How to Manage Pests
UC Pest Management Guidelines
Floriculture and Ornamental Nurseries
Cabbage Looper
Scientific name: Trichoplusia ni
(Reviewed 3/09, updated 5/10, corrected 5/19)
In this Guideline:
Loopers arch their backs as they crawl. Cabbage loopers are light
green and usually have a narrow, white stripe along each side and several
narrow lines down the back. The dome-shaped eggs are laid singly on the
undersurfaces of older leaves. Adult moths have brown, mottled forewings marked
in the center with a small, silver figure 8.
Young cabbage looper larvae feed primarily on the underside of lower
leaves, skeletonizing them. Larger cabbage loopers chew entirely
through leaves and flowers.
Biological Control
A number of parasites,
both tachinid flies and parasitic wasps, attack lepidoptera larvae and reduce
their population growth rate. However, most of these larvae continue feeding through
to the last instar, so parasitized larvae will still damage crops. Viruses also
do not usually kill the larvae until later instars. Trichogramma spp. are commercially available egg parasites
that can be effective against cabbage looper. Applying insecticides other than Bacillus thuringiensis (Bt) products are
likely to exclude parasites because their residue are lethal to these beneficial
insects. For more information, see BIOLOGICAL
CONTROL.
Cultural Control
Because these pests feed on a large variety of plant species, keep
production areas free of weeds (e.g., mustards) that serve as hosts to cabbage
loopers. Exclusion of winged adults can be accomplished by covering openings to
the greenhouses with screens. Screens are especially important when lights are
used at night in greenhouses to control flowering because lights attract adult
moths. Individual seedling flats may also be covered with screens to exclude
adults and larvae. Row covers can be a practical measure to exclude moths in
field production as long as the mesh prevents entry of adults and the row cover
is held above the plant surface to eliminate oviposition through the fabric.
Monitoring
and Treatment Decisions
If Bt sprays are planned, use pheromone traps to determine adult flight
activity and mating. Once adults are caught in traps, it is very likely that
larvae are present and Bt should be applied as soon as possible because it is
most effective against young larvae. Use regular visual inspections of plants
to detect larvae and their damage.For
guidelines on when to treat, see ESTABLISHING TREATMENT THRESHOLDS.
Selected Materials 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.
Class |
|
Pesticide (commercial name) |
Manufacturer |
R.E.I.1 |
Mode of action2 |
Comments |
|
botanical |
A. |
pyrethrin/PBO3
(PT Pyrethrum TR)
|
Whitmire MicroGen |
12 |
3/— |
An aerosol. |
B. |
pyrethrin/rotenone
(Pyrellin EC)
|
Webb Wright |
12 |
3/21B |
|
carbamate |
A. |
carbaryl*
(various)
|
Bayer |
12 |
1A |
|
insect growth regulator |
A. |
azadirachtin
(Azatin XL)
|
OHP |
4 |
un |
Must contact insect. Repeat applications as necessary. Label permits low-volume application. |
B. |
diflubenzuron
(Adept 25WP)
|
Chemtura |
12 |
15 |
|
C. |
novaluron
(Pedestal)
|
Chemtura |
12 |
15 |
Use no more than twice per year and don't exceed 52 oz/acre/year. Don't use on poinsettia. |
D. |
tebufenozide
(Mimic, Confirm)
|
Dow Agro
Sciences
|
4 |
18 |
|
microbial |
A. |
Bacillus
thuringiensis
ssp. Kurstaki#
(various products)
|
Valent |
4 |
11 |
Most effective against early instar larvae; pheromone trapping recommended for timing applications. |
organophosphate |
A. |
acephate
(Orthene T, T&O Spray)
|
Valent |
24 |
1B |
A number of chrysanthemum varieties have
exhibited phytotoxic reactions. In greenhouse only labeled for greenhouse use
on anthurium, cacti, carnation, rose, orchids, some foliage plants, young
poinsettia, and some varieties of chrysanthemum. Can stunt new growth in roses. |
B. |
acephate
(PT 1300 Orthene TR)
|
Whitmire MicroGen |
24 |
1B |
An aerosol only for greenhouse use. |
pyrethroid |
A. |
Bifenthrin
(Attain TR)
|
Whitmire MicroGen |
12 |
3 |
Check label. A fogger for greenhouse use only. |
B. |
bifenthrin*
(Talstar Professional)
|
FMC |
12 |
3 |
Label permits low-volume application. |
C. |
cyfluthrin
(Decathlon 20WP)
|
OHP |
12 |
3 |
Label permits low-volume application. |
D. |
deltamethrin*
(DeltaGard)
|
Bayer |
12 |
3 |
|
E. |
fenpropathrin*
(Tame 2.4EC Spray)
|
Valent |
24 |
3 |
Label permits low-volume application. |
F. |
fluvalinate
(Mavrik Aquaflow)
|
Wellmark |
12 |
3 |
Label permits low-volume application. Also labeled as a cutting dip at 5 fl oz/100 gal. |
G. |
permethrin
(Astro)
|
FMC |
12 |
3 |
Direct application to blooms may cause
browning of petals. Marginal leaf burn may occur on salvia, diffenbachia, and
pteris fern. Label permits low-volume application. Do not apply more than 2 lb a.i./acre/year. |
spinosyn |
A. |
spinosad
(Conserve SC)
|
Dow Agro
Sciences
|
4 |
5 |
Do not apply more than 10 times in a
12-month period. Compatible with most beneficials, but highly toxic to bees
and hymenopteran parasites. Direct contact can cause significant mortality to
Phytoseiulus persimilis.
|
![[Precautions]](/IMAGES/btn-precautions_bul.gif)
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
Top of page
|