|
|
How to Manage Pests
UC Pest Management Guidelines
Apple
Rosy
Apple Aphid
Scientific name: Dysaphis
plantaginea
(Reviewed 8/06,
updated 8/06)
In this Guideline:
|
|
|
Newly hatched rosy apple aphids are dark green and are found on new
growth in early spring. Mature rosy apple aphids, clustering in curled leaves
or on young fruits in spring, are purplish and covered with a waxy, powdery
bloom. Winged forms develop on apple trees in late spring and migrate to plantain,
where they are found in summer. In fall, winged forms develop and migrate back
to the apple trees. Overwintering eggs are
laid on fruit spurs and shoots of the apple trees; they are shiny, black, and
elongated.
This is potentially the most damaging aphid species on apples. Rosy
apple aphids cluster on leaves of fruit spurs and growing shoots where they
cause severe leaf curling. Fruits on heavily
infested fruit spurs fail to properly develop and become misshapen.
Rosy apple aphid numbers vary considerably from year to year; this
aphid is not a pest every year. Like many aphids, rosy apple aphid spends part
of the growing season on alternate host plants. The most common host is
buckhorn plantain, Plantago lanceolata, also known as ribgrass. Other hosts are P.
major and P.
rugelii. Do not
allow these weeds to grow in your cover crop. These species often become a
problem when you mow rather than cultivate. Monitor for eggs during the dormant
season to determine need for treatment.
Biological Control
There are
many natural enemies that feed on rosy apple aphids; however, fruit size may be
reduced before natural enemies bring the aphids under control. Among the
important predators are lady
beetles,
green lacewings, brown lacewings, syrphid fly larvae,
and soldier beetles.
Inseason sprays (even soap sprays) applied to control rosy apple aphid can kill
natural enemies, allowing rosy apple aphid populations to increase.
Organically Acceptable Methods
Biological
control, approved narrow range oil sprays, and the use of azadirachtin (Neemix)
are organically acceptable.
Monitoring and
Treatment Decisions
During the
dormant season collect 25 to 100 fruit spurs from various parts of trees
throughout the block. Using a hand lens, examine the spurs for rosy apple aphid
eggs. This can be done in conjunction with the dormant European red mite
sample. Although difficult to detect, if any eggs are found, a dormant
treatment is required because aphid colonies may quickly spread over the tree.
Treat nonbearing trees to prevent stunting of terminal shoots. Because
overwintering eggs are located on the bark, delayed dormant application will
greatly reduce populations. Young trees need to be treated when terminals are
infested; mature trees can tolerate more damage. Codling moth sprays should be
chosen with aphid control in mind.
| Common name |
Amount to Use |
P.H.I.+ |
| (trade name) |
(conc.) |
(dilute) |
(days) |
|
| When choosing a pesticide, consider
information relating to the impact on natural
enemies and honey bees and
environmental impact.
|
| |
| DORMANT AND DELAYED DORMANT
|
| A. |
DORMANT FLOWABLE EMULSION OIL |
8 gal |
4 gal |
|
| |
MODE OF ACTION: Contact including smothering and barrier effects. |
| |
COMMENTS: Organic growers should apply
dormant flowable emulsion during delayed dormant to silver tip stage to get any control of rosy apple aphid. |
| |
| B. |
NARROW RANGE OIL |
4–6 gal |
1–1.5 gal |
|
| |
MODE OF ACTION: Contact including smothering and barrier effects. |
| |
. . . PLUS . . . |
| |
CHLORPYRIFOS* |
| |
(Lorsban) 4EC |
Label rates |
|
| |
MODE OF ACTION: An organophosphate (Group
1B)1 insecticide.
|
| |
COMMENTS: This is the best material to use
if apple pandemis is also present. Follow restrictions on supplemental label.
Avoid drift and runoff into surface waters or choose alternative materials.
Chlorpyrifos has been found in surface waters at levels that violate federal and state water quality standards. |
| |
. . . OR . . . |
| |
DIAZINON* 50WP |
4 lb |
1 lb |
|
| |
MODE OF ACTION: An organophosphate (Group
1B)1 insecticide.
|
| |
COMMENTS: Avoid drift and runoff into
surface waters or choose alternative materials. Diazinon has been found in surface waters at levels that violate federal and state water quality standards. |
| |
| SPRING FOLIAGE SPRAY
|
| A. |
IMIDACLOPRID |
| |
(Provado) 1.6F |
8 fl oz |
2 fl oz |
7 |
| |
MODE OF ACTION: A neonicotinoid (Group 4A)1
insecticide.
|
| |
COMMENTS: Apply before leaf curling starts.
Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid-Provado;
thiamethoxam –Actara) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an
insecticide that has a different mode of action Group number to help delay
the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control. |
| |
| B. |
ACETAMIPRID |
| |
(Assail) 70 WP |
1.1-1.7 oz |
— |
7 |
| |
MODE OF ACTION: A neonicotinoid (Group 4A)1
insecticide.
|
| |
COMMENTS: May cause outbreaks of mites,
especially in orchards with chronic mite problems; addition of 1% oil (volume
by volume) and limiting applications to a single application may help
mitigate mite problems. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail;
imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an
insecticide that has a different mode of action to help delay the development
of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control. |
| |
| C. |
THIACLOPRID |
| |
(Calypso) |
2-4 fl oz |
0.5-1 fl oz |
30 |
| |
MODE OF ACTION: A neonicotinoid (Group 4A)1
insecticide.
|
| |
COMMENTS: Most effective at early leafing.
May cause outbreaks of mites, especially in orchards with chronic mite
problems; addition of 1% oil (volume by volume) and limiting applications to a
single application may help mitigate mite problems. Otherwise, to help prevent the development of insect
resistance, limit applications to one generation/year. Repeat applications of
any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and
thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an
insecticide that has a different mode of action to help delay the development
of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control. |
| |
| D. |
DIAZINON* 50WP |
4 lb |
1 lb |
21 |
| |
MODE OF ACTION: An organophosphate (Group
1B)1 insecticide.
|
| |
COMMENTS: Foliage treatments are important
for young trees with severe infestations. Applications made during the foliage
season are very disruptive to beneficials. Codling moth sprays will normally
control aphids. Avoid drift and tailwater runoff into surface waters. |
| |
| E. |
NARROW RANGE OIL# |
| |
(JMS Stylet Oil, Omni, etc.) |
Label rates |
|
| |
MODE OF ACTION: Contact including smothering and barrier effects. |
| |
COMMENTS: Apply as soon as colonies are
found and reapply at 7- to 10-day intervals as long as active colonies are found. |
| |
| F. |
NARROW RANGE OIL# |
| |
(JMS Stylet Oil, Omni, etc.) |
Label rates |
|
| |
MODE OF ACTION: Contact including smothering and barrier effects. |
| |
. . . PLUS . . . |
| |
AZADIRACHTIN# |
| |
(Neemix) |
Label rates |
|
| |
MODE OF ACTION: A botanical/insect growth
regulator (Group 26)1 insecticide.
|
| |
COMMENTS: Apply as soon as colonies are
found and reapply at 7- to 10-day intervals as long as active colonies are found. Azadirachtin without oil is not effective in controlling this pest. |
| |
| |
|
![[Precautions]](/IMAGES/btn-precautions_bul.gif)
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Apple
UC ANR Publication 3432
Insects and Mites
J. L. Caprile, UC Cooperative Extension, Contra Costa County
L. R. Wunderlich, UC Cooperative Extension, El Dorado County
P. M. Vossen, UC Cooperative Extension, Sonoma and Marin counties
W. W. Coates, UC Cooperative Extension, San Benito County
H. L. Andris, UC Cooperative Extension, Fresno County
L. G. Varela, UC IPM Program, Sonoma County
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
Acknowledgment for contributions to the insects and mites section:
C. Pickel, UC IPM Program, Sutter and Yuba counties
Top of page
|
