Insect Control

NOTE:  For the insecticides listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, days to harvest (dh), REI, and special instructions. In many cases there are other products available with the same active ingredient. Please see Table 20 and Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

Caution: Insecticides should not be applied when bees are active in the field. If application of an insecticide is necessary during blossom, apply it in the evening after the bees have left the field. Pyrethroids and carbamates are highly toxic to honey bees. Neonicotinoids are highly toxic to bees and are labeled for soil application only in cucurbits.

Aphids

Aphids found in cucurbits include green peach aphid and melon aphid. See Peppers for more information about green peach aphid. Melon aphid has a wide host range; vegetable crops attacked include cucurbits, asparagus, pepper, eggplant and okra. Among cucurbits, it is more serious on cucumber, muskmelon and watermelon than in squash and pumpkins. Varieties differ in susceptibility. Melon aphid overwinters in the north on woody plants including catalpa and rose of Sharon; more southerly, adults survive on cold tolerant plants including spinach and dock. Life cycle is similar to green peach aphid; winged females colonize crops in early summer, and wingless females produce live young for about 15 days (70-80 offspring per female) resulting in multiple generations. The time from birth to reproductive adult can be one week. Wingless females are 1-2 mm long. Color varies from light green mottled with dark green (most common) to white, yellowish or dark green. The cornicles at tip of abdomen are always black, a key diagnostic feature. Melon aphid outbreaks are more common in hot, dry weather.

Infestations occur on undersides of leaves where aphids extract plant sap with their piecing sucking mouthparts. Feeding causes yellowing, puckering, leaf curling, and leaf death at high numbers along with shiny honeydew deposits and buildup of sooty mold. Viruses transmitted by melon aphid include cucumber mosaic, watermelon mosaic, and zucchini yellow mosaic. Because transmission occurs within 15 seconds of feeding, insecticides may not prevent initial virus infection though they may reduce its spread in the crop. Oils may reduce virus transmission but test for phytotoxicity.

Use row covers or reflective plastic mulch to prevent early infestation and virus transmission (direct seeding is recommend in reflective mulch for maximum effectiveness). Cultivars differ in susceptibility to aphid buildup and to virus; plant resistant varieties if they are available. Separate early and late plantings. Use selective insecticides for other pests to conserve natural enemies.

Scout for aphids beginning in mid June by searching undersides of leaves on runners. If 20 percent of runners or more have live aphids treatment may be needed. Good coverage of undersides of leaves is needed for control.

acetamiprid (Assail 30 SG): 2.5 to 4 dry oz/A (7 dh, REI 12h, Group 4). Toxic to bees exposed to direct treatment; do not apply while bees are active.

azadirachtin (Neemix 4.5): 5 to 7 oz/A (0 dh, REI 12h, Group 18). Suppression and adult feeding deterrence. OMRI listed.

bifenthrin (Capture* 2EC): 2.6 to 6.4 oz/A (3 dh, REI 12h, Group 3A).

dimethoate (Dimethoate 4EC): 1/2 to 2 pt/A for watermelon; 1 pt/A for other melons (3 dh, REI 48h, Group 1B). Do not use on cucumbers.

dinotefuran (Safari 20SG): 0.16 to 0.32 dry oz/1,000 sq ft or 3.5 to 7 dry oz/100 gal/20,000 sq ft (1 dh, REI 12h, Group 4). Cucumber and melon transplants while in greenhouse. Not for field use.

dinotefuran (Venom 20SG): 7 to 14 dry oz/A foliar or 18 to 21 dry oz/A soil (1 dh foliar, 21 dh soil, REI 12h, Group 4A). For resistance management purposes, do not use foliar spray after soil application or following another nicotinoid (Group 4A) insecticide application on the same crop. Highly toxic to bees, avoid foliar application during bloom. 

endosulfan (Thionex* 50W): 1 to 2 lbs/A (2 dh, REI 24h, Group 2A).

flonicamid (Beleaf 50SG): 2 to 2.8 dry oz/A (0 dh, REI 12, Group 9C).

imidacloprid (Admire Pro): 7 to 10.5 oz/A (21 dh, REI 12h, Group 4A). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. May also be used in planthouse at 0.44 oz/10,000 plants. See plant-back restrictions. Note: Provado IS NOT registered for use on cucurbits.

insecticidal soap (M-Pede): 1.25 to 2.5 oz/gal water (0 dh, REI 12h). Spray to wet all infested plant surfaces. May require repeated applications. Apply with another aphicide. OMRI listed.

lambda-cyhalothrin (Warrior*): 3.8 oz/A (1 dh, REI 24h, Group 3A).

malathion (Malathion 57 EC): 1 1/2 pt/A (1 dh, REI 12h, Group 1B). Do not apply unless plants are dry.

methomyl (Lannate* SP): 1/2 to 1 lb/A (1 dh for 1/2 lb/A; 3 dh for over 1/2 lb/A, REI 48h, Group 1A). For melon aphid.

pymetrozine (Fulfill): 2.75 oz/A (0 dh, REI 12h, Group 9A). For both melon and green peach aphid. Thorough spray coverage of plant foliage is essential for optimum control. Translaminar.

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). OMRI listed. May be used in greenhouse or field.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A).  May be used in greenhouse or field.

sodium tetraborohydrate decahydrate (Prev-AM): 100 oz/100 gal (0.5 dh, REI 12h, Group 25). Do not apply in midday sun or mix with copper, sulfur or oils. CT only.

thiamethoxam (Actara): 2 to 3 oz/A (0 dh, REI 12h, Group 4). Highly toxic to bees exposed to direct treatment or residues on blooming crops. Do not apply or allow to drift to blooming crops or weeds. Wait at least 5 days before placing beehives in or near the treated field.

thiamethoxam (Platinum): 5 to 11 oz/A (30 dh, REI 12h, Group 4). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. DO NOT apply as a foliar spray.

Cucumber Beetle

Striped cucumber beetles are about 7mm long, yellow with three black stripes that reach the end of the forewings, a yellow thorax and black head. Adults overwinter in field edges near last year’s crop, with a small proportion remaining in the field. With the onset of warm days, beetles move rapidly into young crops. Adults cause direct feeding damage to cotyledons, leaves and the base of the stem. Eggs are laid in soil and larvae feed on roots. After the pupal stage is completed in the soil, summer adults emerge. These adult beetles congregate in flowers and may cause damage to fruit.

Beetle feeding spreads bacterial wilt to young plants, especially before the 5-leaf stage. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. To prevent bacterial wilt in susceptible crops, scout for beetles twice weekly at the seedling stage. Treat when beetle numbers reach 1 beetle per 2 plants, up to the five leaf stage.

Use crop rotation to reduce beetle numbers. Spunbonded row covers exclude beetles; use hoops to prevent abrasion and remove at flowering to allow pollination. Transplants may allow plants to reach a later growth stage before beetles arrive. Some repellents or systemics may be applied to transplants outside the greenhouse before setting in the field, which is convenient and allows lower rates of application. Some may be applied through drip irrigation. Use a perimeter trap crop of Blue Hubbard or another Cucurbita maxima variety and treat borders with a systemic at planting or with a foliar insecticde as soon as the first beetles arrive, to protect a main crop of cucumbers and melons from beetle damage. If multiple treatments are needed, rotate to a product with a different mode of action (different group number).

acetamiprid (Assail 30 SG): 2.5 to 5.3 dry oz/A (7 dh, REI 12h, Group 4). Toxic to bees exposed to direct treatment; do not apply while bees are active.

beta-cyfluthrin (Baythroid* XL): 2.4 to 2.8 oz/A (0 dh, REI 12h, Group 3A).

bifenthrin (Capture* 2 EC): 2.6 to 6.4 oz/A (3 dh, REI 12h, Group 3A).

carbaryl (Sevin XLR Plus): 1 qt/A (3 dh, REI 12h, Group 1A). Highly toxic to bees; avoid use during bloom when bees are active; apply in evening. May encourage buildup of aphids by killing natural enemies. Do not apply when foliage is wet.

deltamethrin (Decis* 1.5EC): 1.5 to 2.4 oz/A (3 dh, REI 12h, Group 3A).

endosulfan (Thionex* 50W): 1 to 2 lb/A (2 dh, REI 24h, Group 2A).

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A (3 dh, REI 12h, Group 3A).

fenpropathrin (Danitol* 2.4EC): 10.7 to 16 oz/A (7 dh, REI 24, Group 3).

imidacloprid (Admire Pro): 7 to 10.5 oz/A (21 dh, REI 12h, Group 4A). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. DO NOT apply as a foliar spray. Note: Provado IS NOT registered for use on cucurbits.

kaolin (Surround WP): 25 to 50 lb/A or 1/4 to 1/2 lb/gal for backpack sprayer (0 dh, REI 4h). Suppression and repellence only. May be applied to transplants prior to setting in field. Use on seedlings and young plants. Product residue may need to be washed off if applied after fruit set. White residue may be minimized if applications stop when fruit is 1/4 of its expected harvest size. Follow label instructions for mixing. Generally compatible as a tank mix with other insecticides. OMRI listed.

lambda-cyhalothrin (Warrior*): 2.5 to 3.8 oz/A (1 dh, REI 24h, Group 3A).

malathion (Malathion 57 EC): 2 pt/A (1 dh, REI 12h, Group 1B). Not for cucumber. 

methomyl (Lannate* SP): 1/2 to 1 lb/A (1 dh for 1/2 lb/A, 3 dh for over 1/2 lb/A, REI 48h, Group 1A).

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A (0 dh, REI 12h, Group 3A).

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). OMRI listed.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A).

thiamethoxam (Actara): 2 to 3 oz/A (0 dh, REI 12h, Group 4). Highly toxic to bees exposed to direct treatment or residues on blooming crops. Do not apply or allow to drift to blooming crops or weeds. Wait at least 5 days before placing beehives in or near the treated field.

thiamethoxam (Platinum): 5 to 11 oz/A (30 dh, REI 12h, Group 4). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. DO NOT apply as a foliar spray.

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A (1 dh, REI 12h, Group 3A). 

Cutworm

Caterpillars hide under the soil surface adjacent to the plant stem during the day and feed on stems after dark. For best results, make application between midnight and dawn while cutworms are feeding aboveground. Synthetic pyrethroids (Group 3A) may work best during cool weather in April and May. See cutworms in the Pepper and Tomato (Outdoor) sections for more information on the black and variegated cutworms.

Bacillus thuringiensis aizawai (XenTari): 0.5 to 2 lb/A (0 dh, REI 4h, Group 11). Must be ingested; apply in evening before larvae are actively feeding and direct sprays to base of stem. OMRI listed.

beta-cyfluthrin (Baythroid* XL): 0.8 to 1.6 oz/A (0 dh, REI 12h, Group 3A).

bifenthrin (Capture* 2EC): 2.1 to 6.4 oz/A (7 dh, REI 12h, Group 3A).

carbaryl (10% Sevin Granules): 10 lb/A (3 dh, REI 12h, Group 1A).

deltamethrin (Decis* 1.5EC): 1 to 2.4 oz/A (3 dh, REI 12h, Group 3A).

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A (3 dh, REI 12h, Group 3A).

lambda-cyhalothrin (Warrior*): 2.5 to 3.8 oz/A (1 dh, REI 24h, Group 3A).

methomyl (Lannate* SP): 1/2 lb/A (1 dh for 1/2 lb/A, 3 dh for over 1/2 lb/A, REI 48h, Group 1A). For variegated cutworm.

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A (0 dh, REI 12h, Group 3A).

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to 12 oz/A (0 dh, REI 12h, Group 3A). 

zeta-cypermethrin (Mustang*): 1.4 to 4.3 oz/A (1 dh, REI 12h, Group 3A).  

Flea Beetle

Shiny black beetles less than 1/8” long that hop like fleas. Adults spend the winter under plant residue along tree lines or in the field. Numerous tiny feeding “shot holes” can injure leaves and stunt young plants. Management practices include clean cultivation, crop rotation, use of row covers, and applying spot treatments targeting young plants along the field edges. Row covers must be removed by bloom for pollination. Cucumbers and melons rarely require treatment for flea beetles. Most insecticides registered to control cucumber beetle will also control FB.

carbaryl (Sevin XLR Plus): 1 qt/A (3 dh, REI 12h, Group 1A). Highly toxic to bees; avoid use during bloom when bees are active; apply in evening. May encourage buildup of aphids by killing natural enemies. Do not apply when foliage is wet.

deltamethrin (Decis* 1.5EC): 1.5 to 2.4 oz/A (3 dh, REI 12h, Group 3A).

endosulfan (Thionex* 50W): 1 to 2 lb/A (2 dh, REI 24h, Group 2A).

lambda-cyhalothrin (Warrior*): 2.5 to 3.8 oz/A (1 dh, REI 24h, Group 3A).

methomyl (Lannate* SP): 1/2 to 1 lb/A (1 dh for 1/2 lb/A, 3 dh for over 1/2 lb/A, REI 48h, Group 1A).

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0 dh, REI 12h, Group 3A). OMRI listed.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to12 oz/A (0 dh, REI 12h, Group 3A).

thiamethoxam (Actara): 2 to 3 oz/A (0 dh, REI 12h, Group 4). Highly toxic to bees exposed to direct treatment or residues on blooming crops. Do not apply or allow to drift to blooming crops or weeds. Wait at least 5 days before placing beehives in or near the treated field.

thiamethoxam (Platinum): 5 to 11 oz/A (30 dh, REI 12h, Group 4). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. DO NOT apply as a foliar spray.

Two-spotted Spider Mite

Outbreaks are often caused by the use of broad-spectrum insecticides. Two-spotted spider mites (TSSM) tend to be prone to pesticide resistance. Watch for white speckling on the upper surface of leaves or webbing on the undersurface around leaf veins. Avoid early-season, broad-spectrum insecticide applications for other pests. Use selective products whenever possible. With most miticides (not bifenazate), use 2 applications, approximately 5 to 7 days apart, to help control immature mites that were in the egg stage and protected during the first application. Alternate between products after 2 applications to help prevent or delay resistance. For more information on TSSM, see the Eggplant section.

abamectin (Agri-Mek* 0.15EC): 8 to 16 oz/A (7 dh, REI 12h, Group 6).

bifenazate (Acramite 50WS): 0.75 to 1 lb/A (3 dh, REI 12h, Group 25).

bifenthrin (Capture* 2 EC): 5.1 to 6.4 oz/A (3 dh, REI 12h, Group 3A).

dicofol (Kelthane 50WSP): 1.25 lbs/A (2 dh, REI 48h, Group 2B). Do not apply more than twice per season.

fenpropathrin (Danitol* 2.4EC): 10.7 to 16 oz/A (7 dh, REI 24, Group 3).

lambda-cyhalothrin (Warrior*): 3.8 oz/A (1 dh, REI 24h, Group 3A). Suppression only.

neem oil (Trilogy): 0.5 to 2% solution in 25 to 100 gal water/A (0dh, REI 4h, Group 18). Avoid mid-day applications and ensure good coverage. OMRI listed.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal (0.5 dh, REI 12h, Group 25). Do not apply in midday sun or mix with copper, sulfur or oils. CT only.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A (7 dh, REI 12h, Group 23). Immature mites.

Seedcorn Maggot

Soils that are high in organic matter (decaying manure or vegetable matter), especially in cool wet springs, attract the egg-laying female flies. Not generally a problem in sandy soils.

Squash Bug and Squash Vine Borer

Squash bugs are generally controlled by clean cultivation, crop rotation and sprays for cucumber beetle, but are often resistant to all but a few insecticides (i.e. bifenthrin). If possible, rotate cucurbit crops between fields separated by at least 1/2 mile. Scout undersides of leaves for squash bug adults and eggs and treat if the copper-colored egg masses exceed one per plant. Time squash bug sprays to kill young nymphs which are easiest to control. Thorough coverage is necessary. Treat late in the day to reduce risk to bees. Keep headlands mowed and free of trash to reduce overwintering sites. Clean cultivation helps reduce populations, while use of mulches and reduced-tillage favors squash bug survival. Squash and pumpkins are preferred hosts compared with cucumbers and melons. In Southwestern states, melons are protected from bugs and cucurbit yellow vine disease using perimeter trap cropping. Plant a perimeter of squash (summer, Hubbard, marrow) a week or two before planting or transplanting melons. Spray adult bugs at the base of the trap crop with an effective insecticide just before melons emerge or before transplanting, and 5 to 10 days later. See squash bugs in the Pumpkin and Squash section for more information.

Squash vine borer is more likely to be a problem where infestations were heavy the previous year and on thick-stemmed squash and pumpkins. Monitor for moths with a Scentry Heliothis Trap from early June through early August. Treat if more than 5 moths per week are caught. Scout for squash vine borer starting in late June by inspecting stems for frass. Control newly hatched larvae by making 2 to 4 applications at one-week intervals beginning in late June or early July. Timing is important. Thoroughly treat stems. Treat late in the day to avoid injury to bees. Some selective materials, such as spinosad (SpinTor or Entrust), provide excellent control of hatching SVB larvae. See SVB in the Pumpkin and Squash section for more information.

acetamiprid (Assail 30 SG): 5.3 dry oz/A (7 dh, REI 12h, Group 4). Most effective on newly laid eggs and nymphs. Toxic to bees exposed to direct treatment; do not apply while bees are active.

azadirachtin (Neemix 4.5): 7 to 16 oz/A (0 dh, REI 12h, Group 18). Foliar application to young squash bug nymphs. OMRI listed.

bifenthrin (Capture* 2EC): 2.6 to 6.4 oz/A (3 dh, REI 12h, Group 3A).

carbaryl (Sevin XLR Plus): 1 qt/A (3 dh, REI 12h, Group 1A). For squash bug only. Highly toxic to bees; avoid use during bloom when bees are active. May encourage buildup of aphids by killing natural enemies. Do not apply when foliage is wet. Time sprays for early morning or late afternoon. Repeated application may cause plant injury.

endosulfan (Thionex* 50W): 1 to 2 lb/A (2 dh, REI 24h, Group 2A).

esfenvalerate (Asana* XL): 5.8 to 9.6 oz/A (3 dh, REI 12h, Group 3A).

lambda-cyhalothrin (Warrior*): 2.5 to 3.8 oz/A (1 dh, REI 24h, Group 3A).

permethrin (Pounce* 25WP): 6.4 to 12.8 oz/A (0 dh, REI 12h, Group 3A). Use high rate for squash bugs.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to12 oz/A (0 dh, REI 12h, Group 3A).

zeta-cypermethrin (Mustang*): 3 to 4.3 oz/A (1 dh, REI 12h, Group 3A).  

Whiteflies

See whiteflies in the tomato section for more information.

buprofezin (Courier 40SC): 9 to 13.6 oz/A (7 dh, REI 12h, Group 16). Insect growth regulator; target nymph stages. Allow at least 7 days between applications.

dinotefuran (Safari 20SG): 0.16 to 0.32 dry oz/1,000 sq ft or 3.5 to 7 dry oz/100 gal/20,000 sq ft (1 dh, REI 12h, Group 4). Cucumber and melon transplants while in greenhouse. Not for field use.

dinotefuran (Venom 20SG): 7 to 14 dry oz/A foliar or 18 to 21 dry oz/A soil (1 dh foliar, 21 dh soil, REI 12h, Group 4A). For resistance management purposes, do not use foliar spray after soil application or following another nicotinoid (Group 4A) insecticide application on the same crop. Highly toxic to bees, avoid foliar application during bloom. 

flonicamid (Beleaf 50SG): 2.8 dry oz/A (0 dh, REI 12, Group 9C). Suppression only.

lambda-cyhalothrin (Warrior*): 3.8 oz/A (1 dh, REI 24h, Group 3A). Suppression only.

pyrethrin (PyGanic EC5.0): 4.5 to 18 oz/A (0dh,REI 12h, Group 3A). OMRI listed. May be used in greenhouse or field.

pyrethrins + piperonyl butoxide (Pyrenone): 1 tsp/gal, or 1 to12 oz/A (0 dh, REI 12h, Group 3A). May be used in greenhouse or field.

pyriproxyfen (Knack): 8 to 10 oz/A (7 dh, REI 12h, Group 7). Insect growth regulator for long-term control of immature whiteflies. Does not control adults. No more than 2 applications per season, at least 14 days apart.

sodium tetraborohydrate decahydrate (Prev-AM): 50 oz/100 gal (0.5 dh, REI 12h, Group 25). Do not apply in midday sun or mix with copper, sulfur or oils. CT only.

spiromesifen (Oberon 2SC): 7 to 8.5 oz/A (7 dh, REI 12h, Group 23). Immature whiteflies only.

thiamethoxam (Actara): 3 to 5.5 oz/A (0 dh, REI 12h, Group 4). Highly toxic to bees exposed to direct treatment or residues on blooming crops. Do not apply or allow to drift to blooming crops or weeds. Wait at least 5 days before placing beehives in or near the treated field.

thiamethoxam (Platinum): 5 to 11 oz/A (30 dh, REI 12h, Group 4). Systemic insecticide used as an in-furrow, banded, drench, or drip irrigation application to the seed/seedling root zone during or after planting/transplanting operations. DO NOT apply as a foliar spray.