Lettuce XXVII-3

Loopers

Whitney S. Cranshaw

Cabbage Looper

Identification (and life cycle/seasonal history)

Cabbage looper, celery looper and other species can feed on lettuce. Adult moths emerge and mate in late spring, soon after laying eggs on plant leaves. Early instars feed on outer leaves, but then move toward the head as they grow. Two or three generations may be produced during the growing season.

Plant Response and Damage.

Defoliation is generally not sufficient to cause plant stress. However, the marketed head can be damaged by late instar loopers burrowing. Populations of loopers generally are highest late in the season.

Management approaches

Cultural Controls

Row covers are effective in excluding loopers and preventing egg laying.

Biological Control

Loopers are preyed upon by several generalist predators, such as wasps and spider. Parasites and viral diseases also commonly kill loopers. Bacillus thuringiensis is effective in killing larval stages.

Chemical control

Since damage is caused by large larva feeding and burrowing into the head, control should be employed when larvae are small and exposed on the wrapper leaves.

 

 

Product List for Loopers:

 

Insecticide

Product per Acre

Preharvest Interval, remarks

 

Dipel 2X, Biobit W

Dipel 4L, Biobit F

Javelin WG

0.5-2.0 lb

0.5-2 pt

0.25-1.0 lb

(0 days) Bacillus thuringiensisis under current regulations for activity. Labeled for application through sprinkler systems. Certified Organic produce. Stomach poison product. Most formulations are acceptable.

 

Ambush 25WR, Pounce 25WR

Pounce 3.2ER

Ambush 2ER

6.4-12.8 fl oz

4-8 fl oz

6.4-12.8 oz

(1 day)

Pounce and Ambush are pyrethroid insecticides (permethrin).

Extremely toxic to fish and other
aquatic organisms.

 

Ammo 2.5ER

Cymbush 3ER

1.28-5.0 fl oz

1.1-4.5 fl oz

(5 days) Labeled for chemigation. Cymbush and Ammo are pyretlrroid insecticides (cypermethrin). Highly toxic to aquatic organisms.

 

Lannate 90SR

Lannate LR

0.25-1 lb

1-4pt

(7-10 days)

Carbamate insecticide (methomyl).  48 hour reentry interval proposed. Not registered for chemigation.

 

Thiodan 50W

Thiodan 3E, Endocide 3E

1.5-2 lb

1-1.3 qt

(14 days) Remove wrapper leaves  at harvest. 48 hour reentry proposed. Some rotational restrictions with certain root crops. Chlorinated hydrocarbon.

 

Orthene 75S

0.7-1.3 lb

(21 days) Organophosphate insecticide (acephate). Has systemic activity. Do not feed trimmings to livestock.

 

Ammo WSBR1

Ammo 2.5ECR1

1-2 bags/acre (WSB)

3.75-5.0 fl oz (2.5EC)

5 days.  Pyrethroid insecticide.  Maximum 0.6 lb (AI)/acre per season.  Registered for head lettuce only.

 

Asana XLR1

 

Kryocide 96W

 

Larvine 3.21

 

4.8-9.6 fl oz

 

8-20

 

16-30 fl oz

 

7 days. Registered for head lettuce only.  Pyrethroid insecticede.  Maximum 0.35 lb ai/A may be applied in season.

14 days.  Inorganic insecticide (sodium aluminoflouride) with stomach poison activity.

14 days.  Carbamate insecticide.  Do not exceed 1.5 lb (AI)/acre per season.  Registered for head and leaf lettuce, along with other leafy vegetables.  Has some ovicidal activity.

 

 

Mustang 1.5EWR1

 

WarriorR1

2.39-4.26 fl oz

 

1.92-3.84 fl oz

5 days.  Pyrethroid insecticide.  Maximum 0.3 lb (AI)/acre per season.  Head lettuce only.

1 day.  Pyrethroid insecticide.  Maximum 0.3 lb (AI)/acre per season.  Head lettuce only.

 

RRestricted Use Product.  1 Labeled for chemigation.
The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies.  State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

 

 Categories: Lettuce, Insects, Loopers

Date: 05/05/02