|
|
How to Manage Pests
UC Pest Management Guidelines
Tomato
Cutworms
Scientific names: Variegated cutworm: Peridroma saucia
Black cutworm: Agrotis
ipsilon
(Reviewed 1/08,
updated 1/08)
In this Guideline:
|
|
|
Cutworm larvae come in various colors and patterns, but always appear smooth skinned to the
naked eye. Most species of cutworms reach 1 to 2 inches when fully grown. They
usually curl up when disturbed. Cutworms are mainly active at night. During the
day, cutworms hide in soil, under clods, or in debris at the base of plants.
Early in the season cutworms may cause stand loss by cutting off
seedling or recently transplanted tomato plants at the soil line. Later in the
season these pests can also injure tomatoes by eating irregular holes in the surface
of fruits, and tomatoes on the ground are generally the most seriously injured.
Destroy plant residues before planting,
especially when tomatoes follow a good host crop (e.g., alfalfa or beans and
cover crops that include legumes) for the cutworms. Host plant material may
also be controlled with herbicides, but if pupae are overwintering, just
getting rid of host plants may not help much. Monitor fruit in combination with
the beet armyworms damage sample or take a separate sample of the fruit touching
the ground to detect damage are important strategies in managing these pests.
Cultural Control
Cutworm incidence is often associated with residue of host plants remaining in
the field before planting. As most cutworm species have a wide host range,
tillage at least 2 weeks before planting will help destroy plant residue that
could harbor larvae. Because cutworm damage is often localized within a field,
reseeding affected areas of a field rather than treating the whole field might
be more economical.
Organically Acceptable Methods
Cultural control is an organically acceptable management tool.
Monitoring and
Treatment Decisions
Treat only when the presence of cutworms is detected. Cutworms are usually
localized within a field, so consider marking the areas where damage is
observed and treating only those areas.
| Common name |
Amount/Acre** |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
|
| The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees. When choosing a pesticide, also consider
information relating to environmental impact.
|
| |
| A. |
CARBARYL |
| |
(Sevin) Bait 5% |
30–40 lb |
12 |
3 |
| |
COMMENTS: Ground application. Do not repeat within 3 days. |
| |
MODE OF ACTION GROUP NUMBER1: 1A |
| |
| B. |
METHOMYL* |
| |
(Lannate) 90SP |
0.5–1 lb |
48 |
1 |
| |
MODE OF ACTION GROUP NUMBER1: 1A |
| |
COMMENTS: Use only when cutworms are
detected feeding on fruit. Good coverage by ground application (preferred
application method) is necessary to reach the soil surface and lower fruit in
the plant canopy. Do not use if psyllids are in the field as carbamates tend
to promote development of their populations; also if leafminers are present, it may cause outbreaks by destroying their natural enemies. |
| |
| |
|
![[Precautions]](/IMAGES/btn-precautions_bul.gif)
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Tomato
UC ANR Publication 3470
Insects and Mites
F. G. Zalom, Entomology, UC Davis
J. T. Trumble, Entomology, UC Riverside
C. F. Fouche, UC Cooperative Extension, San Joaquin Co.
C. G. Summers, Entomology, UC Davis/Kearney Agricultural Center, Parlier
Acknowledgments for contributions to the insects and mites section:
N. C. Toscano, Entomology, UC Riverside
Top of page
|
