Insect Control

Aphids, Potato (Macrosiphum euphorbiae), Green Peach (Myzus persicae), and others 

Green peach aphids (GPA) and potato aphids (PA) are the most common colonizing aphids in potato, while buckthorn (Aphis nasturtii), melon aphid (Aphis gossypii) and foxglove aphid (Aulacorthum solani) are occasional or localized pests. There are other species of aphids that do not colonize potatoes but may transmit virus as they probe potatoes in search of a host plant. 

Aphids vector potato leafroll virus (PLRV) in a persistent manner and PVY in a non-persistent manner. PLRV and some strains of PVY are capable of causing internal discoloration of tubers, and some strains of PVY can cause both internal and external defects on tubers of some varieties. Viruses reduce yield and quality in both seed and tablestock potatoes, and tolerance for virus is especially low in seed potato. GPA is the primary vector of PLRV and an efficient vector of PVY. Potato, buckthorn, and many non-colonizing aphids are also vectors of PVY. Buckthorn aphids are the smallest of potato-infesting aphids and are more common in northern Maine, where high populations can occur quite early in the season. See green peach aphid in the insect control section of Pepper and melon aphid in the insect control section of Cucumber for more information on these pests.

Potato aphid (PA) is the largest of the colonizing aphids, 3-4 mm long, elongated in shape, and may be pink or green. Its antennae are as long as the body, its cornicles are long with dark tips, and on the head between the antennae the tubercles turn outward. When disturbed, PA may drop off the plant. There are both winged and wingless forms of adult females who produce live nymphs without mating, about 50 nymphs/2 weeks. Nymphs are yellowish green or yellowish pink and become reproductive in 2 weeks. PA overwinters as eggs on plants in the rose family, feeds for several generations after hatching in spring, and colonizes a wide range of weeds, field crops, flowers, and vegetables from June through September. Vegetable crops most affected are potato, field and greenhouse tomato, lettuce, and spinach. PA feeds and builds up on young and growing plants, moving to new hosts as food quality declines. In fall they return to rose, male and female forms mate, and eggs are laid. As far north as Virginia, overwintering occurs on crops such as kale and spinach, without an egg stage; in New England, winter greens in tunnels may provide a suitable habitat bridge for PA from one season to the next.

PA feed first in young growing tips, spreading downward as they multiply. (By contrast, GPA feeds in lower leaves). Leaves become distorted, with the leaf edges curling downward, and dieback occurs from the tip downward. Potato plants may be killed at high numbers. Tomatoes show similar leaf symptoms, but blossoms are preferred, and PA colonies cause blossom drop and fruit deformities. See aphids in the insect control section of Greenhouse Tomato for more on biocontrol of PA.

Use disease-free certified seed to reduce the incidence of virus. Plant varieties that are less susceptible to viruses (See Varieties). As with other aphids, naturally occurring predators and parasitoids suppress aphid populations in the field. Use selective or systemic insecticides for Colorado potato beetle to conserve natural enemies of aphids. Spread of PLRV can be prevented when effective foliar sprays are used at threshold. However, insecticides (both systemic and foliar) offer little or no protection against PVY. Oil sprays have been shown to provide some protection from PVY transmission of non-persistent viruses, but must be reapplied regularly.

Fields should be scouted for aphids starting at 50% plant emergence in seed-producing areas, and starting in June where only fresh market or processing crops are grown. To scout, count all aphids on 25-50 fully expanded compound leaves (e.g., 5 per site, 10 sites across the field). The threshold for insecticide application depends on growth stage and the target market. Thresholds in fresh market and processing potato: before tuber initiation, average 2 aphids/leaf; tuber initiation to 2 weeks before vine kill, average 4 aphids per leaf; and within two weeks of vine kill, average 10 aphids per leaf. Because of the importance of seed production in Maine, the economic threshold for all types of potatoes is lower: when aphids are found on 50% of the plants or 1 winged green peach aphid is found within the field. Because aphids tend to infest the underside of leaves, good spray coverage is needed for foliar sprays.

IRAC Group 1:

• dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A; PHI 0d, REI 48h, Bee: H, Group 1B.
• malathion (Malathion 57EC): 1 to 1.5 pt/A; PHI 0d, REI 12h, Bee: H, Group 1B.
• methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 6d, REI 48h, Bee: H, Group 1A.
• oxamyl (Vydate* C-LV): 17 to 34 oz/A; PHI 7d, REI 48h, Bee: H, Group 1A. At-planting treatments of systemic aphicides followed by mid-season Vydate application, before previous treatment starts to break down, has provided best season-long control. Vydate* L is NOT labeled for potatoes. 
• phorate (Thimet* 20G): 8.5 to 11.3 oz/1000 row ft for light or sandy soils at planting or post-emergence, 13 to 17.3 oz/1000 row ft in heavy or clay soils at planting; PHI 90d, REI 48h, Bee: H, Group 1B. May be applied at planting in sandy or clay soils. Granules must be incorporated into the soil. May be applied post-emergence on sandy soils only. 

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H. See resistance statement on label. Aphid control may be variable depending on species present and host-plant relationships. Aids in control. 
• esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H. For buckthorn and potato aphids.
• gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d, REI 48h, Bee: H. See resistance statement on label. 
• lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d, REI 24h, Bee: H. See resistance statement on label.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A, 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.

IRAC Group 4:

• acetamiprid (Assail 30SG): 2.5 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
• clothianidin (Belay): 2 to 3 oz/A foliar, 9 to 12 oz/A soil (in-furrow or sidedress), 0.4 to 0.6 oz/100 lb seed for seed-piece application; PHI 14d foliar, REI 12h, Bee: H, Group 4A. 
• dinotefuran (Venom): 1 to 1.5 oz/A foliar, 6.5 to 7.5 oz/A soil preplant, preemergence, or ground crack; PHI 7d foliar, REI 12h, Bee: H, Group 4A. For green peach and potato aphid suppression only.
• flupyradifurone (Sivanto): 10.5 to 14 oz/A green peach aphid, 7 to 14 oz/A other aphids; PHI 7d, REI 4h, Bee: L, Group 4D. Foliar applications only.
• imidacloprid (Admire Pro): 1.3 oz/A foliar, 5.7 to 8.7 oz/A soil; PHI 7d foliar, REI 12h, Bee: H, Group 4A.
• imidacloprid plus mancozeb (TOPS-MZ-Gaucho): 0.75 lb/100 lb seed-pieces; REI 48h, Bee: H, Group 4A. Seed-piece treatment only. Do not make subsequent application of another neonicotinoid (Group 4) insecticide following a seed-piece treatment. Check registration in your state. 
• sulfoxaflor (Transform WG): 0.75 to 1.5 oz/A; PHI 7d, REI 24h, Bees: H, Group 4C. Do not use in greenhouses or high tunnels.
• thiamethoxam (Actara): 3 oz/A; PHI 14d, REI 12h, Bee: H, Group 4A.
• thiamethoxam (Cruiser 5FS): 0.11 to 0.16 oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. Application rates vary based on potato seeding rate (see label). For early-season protection.
• thiamethoxam (Platinum 75SG): 1.66 to 2.67 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at planting.

IRAC Group 8:

• sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 24h, Bee: L, Group 8D. Do not apply in midday sun or mix with copper.

IRAC Group 9:

• pymetrozine (Fulfill): 2.75 to 5.5 oz/A; PHI 14d, REI 12h, Bee: L, Group 9B. Translaminar. 

IRAC Group 23:

• spirotetramat (Movento): 4 to 5 oz/A; PHI 7d, REI 24h, Bee: M. Must be tank-mixed with a spray adjuvant with spreading and penetrating properties to maximize leaf uptake and systemicity. Don't use sticker adjuvants. Controls immature stages, may also reduce adult fertility. Do not use in greenhouses or high tunnels.

IRAC Group 28:

• chlorantraniliprole plus lambda-cyhalothrin (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.
• cyantraniliprole (Verimark): 13.5 oz/A for soil applications, 0.46-0.75 oz/100 lb of seed-pieces; REI 4h, Bee: H. For soil applications at planting and as seed-piece treatments. For suppression of green peach aphid only.

IRAC Group 29:

• flonicamid (Beleaf 50SG): 2 to 2.8 oz/A; PHI 7d, REI 12h, Bee: L.

IRAC Group UN:

• azadirachtin (Azatin O^OG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake. 
• Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M.
• insecticidal soap (M-Pede^OG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Apply with a labeled companion insecticide for enhanced and residual control. Do not mix with sulfur.  
• mineral oil (SuffOil-X^OG): 1 to 2 gal/100 gal water; PHI 0d, REI 4h, Bee: L. Apply as needed. 

Colorado Potato Beetle (Leptinotarsa decemlineata)

Colorado potato beetles (CPB) are 1/2" long by 3/8" wide, oval with a rounded back, and each forewing is yellow with five black stripes. CPB overwinters in the adult stage, primarily in soil (up to 12" deep) in the woods and brushy borders next to host crops, though some burrow into soil in the field. In spring, the beetles search for food plants by walking from the field edges. Heavy feeding may occur on edges on non-rotated fields. If beetles do not find host plants via walking they will fly in search of food.

In the Northeast, CPB survives on solanaceous crops and weeds, including horsenettle, nightshade, eggplant, potato, and tomato (primarily seedlings). Once host plants are found adults feed, mate and lay clumps of 30-35 bright yellow eggs on the undersides of leaves. Eggs hatch in 7-10 days, depending on temperature. The larva is hump-backed, rusty-red with 2 rows of black dots along each side of its body. Feeding damage and larvae are easily seen on leaves. Larvae grow through 4 stages (instars) and reach 5/8" long before they drop to the soil and pupate. Because the last instar does 85% of the feeding damage it is critical to control larvae while they are small. Adults emerge from pupae after 10-14 days. In southern New England, there is a second generation of eggs, larvae, and adults, while in northern New England there is 1 generation.

Cultural Controls. The single most important tactic for CPB management is to rotate potatoes, eggplant, and tomato to a field that is at least 200 yards from the previous year's fields. Barriers such as roads, rivers, woodlands, and fields with other crops are helpful. This single practice delays colonization and reduces population densities.

Mechanical barriers such as trench traps, trap crops, and straw mulch also delay and reduce infestation. Install plastic-lined trench traps next to overwintering sites at least 1 week before adults emerge. Trenches should be 1' to 2' deep and 6" to 24" wide at the top. They can be U- or V-shaped with side walls sloping at angles between 65° and 90°. Beetles walking from field borders fall into the trench and cannot fly out. Perimeter trap crops may be potatoes planted earlier than the main crop to attract beetles before the main crop emerges, or planted between overwintering sites and this season's crop. Flame, vacuum, or spray the border crop before beetles move into the main crop. Another approach is to plant 3-5 rows of potatoes treated with a systemic insecticide in a perimeter around the field; this treated border will kill up to 80% of the colonizing beetles. Straw mulch around the host crop has been shown to reduce beetle numbers. Late planting may cause beetles to leave the field before potatoes emerge, resulting in lower beetle numbers.

Natural enemies that attack CPB eggs or larvae include twelve-spotted ladybeetle, spined soldier bug, the carabid beetle Lebia grandis, and a parasitic tachinid fly. The entomopathogenic fungus Beauvaria bassiana has been shown to suppress beetle populations though it does not provide immediate control.

CPB rapidly develops resistance to insecticides. This can happen in as short a time as 1 year and is likely whenever a single class of insecticide is used multiple times against the same population in the same and succeeding years. The population on a single farm may develop resistance in response to management practices on that farm. Resistance to pyrethroids (IRAC Group 3A) and neonicotinoids (Group 4A) exists in parts of New England.

Wherever possible, growers should rotate classes of insecticides and avoid using the same chemistry more than once per year, or better, once every other year. Do not use the same chemical class on successive generations in the same year. There are enough different classes to allow this, if you plan carefully. Note the resistance group number of each insecticide and avoid using chemistries from the same group. Use newer chemistries first.

Do not try to kill every beetle in the field. Potato crops can withstand 15% defoliation without affecting yields. Avoid spraying CPB late in the season, as food reserves in the foliage 2 weeks prior to senescence add little to final tuber bulking.

Scout to determine whether or not a damaging population is present. When using products that control only larvae, scout for eggs, note egg hatch, and apply controls before larvae reach third instar. For materials that control all stages, you may wait and scout for adults and larvae to determine the need to apply insecticides.

To use the threshold table below, walk the field in a V-shaped pattern and select 50 potato stalks at intervals, e.g., every 10-20 paces, depending on field size. Count adults, large larvae (greater than half-grown), and small larvae (less than half-grown) separately. If the number of CPB is high, an insecticide should be applied; if the number is low, no insecticide is required for that week. If the number of CPB is between high and low, no insecticide should be applied, but the field should be checked in 3-5 days. Otherwise, the field should be checked weekly. These thresholds are for mid-season. Late in the season, potato plants can tolerate more defoliation without affecting yields.

Colorado Potato Beetle Action Thresholds

IRAC Group 1:

• oxamyl (Vydate* C-LV): 8.5 to 34 oz/A; PHI 7d, REI 48h, Bee: H, Group 1A. Vydate* L is NOT labeled for potatoes.
• phorate (Thimet* 20G): 13 to 17.3 oz/1000 row ft in heavy or clay soils for at-planting applications; 8.5 to 11.3 oz/1000 row ft in light or sandy soils for post-emergence applications; PHI 90d, REI 48h, Bee: H, Group 1B. Apply at planting in heavy soil. Granules must be incorporated into the soil. Apply post-emergence on sandy soil. 

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 3.2 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H. See resistance statement on label.
• beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H. See resistance statement on label.
• deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H. See resistance statement on label. 
• esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H.
• gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d, REI 48h, Bee: H. See resistance statement on label.
• lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d, REI 24h, Bee: H. See resistance statement on label.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 14d, REI 12h, Bee: H.
• pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
• zeta-cypermethrin (Mustang* Maxx): 3.2 to 4 oz/A; PHI 1d, REI 12h, Bee: H. See resistance statement on label.

IRAC Group 4:

•  acetamiprid (Assail 30SG): 1.5 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
• clothianidin (Belay): 2 to 3 oz/A foliar, 9 to 12 oz/A soil (in-furrow or sidedress), 0.4 to 0.6 oz/100 lb of seed-pieces; PHI 14d foliar, REI 12h, Bee: H, Group 4A. Will not control CPB in regions where insensitivity to neonicotinoid insecticides has been reported.
• dinotefuran (Venom): 1 to 1.5 oz/A foliar, 6.5 to 7.5 oz/A soil preplant, preemergence, or ground crack; PHI 7d foliar, REI 12h, Bee: H, Group 4A. 
• flupyradifurone (Sivanto): 10.5 to 14 oz/A; PHI 7d, REI 4h, Bee: L, Group 4D. Foliar applications only.
• imidacloprid plus mancozeb (TOPS-MZ-Gaucho): 0.75 lb/100 lb seed-pieces; REI 48h, Bee: H, Group 4A. Seed-piece treatment only. Do not make subsequent application of another neonicotinoid (Group 4A) insecticide following a seed-piece treatment. Check registration in your state.
• thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 14d, REI 12h, Bee: H, Group 4A.
• thiamethoxam (Cruiser 5FS): 0.11 to 0.16 oz/100 lb of seed; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. Application rates vary based on potato seeding rate (see label). For early-season protection.
• thiamethoxam (Platinum 75SG): 1.66 to 2.67 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at planting.

IRAC Group 5:

• spinetoram (Radiant SC): 4.5 to 8 oz/A; PHI 7d, REI 4h, Bee: M.
• spinosad (Entrust SC^OG): 3 to 10 oz/A; PHI 7d, REI 4h, Bee: M. 

IRAC Group 6:

•  abamectin (Agri-Mek* SC): 1.75 to 3.5 oz/A; PHI 14d, REI 12h, Bee: H. Make first application at 50% egg hatch. If 2 applications are needed, limit to single application per CPB generation.

IRAC Group 15:

• novaluron (Rimon 0.83EC): 6 to 12 oz/A; PHI 14d, REI 12h, Bee: L. Do not apply to successive generations. Most effective on 1st and 2nd instars. No activity against adult beetles.

IRAC Group 17:

• cyromazine (Trigard): 2.66 oz/A or 5.32 oz/A; PHI 17d, REI 12h, Bee: M. Insect growth regulator most effective on 1st or 2nd instar larvae. Does not control adult beetles.

IRAC Group 22:

• indoxacarb (Avaunt): 3.5 to 6 oz/A; PHI 7d, REI 12h, Bee: H. Efficacy may be improved by the addition of piperonyl butoxide (PBO).

IRAC Group 28:

• chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 14d, REI 4h, Bee: L. Apply as a foliar or overhead chemigation spray. Do not apply more than twice to one generation or within a 30-day period.
• chlorantraniliprole plus lambda-cyhalothrin (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.
• cyantraniliprole (Verimark): 6.75 to 13.5 oz/A soil, 0.46 to 0.75 oz/100 lb of seed-pieces; REI 4h, Bee: H. For soil applications at planting and as seed-piece treatment. See resistance statement on label. 

IRAC Group 35:

• ledprona (Calantha*): 12 to 16 oz/A; REI 4h, Bee: L. Most effective on young larvae.

IRAC Group UN:

• azadirachtin (Azatin O^OG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
• Beauveria bassiana (Mycotrol ESO^OG): 0.5 to 1 qt/A; PHI 0d, REI 4h, Bee: L. Apply up to 3 qt/A for high pest pressure and/or dense foliage.

Cutworms

Cutworms are caterpillars that hide under the soil surface adjacent to the plant stem during the day and feed after dark. Larvae may feed on leaves, cut stems, or even occasionally feed on tubers. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids (Group 3A) may work best during cool spring weather. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on black and variegated cutworms.

IRAC Group 1:

• carbaryl (10% Sevin Granules): 20 lb/A; PHI 7d, REI 12h, Bee: H, Group 1A. Apply evenly over soil surface.
• methomyl (Lannate* LV): 1.5 pt/A; PHI 6d, REI 48h, Bee: H, Group 1A. Variegated cutworm only.

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 1.3 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H.
• beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H.
• deltamethrin (Delta Gold*): 1 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H.
• esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H.
• gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 7d, REI 48h, Bee: H.
• lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 7d, REI 24h, Bee: H.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 5 to 8 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 14d, REI 12h, Bee: H.
• zeta-cypermethrin (Mustang* Maxx): 1.28 to 4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 5:

• spinosad (Seduce^OG): 20 to 44 lb/A, 0.5 to1 lb/1000 sq ft.; PHI 7d, REI 4h, Bee: M. Spread bait on soil around plants.

IRAC Group 11:

• Bacillus thuringiensis aizawai (XenTari^OG): 0.5 to 1.5 lb/A; PHI 0d, REI 4h, Bee: L. Must be ingested. For resistance management, may be rotated with Bt kurstaki products (Dipel).
• Bacillus thuringiensis kurstaki (Dipel DF^OG): 0.5 to 2 lb/A; PHI 0d, REI 4h, Bee: L. Must be ingested. For resistance management, may be rotated with Bt aizawai products (Xentari).

IRAC Group 28:

• chlorantraniliprole and lambda-cyhalothrin (Besiege*): 5 to 8 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.

European Corn Borer (Ostrinia nubilalis)

Larvae infest potato stems but rarely cause yield reductions; however, larval infestations can exacerbate drought stress. Higher levels of stem infestations have been associated with a higher incidence of blackleg. For more information on ECB, see the Sweet Corn section. 

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H.
• beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H.
• deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H.
• esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H.
• gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d, REI 48h, Bee: H.
• lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d, REI 24h, Bee: H.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 14d, REI 12h, Bee: H.
• zeta-cypermethrin (Mustang* Maxx): 1.76 to 4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 4:

• acetamiprid (Assail 30SG): 2.5 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A. 

IRAC Group 5:

• spinetoram (Radiant SC): 6 to 8 oz/A; PHI 7d, REI 4h, Bee: M.
• spinosad (Entrust SC^OG): 3 to 10 oz/A; PHI 7d, REI 4h, Bee: M.

IRAC Group 15:

• novaluron (Rimon 0.83EC): 6 to 12 oz/A; PHI 14d, REI 12h, Bee: L. Most effective on 1st and 2nd instars.

IRAC Group 22:

• indoxacarb (Avaunt): 3.5 to 6 oz/A; PHI 7d, REI 12h, Bee: H.

IRAC Group 28:

• chlorantraniliprole (Coragen): 3.5 to 7.5 oz/A; PHI 14d, REI 4h, Bee: L. Apply as a foliar or overhead chemigation spray.
• chlorantraniliprole and lambda-cyhalothrin (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.
• cyantraniliprole (Verimark): 10 to 13.5 oz/A soil, 0.46 to 0.75 oz/100 lb of seed-pieces; REI 4h, Bee: H. For soil applications at planting and as seed-piece treatments.

IRAC Group UN:

• Burkholderia spp. strain A396 (Venerate XC^OG): 1 to 4 qt/A; PHI 0d, REI 4h, Bee: M.
• Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 1 to 3 lb/A; PHI 0d, REI 4h, Bee: M.

Flea Beetles, Potato (Epitrix cucumeris) and Eggplant (E. fuscula)

Flea beetles are shiny black beetles less than 1/8" long. Adults spend the winter under plant residue along tree lines or in the field. In the early spring, they feed on solanaceous weeds until they move to potato or other solanaceous crops. Numerous tiny feeding shot holes can injure leaves and stunt young plants. Management practices include clean cultivation, crop rotation, delayed plantings, removing or avoiding spring weed hosts, use of row covers, and applying spot treatments targeting young potato plants along the field edges. Full-size plants rarely require treatment for flea beetles. Most insecticides registered to control CPB, including spinosad, will control FB. Sweep young plants 25 times and spot treat potatoes along field edges if 50 beetles are found in the sweep net.

IRAC Group 1:

• carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 7d, REI 12h, Bee: H, Group 1A. Do not apply to crops or weeds in bloom. 
• methomyl (Lannate* LV): 1.5 pt/A; PHI 6d, REI 48h, Bee: H, Group 1A.
• phorate (Thimet* 20G): 8.5 to 11.3 oz/1000 row ft in light or sandy soils, 13 to 17.3 oz/1000 row ft in heavy or clay soils; PHI 90d, REI 48h, Bee: H, Group 1B. May only be applied at planting in sandy or clay soils. Granules must be incorporated into soil. For control of larvae and reduction of adults.

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H.
• beta-cyfluthrin (Baythroid* XL): 1.6 to 2.8 oz/A; PHI 0d, REI 12h, Bee: H.
• bifenthrin (Brigade* 2EC): 3.2 to 9.6 oz/A at cultivation or lay-by, 2.1 to 6.4 oz/A foliar; PHI 21d, REI 12h, Bee: H. Sweet potato and black flea beetles only. Apply as foliar spray to control adults only.
• deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H.
• esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H. 
• gamma-cyhalothrin (Declare*): 1.02 to 1.54 oz/A; PHI 7d, REI 48h, Bee: H. Adults only.
• lambda-cyhalothrin (Warrior* II): 1.28 to 1.92 oz/A; PHI 7d, REI 24h, Bee: H. Adults only.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 14d, REI 12h, Bee: H.
• pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
• zeta-cypermethrin (Mustang* Maxx): 1.76 to 4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 4:

• acetamiprid (Assail 30SG): 1.5 to 2.5 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
• clothianidin (Belay): 2 to 3 oz/A foliar, 9 to 12 oz/A soil (in-furrow or sidedress), 0.4 to 0.6 oz/100 lb of seed-pieces; PHI 14d foliar, REI 12h, Bee: H, Group 4A. 
• dinotefuran (Venom): 1 to 1.5 oz/A foliar, 6.5 to 7.5 oz/A soil preplant, preemergence, or ground crack; PHI 7d foliar, REI 12h, Bee: H, Group 4A. 
• imidacloprid (Admire Pro): 1.3 oz/A foliar, 5.7 to 8.7 oz/A soil; PHI 7d foliar, REI 12h, Bee: H, Group 4A.
• imidacloprid plus mancozeb (TOPS-MZ-Gaucho): 0.75 lb/100 lb of seed-pieces; REI 48h, Bee: H, Group 4A. Seed-piece treatment only. Do not make subsequent application of another neonicotinoid (Group 4A) insecticide following a seed-piece treatment. Check registration in your state.
• thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 14d, REI 12h, Bee: H, Group 4A.
• thiamethoxam (Cruiser 5FS): 0.11 to 0.16 oz/100 lb seed; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. Application rates vary based on potato seeding rate (see label). For early-season protection.
• thiamethoxam (Platinum 75SG): 1.66 to 2.67 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at planting.

IRAC Group 28:

• chlorantraniliprole and lambda-cyhalothrin (Besiege*): 6 to 9 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.
• cyantraniliprole (Verimark): 10 to 13.5 oz/A soil, 0.46 to 0.75 oz/100 lb of seed-pieces; REI 4h, Bee: H. For soil applications at planting and as seed-piece treatments. For suppression of potato flea beetle at planting.

IRAC Group UN:

• kaolin (Surround WP^OG): 25 to 50 lb/A, 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression only. Supplemental controls may be needed for complete control.

Potato Leafhopper (Empoasca fabae)

Potato leafhoppers overwinter in Louisiana and vicinity and move north on storm fronts into the central states and then into New England on winds from the west. Low levels of leafhopper feeding can severely damage plants and cause symptoms known as hopperburn. Leaves yellow, turn brown and die. Adults are light green, 1/8" long, and wedge-shaped, while nymphs are bright green, flatter and fatter than adults, and move sideways in a crab-like fashion. Sample with sweep net, or shake plants to see if adults fly up, and treat if more than 1 adult per sweep is found. Nymphs can be monitored by visually inspecting lower leaf surfaces on lower leaves. Treat if more than 15 nymphs are found per 50 leaves.

IRAC Group 1:

• carbaryl (Sevin XLR Plus): 0.5 to 1 qt/A; PHI 7d, REI 12h, Bee: H, Group 1A. Do not apply to crops or weeds in bloom. 
• dimethoate (Dimethoate 4EC): 0.5 to 1 pt/A; PHI 0d, REI 48h, Bee: H, Group 1B.
• malathion (Malathion 57EC): 1 to 1.5 pt/A; PHI 0d, REI 12h, Bee: H, Group 1B.
• methomyl (Lannate* LV): 1.5 to 3 pt/A; PHI 6d, REI 48h, Bee: H, Group 1A.
• oxamyl (Vydate* C-LV): 17 to 34 oz/A; PHI 7d, REI 48h, Bee: H, Group 1A. Vydate* L is NOT labeled for potatoes.
• phorate (Thimet* 20G): 8.5 to 11.3 oz/1000 row ft in light or sandy soils, 13 to 17.3 oz/1000 row ft in heavy or clay soils; PHI 90d, REI 48h, Bee: H, Group 1B. May be applied at planting in sandy or clay soils. Granules must be incorporated into soil. May be applied post-emergence on sandy soils only. 

IRAC Group 3:

• alpha-cypermethrin (Fastac* CS): 1.8 to 3.8 oz/A; PHI 1d, REI 12h, Bee: H.
• beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A; PHI 0d, REI 12h, Bee: H.
• deltamethrin (Delta Gold*): 1.5 to 2.4 oz/A; PHI 3d, REI 12h, Bee: H.
• esfenvalerate (Asana * XL): 5.8 to 9.6 oz/A; PHI 7d, REI 12h, Bee: H.
• gamma-cyhalothrin (Declare*): 0.77 to 1.28 oz/A; PHI 7d, REI 48h, Bee: H.
• lambda-cyhalothrin (Warrior* II): 0.96 to 1.6 oz/A; PHI 7d, REI 24h, Bee: H.
• lambda-cyhalothrin plus chlorantraniliprole (Besiege*): 5 to 8 oz/A; PHI 14d, REI 24h, Bee: H, Groups 3A & 28.
• permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A; PHI 14d, REI 12h, Bee: H.
• pyrethrin (PyGanic EC5.0^OG): 4.5 to 15.61 oz/A; 0.25 to 0.50 oz/gal, 3 gal/1000 sq ft in greenhouse for backpack sprayers; PHI 0d, REI 12h, Bee: M.
• zeta-cypermethrin (Mustang* Maxx): 3.2 to 4 oz/A; PHI 1d, REI 12h, Bee: H.

IRAC Group 4: 

• acetamiprid (Assail 30SG): 1.5 to 4 oz/A; PHI 7d, REI 12h, Bee: M, Group 4A.
• clothianidin (Belay): 2 to 3 oz/A foliar, 9 to 12 oz/A soil (in-furrow or sidedress), 0.4 to 0.6 oz/100 lb of seed-pieces; PHI 14d foliar, REI 12h, Bee: H, Group 4A. 
• dinotefuran (Venom): 1 to 1/5 oz/A foliar, 6.5 to 7.5 oz/A soil preplant, preemergence, or ground crack; PHI 7d foliar, REI 12h, Bee: H, Group 4A. 
• flupyradifurone (Sivanto): 7 to 14 oz/A; PHI 7d, REI 4h, Bee: L, Group 4D. Foliar applications only.
• imidacloprid (Admire Pro): 1.3 oz/A foliar, 5.7 to 8.7 oz/A soil; PHI 7d foliar, REI 12h, Bee: H, Group 4A.
• imidacloprid plus mancozeb (TOPS-MZ-Gaucho): 0.75 lb/100 lb of seed-pieces; REI 48h, Bee: H, Group 4A. Seed-piece treatment only. Do not make subsequent application of another neonicotinoid (Group 4A) insecticide following a seed-piece treatment. Check registration in your state. 
• sulfoxaflor (Transform WG): 1.5 to 2.25 oz/A; PHI 7d, REI 24h, Bees: H, Group 4C. Do not use in greenhouses or high tunnels.
• thiamethoxam (Actara): 1.5 to 3 oz/A; PHI 14d, REI 12h, Bee: H, Group 4A.
• thiamethoxam (Cruiser 5FS): 0.11 to 0.16 oz/100 lb seed; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. Application rates vary based on potato seeding rate (see label). For early-season protection.
• thiamethoxam (Platinum 75SG): 1.66 to 2.67 oz/A; REI 12h, Bee: H, Group 4A. Systemic insecticide used at planting.

IRAC Group 8:

• sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal; REI 24h, Bee: L, Group 8D. Do not apply in midday sun or mix with copper.

IRAC Group 21:

• fenpyroximate (Portal XLO): 2 pt/A; PHI 7d, REI 12h, Bee: L.

IRAC Group 28:

• chlorantraniliprole plus lambda-cyhalothrin (Besiege*): 5 to 8 oz/A; PHI 14d, REI 24h, Bee: H, Groups 28 & 3A.

IRAC Group 30:

• isocycloseram (Zivalgo): 0.7 to 2 oz/A; PHI 14d, REI 12h, Bee: H. Foliar application of this product is prohibited from onset of flowering until flowering is complete unless application is made between 3pm to 10am, or temperature is less than 50°F.

IRAC Group UN:

• azadirachtin (Azatin O^OG): 4 to 16 oz/A foliar or drench, 4 to 16 oz/100 gal in greenhouses; PHI 0d, REI 4h, Bee: L. When using lower rates, combine with adjuvant for improved spray coverage and translaminar uptake.
• Chromobacterium subtsugae strain PRAA4-1 (Grandevo^OG): 2 to 3 lb/A; PHI 0d, REI 4h, Bee: M.
• insecticidal soap (M-Pede^OG): 1.25 to 2.5 oz/gal water; PHI 0d, REI 12h, Bee: L. Apply with a labeled  companion insecticide for enhanced and residual control. Do not mix with sulfur.  
• kaolin (Surround WP^OG): 25 to 50 lb/A, 0.25 to 0.5 lb/gal; PHI 0d, REI 4h, Bee: L. Suppression only. Supplemental controls may be needed for complete control.
• paraffinic oil (Organic JMS Stylet-Oil^OG): 3 to 6 qt/100 gal water; PHI 0d, REI 4h, Bee: L.

Wireworms, including Corn Wireworm (Melanotus communis)

Corn wireworm is reported to be the most common wireworm species in the Northeast, but others may also be present, including the tobacco wireworm (Conodoerus verspertinus). Corn wireworm causes damage to many vegetable crops including cabbage, corn, lettuce, pepper, potato, and sweet potato, as well as field crops including field corn, sorghum, soybean, tobacco, and wheat. Wireworms are attracted to germinating seeds and can be a seed pest in large-seeded crops such as beans, peas, and corn.

Wireworms are the underground larval stage of click beetles, which are elongated, brown beetles that snap their bodies to make a clicking sound. Adults emerge from the soil in May and June and tend to hide during the day and fly mostly at night. Egg-laying females prefer grassy or weedy fields. Eggs are deposited in the soil, often in batches. Larvae are slender, yellow-brown, hard-shelled, and shiny, with 3 pairs of legs. Wireworms spend multiple years in the soil, and completing their development from egg to adult may take 2-5 years depending on conditions. They feed on other insects, roots, seeds, tubers, and other plant tissue. Wireworms prefer wet soils and moderate temperatures (at least 70º F); they migrate up to reach warmer soils, but down to avoid excessive cold, heat, or drought. In agricultural fields, where other plants are eliminated, the crop itself is the primary available food source. Wireworms may injure potatoes by feeding on the seed piece, resulting in weak stands, but the majority of their damage is caused by tunneling into tubers which reduces yield quality. Wireworm tunnels also provide entry to tuber pathogens, increasing incidence of tuber rots.

Tuber damage may be worse under drought conditions, where the crop provides the only source of moisture in a dry field. Wireworms are more pronounced in soils that are wet, heavy, or high in organic matter. They may be worse in low areas of the field; however, they will move away from saturated soils that lack oxygen. Wireworm problems occur most often in fields that were recently in hay, pasture, or sod (within the past 3 years), had grassy weeds in previous years, or were in sorghum-sudangrass or grass cover crops or cereal grains. Forest soils may also harbor wireworms; thus recently cleared land can be infested. The most important method of wireworm control is to avoid planting potatoes or other susceptible crops in infested fields.

Baits using corn, wheat, or rolled oats placed 6-8" deep can be used to determine if wireworms are present, but these sampling methods are labor intensive, and potatoes are often planted in cold soils before such samples could be completed. A review of many insecticide trials over 2 decades indicated that organophosphate insecticides (IRAC Group 1B) applied as a preplant broadcast or in-furrow gave better control than carbamates (Group 1A), and that fipronil and bifenthrin were as effective as the organophosphates, but with less environmental impact and potential human safety concerns.

IRAC Group 1:

• ethoprop (Mocap* 15G): 1.4 lb/1000 row feet banded, 27 to 40 lb/A broadcast; REI 48h, Bee: H, Group 1B. Apply before potato emergence only. Direct contact with seed-pieces may contribute to delayed emergence. Extremely toxic to birds. Do not leave granules on soil surface. Apply only once during the growing season.
• phorate (Thimet* 20G): 8.5 to 11.3 oz/1000 row ft in light or sandy soils, 13 to 17.3 oz/1000 row ft in heavy or clay soils; PHI 90d, REI 48h, Bee: H, Group 1B. May be applied at planting in sandy or clay soils. Granules must be incorporated into soil. May be applied post-emergence for suppression only of wireworms on sandy soils only. 

IRAC Group 2:

• fipronil (Regent* 4SC): 3.2 oz/A; PHI 90d, REI 0d, Bee: H. Make one in-furrow treatment at planting. Must be thoroughly incorporated and covered with soil immediately after application. Do not use as T-band over the top of closed furrow. Do not apply through irrigation system.

IRAC Group 3:

• bifenthrin (Brigade* 2EC): 9.6 to 19.2 oz/A at planting for corn and tobacco wireworm, 3.2 to 9.6 oz/A at cultivation or lay-by, 2.1 to 6.4 oz/A foliar for southern potato wireworm; PHI 21d, REI 12h, Bee: H. May be applied as foliar spray for click beetle (adult wireworm).

IRAC Group 4:

• imidacloprid plus mancozeb (TOPS-MZ-Gaucho): 0.75 lb/100 lb of seed-pieces; REI 48h, Bee: H, Group 4A. Seed-piece treatment only. Do not make subsequent application of another neonicotinoid (Group 4A) insecticide following a seed-piece treatment. Check registration in your state.
• thiamethoxam (Cruiser 5FS): 0.11 to 0.16 oz/100 lb of seed-pieces; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. Application rates vary based on potato seeding rate (see label). For early-season protection. 
• thiamethoxam (Platinum 75SG): 1.66 to 2.67 oz/A; REI 12h, Bee: H, Group 4A. Systemic seed-piece treatment. 

IRAC Group UN:

• Burkholderia spp. strain A396 (Majestene^OG): 4 to 8 qt/A preplant, at planting, or shortly after as broadcast, soil or chemigation, 1 to 16 oz/100 lb of seed-pieces; PHI 0d, REI 4h, Bee: M. Suppression only.
• Isaria fumosorosea Apopka Strain 97 (PFR-97 20% WDG^OG): 1 to 2 lb/A soil; PHI 0d, REI 4h, Bee: M.