Field Crops
ALFALFA INSECT CONTROL RECOMMENDATIONS
Christian H. Krupke and John L. Obermeyer, Extension Entomologists
If you want to view as pdf, click here
Read and follow ALL label rate, application, and use directions
| This publication is intended to aid pest managers in treating pest infestations in alfalfa during the growing. |
|---|
| Pest | Active Ingredient(s) | Trade Name(s) | Pre-Harvest Interval (days) | MoA1 | Treatment Guideline |
|---|---|---|---|---|---|
| Alfalfa Weevil Larva | alpha-cypermethrin* | Fastac | 3 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | beta-cyfluthrin* | Baythroid | 7 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | cyfluthrin* | Tombstone | 7 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | indoxacarb | Steward | 7 | 22 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | permethrin* | Pounce, generics | 14 | 3A | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Refer to Table 1 for management guidelines. |
| Alfalfa Weevil Larva | Pre-Mixes | Refer to Table 1 for management guidelines. | |||
| Alfalfa Weevil Larva | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Refer to Table 1 for management guidelines. |
| Aphids | afidopyropen | Sefina, Inscalis | 0 | 9D | Treatment may be advisable if: 1) the aphid population is heavy 2) less than 10% of the aphids are parasitized 3) few aphid predators are present, and 4) the average stem length is less than 14 inches. |
| Aphids | dimethoate | Dimethoate, Dimate | 10 | 1B | Treatment may be advisable if: 1) the aphid population is heavy 2) less than 10% of teh aphids are parasitized, 3) few aphid predators are present, and 4) the average stem length is less than 14 inches. |
| Aphids | Pre-Mixes | Treatment may be advisable if: 1) the aphid population is heavy 2) less than 10% of teh aphids are parasitized, 3) few aphid predators are present, and 4) the average stem length is less than 14 inches. |
|||
| Aphids | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Treatment may be advisable if: 1) the aphid population is heavy 2) less than 10% of teh aphids are parasitized, 3) few aphid predators are present, and 4) the average stem length is less than 14 inches. |
| Blister Beetles | carbaryl | Sevin, generics | 7 | 1A | Livestock ingesting hay infested with dead blister beetles may become sick or die. Controls should be applied well before harvest, and hay conditioners should not be used. Do NOT feed infested hay, even if treated, to horses. |
| Blister Beetles | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Livestock ingesting hay infested with dead blister beetles may become sick or die. Controls should be applied well before harvest, and hay conditioners should not be used. Do NOT feed infested hay, even if treated, to horses. |
| Blister Beetles | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Livestock ingesting hay infested with dead blister beetles may become sick or die. Controls should be applied well before harvest, and hay conditioners should not be used. Do NOT feed infested hay, even if treated, to horses. |
| Blister Beetles | Pre-Mixes | Livestock ingesting hay infested with dead blister beetles may become sick or die. Controls should be applied well before harvest, and hay conditioners should not be used. Do NOT feed infested hay, even if treated, to horses. | |||
| Blister Beetles | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Livestock ingesting hay infested with dead blister beetles may become sick or die. Controls should be applied well before harvest, and hay conditioners should not be used. Do NOT feed infested hay, even if treated, to horses. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | alpha-cypermethrin* | Fastac | 3 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | Bacillus thuringiensis | Dipel, Javelin, generics | 0 | 11A | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | beta-cyfluthrin* | Baythroid | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | carbaryl | Sevin, generics | 7 | 1A | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | cyfluthrin* | Tombstone | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | flubendiamide | Belt | 0 | 28 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | indoxacarb | Steward | 7 | 22 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | methoxyfenozide | Intrepid | 7 | 18 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | permethrin* | Pounce, generics | 14 | 3A | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | Pre-Mixes | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. | |||
| Caterpillars: (alfalfa caterpllar, armyworms, cutworms, green cloverworm loopers, and webworms) | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economic. Fall seedings especially need protection from larval defoliation and possibly plant death. |
| Grasshoppers | alpha-cypermethrin* | Fastac | 3 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | beta-cyfluthrin* | Baythroid | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | cyfluthrin* | Tombstone | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Grasshoppers | Pre-Mixes | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. | |||
| Grasshoppers | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Depending on the value of the crop, defoliation levels as low as 10-15% may be economically justified. |
| Lygus, Plant Bugs | alpha-cypermethrin* | Fastac | 3 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | beta-cyfluthrin* | Baythroid | 7 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | carbaryl | Sevin, generics | 7 | 1A | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | cyfluthrin* | Tombstone | 7 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | dimethoate | Dimethoate, Dimate | 10 | 1B | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | indoxacarb | Steward | 7 | 22 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | permethrin* | Pounce, generics | 14 | 3A | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Lygus, Plant Bugs | Pre-Mixes | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. | |||
| Lygus, Plant Bugs | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Alfalfa grown for seed may need protection. If there is an average of 3 adults and/or nymphs per sweep on 3-inch seed alfalfa or more than 5 adults and/or nymphs per sweep on seed alfalfa over 3 inches tall, a treatment may be advisable. |
| Meadow Spittlebug | alpha-cypermethrin* | Fastac | 3 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | beta-cyfluthrin* | Baythroid | 7 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | cyfluthrin* | Tombstone | 7 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | permethrin* | Ambush, Pounce, generics | 14 | 3A | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Meadow Spittlebug | Pre-Mixes | Treatment may be economically justified when spittle masses average more than one per stem. | |||
| Meadow Spittlebug | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Treatment may be economically justified when spittle masses average more than one per stem. |
| Potato Leafhopper | afidopyropen | Sefina, Inscalis | 0 | 9D | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | alpha-cypermethrin* | Fastac | 3 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | beta-cyfluthrin* | Baythroid | 7 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | cyfluthrin* | Tombstone | 7 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | dimethoate | Dimethoate, Dimate | 10 | 1B | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | gamma-cyhalothrin* | Declare, Proaxis | 7 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | indoxacarb | Steward | 7 | 22 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | lambda-cyhalothrin* | Warrior II, generics | 7 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | permethrin* | Pounce, generics | 14 | 3A | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | zeta-cypermethrin* | Mustang Max, Respect | 3 | 3 | Refer to Figure 1 for management guidelines. |
| Potato Leafhopper | Pre-Mixes | Refer to Figure 1 for management guidelines. | |||
| Potato Leafhopper | chlorantraniliprole; lambda-cyhalothrin* | Besiege | 7 | 28;3 | Refer to Figure 1 for management guidelines. |
| * Restricted Use Product. 1Mode of Action: Insecticides are classified based on their target site. Using different, and combined, modes of action may delay insect resistance to insecticide groups. More specific information can be found at IRAC: http://www.irac-online.org. |
|||||
| Table 1. Management Guidelines for Alfalfa Weevil Larvae |
|---|
| Use the following charts for southern and northern Indiana to determine if control is warranted. |
| Southern Indiana |
| Heat Units (Base 48°F) | % Tip Feeding 1 | Advisory |
|---|---|---|
| 200 | - | Begin sampling. South facing sandy soils should be monitored earlier |
| 300 | 0-50 | Reevaluate in 7 to 10 days using the appropriate HU, or treat immediately with a residual insecticide if 3 or more larvae are noted per stem and % tip feeding is above 50% |
| 400 | 50 | Treat immediately with a residual insecticide. |
| 500 | 75 | Treat immediately. |
| 600 | 75+ | If cutting delayed more than 5 days, treat immediately. |
| 750 | If harvested or harvesting shortly, return to the field in 4 to 5 days after cutting and spray 1) if there is no regrowth and weevil larvae are present or 2) if feeding damage is apparent on 50% of the stubble and weevil larvae are present. | |
| 1Note whether larvae are still present, actively feeding, and/or diseased. | ||
| Northern Indiana | ||
| Heat Units (Base 48°F) | % Tip Feeding 1 | Advisory |
|---|---|---|
| 250 | - | Begin sampling. South facing sandy soils should be monitored earlier |
| 300 | 0-40 (30)* | Reevaluate in 7 to 10 days using the appropriate HU, or treat immediately with a residual insecticide if 3 or more larvae are noted per stem and % tip feeding is above 50% |
| 400 | 60 (50)* | Treat immediately with a residual insecticide. |
| 500 | 75 | Treat immediately. |
| 600 | 75+ | If cutting delayed more than 5 days, treat immediately. |
| 750 | If harvested or harvesting shortly, return to the field in 4 to 5 days after cutting and spray 1) if there is no regrowth and weevil larvae are present or 2) if feeding damage is apparent on 50% of the stubble and weevil larvae are present. | |
| * Shorter than normal growth at beginning of season. 1Note whether larvae are still present, actively feeding, and/or diseased. |
||
Figure 1. Management Guideline for Potato Leafhopper (adults and nymphs)
To determine potato leafhopper numbers, take at least five sets of 20 sweeps with a 15” diameter insect sweep net, each set from a different area of the field. The sweeps should be made as you walk through an area by moving the net from side to side in a sweeping motion through the foliage. After 20 sweeps have been made, quickly gather the net together in the center. Inspect the upper portion of the inside of the net for potato leafhoppers. Then slowly open the net and let the trapped insects crawl out. Count the number of potato leafhoppers, both adults and nymphs. After taking each set of sweeps, measure the height of at least 2 stems in each area.
After all sweeps and height measurements have been taken, determine the number of potato leafhoppers per sweep and the average stem height for the field. See below the number of potato leafhoppers, required per sweep at different plant heights, before treatment is needed.
Figure 1.
Fields should be evaluated for potato leafhopper 4-5 days after harvest, when alfalfa is 3-4 inches tall. If spray is required, maximum benefit from leafhopper control can be achieved at this time. Sweep at mid day when field is dry and air temperature is highest.
READ AND FOLLOW ALL LABEL INSTRUCTIONS. THIS INCLUDES DIRECTIONS FOR USE, PRECAUTIONARY STATEMENTS (HAZARDS TO HUMANS, DOMESTIC ANIMALS, AND ENDANGERED SPECIES), ENVIRONMENTAL HAZARDS, RATES OF APPLICATION, NUMBER OF APPLICATIONS, REENTRY INTERVALS, HARVEST RESTRICTIONS, STORAGE AND DISPOSAL, AND ANY SPECIFIC WARNINGS AND/OR PRECAUTIONS FOR SAFE HANDLING OF THE PESTICIDE.
May 2023
It is the policy of the Purdue University Cooperative Extension Service that all persons have equal opportunity and access to its educational programs, services, activities, and facilities without regard to race, religion, color, sex, age, national origin or ancestry, marital status, parental status, sexual orientation, disability or status as a veteran. Purdue University is an Affirmative Action institution. This material may be available in alternative formats.
This work is supported in part by Extension Implementation Grant 2021-70006-35390/ IND90001518G-1027053 from the USDA National Institute of Food and Agriculture.
1-888-EXT-INFO
www.extension.purdue.edu
Order or download materials from www.the-education-store.com
