre/season. Mixing bifenthrin and permethrin at their half rate gives
acceptable control at less cost; however, be sure to observe all restrictions and precautions on the labels of both products. |
| |
| D. |
PYRETHRIN/ROTENONE |
| |
(Pyrellin E.C.) |
Label rates |
12 |
0.5 |
| |
MODE OF ACTION: A
botanical (Group 3)1 insecticide and a synergist (Group 21)1.
|
| |
| E. |
NEEM OIL# |
| |
(Trilogy) |
1% solution |
4 |
0 |
| |
MODE OF ACTION: Unknown.
|
| |
COMMENTS: Thorough coverage is important; apply in a minimum of 75 gal water/acre. |
| |
| |
|
![[Precautions]](/IMAGES/btn-precautions_bul.gif)
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Artichoke
UC ANR Publication 3434
Arthropods
M. A. Bari, Artichoke Research Foundation, Salinas
W. E. Chaney, UC Cooperative Extension, Monterey County
E. T. Natwick, UC Cooperative Extension, Imperial County
Acknowledgment for contributions to the arthropod section:
W. L. Schrader, UC Cooperative Extension, San Diego County
L. Handel and T. K. Shannon, Kleen Globe, Inc., Castroville, CA
Top of page
|
